Power amplifier, chip, radio frequency front-end module, and transformer structure

Abstract

The present application discloses a power amplifier, a chip, a radio frequency front-end module, and a transformer structure. The power amplifier comprises a first power amplification circuit, a second power amplification circuit, and a balun, and the first power amplification circuit and the second power amplification circuit are respectively connected to the balun. The balun comprises: a primary coupling line, comprising a first input end and a second input end; and a secondary coupling line, comprising a first output end and a second output end, wherein a first wiring path of the primary coupling line follows a second wiring path of the secondary coupling line, the first wiring path is a wiring path from the first input end to the second input end, and the second wiring path is a wiring path from the first output end to the second output end. In the present application, the balun in the power amplifier has better coupling degree due to the primary coupling line and the secondary coupling line following each other, and the shapes and positions of the primary coupling line and the secondary coupling line can be flexibly adjusted, thereby facilitating miniaturization design of the radio frequency front-end module.

Description

Power amplifier, chip, RF front-end module and transformer structure

[0001] This application is based on three Chinese applications, namely, application number 202311432064.4 filed on October 31, 2023, entitled “Power amplifier, chip, RF front-end module and transformer structure”; application number 202311432078.6 filed on October 31, 2023, entitled “Power amplifier, chip and RF front-end module”; and application number 202322937062.2 filed on October 31, 2023, entitled “Power amplifier, chip and RF front-end module”, and claims priority. Technical Field

[0002] The present application relates to the field of radio frequency technology, and in particular to a power amplifier, a chip, a radio frequency front-end module, and a transformer structure. Background Art

[0003] RF power amplifiers are widely used in communications, broadcasting, radar, industrial processing, medical instruments, scientific research, and other fields. Currently, with the development of 5G communication systems, higher requirements are being placed on RF power amplifiers, such as meeting higher frequencies and higher-order QAM modulation.

[0004] Impedance matching is a crucial component of RF power amplifiers, and transformers are typically used to achieve impedance matching at the input or output of RF power amplifiers. However, traditional transformer structures typically occupy a large area, hindering the miniaturization of RF front-end modules.

[0005] Application Contents

[0006] This application proposes a power amplifier, chip, radio frequency front-end module and transformer structure, which can reduce the area occupied by the power amplifier and facilitate the miniaturization design of the radio frequency front-end module.

[0007] In a first aspect, an embodiment of the present application provides a power amplifier, comprising a first power amplifier circuit, a second power amplifier circuit, and a balun, wherein the first power amplifier circuit and the second power amplifier circuit are respectively connected to the balun; the balun comprises: a primary coupling line, wherein the primary coupling line comprises a first input end and a second input end; a secondary coupling line, wherein the secondary coupling line comprises a first output end and a second output end; wherein the first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

[0008] In a second aspect, an embodiment of the present application provides a chip comprising at least one power amplifier, wherein the power amplifier comprises a first power amplifier circuit, a second power amplifier circuit and a balun, wherein the first power amplifier circuit and the second power amplifier circuit are respectively connected to the balun; the balun comprises: a primary coupling line, wherein the primary coupling line comprises a first input end and a second input end; a secondary coupling line, wherein the secondary coupling line comprises a first output end and a second output end; wherein the first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

[0009] In a third aspect, an embodiment of the present application provides a radio frequency front-end module, comprising: a substrate, a power amplifier chip, arranged on the substrate; a balun, arranged on the substrate and connected to the power amplifier chip, the balun comprising: a primary coupling line, the primary coupling line comprising a first input end and a second input end; a secondary coupling line, the secondary coupling line comprising a first output end and a second output end; wherein the first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

[0010] In a fourth aspect, an embodiment of the present application provides a transformer structure, comprising: a primary coupling line, the primary coupling line comprising a first input terminal and a second input terminal; a secondary coupling line, the secondary coupling line comprising a first output terminal and a second output terminal; wherein the first routing path of the primary coupling line follows the second routing path of the secondary coupling line, and the first routing path is a routing path from the first input terminal to the second input terminal, and the second routing path is a routing path from the first output terminal to the second output terminal.

[0011] According to the first to fourth aspects of the embodiments of the present application, since the primary coupling line 201 and the secondary coupling line 202 of the balun / transformer structure follow each other from the starting point to the end point, each segment of the primary coupling line can be coupled to the corresponding segment of the secondary coupling line, and conversely, each segment of the secondary coupling line can also be coupled to the corresponding stage of the primary coupling line, thereby achieving a better coupling degree. In addition, the shape and layout of the primary coupling line 201 and the secondary coupling line 202 of the transformer structure / balun can be flexibly set to adapt to the layout of other circuits in the power amplifier, making the overall structure of the power amplifier more compact, thereby reducing the area occupied by the power amplifier and facilitating the miniaturization design of the RF front-end module.

[0012] In a fifth aspect, an embodiment of the present application provides a power amplifier, comprising a first power amplifier circuit, a second power amplifier circuit and a balun, wherein the balun comprises: a first coupling line, a first end of the first coupling line is connected to the output end or the input end of the first power amplifier circuit, and a second end is connected to the first ground end; a second coupling line, a first end of the second coupling line is connected to the output end or the input end of the second power amplifier circuit, and a second end is connected to the second ground end; a third coupling line, a first end of the third coupling line is connected to the output end or the input end of the power amplifier, and a second end is connected to the third ground end.

[0013] In a sixth aspect, an embodiment of the present application provides a chip, comprising a power amplifier as described in any one of the above items.

[0014] In the seventh aspect, an embodiment of the present application provides a radio frequency front-end module, comprising: a substrate and a power amplifier as described in any one of the above items; wherein a power amplifier chip is provided on the substrate, and the first power amplifier circuit and the second power amplifier circuit are integrated in the power amplifier chip; the balun is integrated in the power amplifier chip or is provided on the substrate.

[0015] According to aspects 5 to 7 of the embodiments of the present application, the main stage of the balun is split into two independent coupling lines, and the two main stage coupling lines are grounded separately through different ground terminals, so that the two main stage coupling lines can be physically independent of each other and can be connected in series in the circuit, thereby replacing the traditional integrated main stage coupling line. This method reduces the requirements for the line length of a single main stage coupling line, and there is no need to fix the main stage coupling line to a multi-turn winding shape in order to increase the line length. The shape and position of each coupling line can be flexibly set as needed, making the layout of the power amplifier more compact and conducive to the miniaturization design of the RF front-end module.

[0016] In an eighth aspect, an embodiment of the present application provides a power amplifier, including:

[0017] a first power amplifier circuit, the first power amplifier circuit comprising a plurality of first amplifier transistors connected in parallel, the plurality of first amplifier transistors being arranged along a first direction;

[0018] a second power amplifier circuit, the second power amplifier circuit comprising a plurality of second amplifier transistors connected in parallel, the plurality of second amplifier transistors being arranged along a second direction;

[0019] The first direction intersects with the second direction.

[0020] A ninth aspect of the present application provides a chip comprising the power amplifier of the eighth aspect.

[0021] In a tenth aspect, the present application provides a radio frequency front-end module, comprising: a substrate; and a chip, disposed on the substrate, wherein the chip integrates a power amplifier as in the eighth aspect.

[0022] In an eleventh aspect, the present application provides a radio frequency front-end module, characterized by comprising:

[0023] substrate;

[0024] A chip is disposed on the substrate, wherein the chip has a first edge and a second edge intersecting each other;

[0025] The chip is integrated with:

[0026] a first power amplifier circuit, the first power amplifier circuit comprising a plurality of first amplifier transistors connected in parallel, the plurality of first amplifier transistors being arranged along the first edge;

[0027] The second power amplifier circuit includes a plurality of second amplifier transistors connected in parallel, and the plurality of second amplifier transistors are arranged along the second edge.

[0028] According to aspects 8 to 11 of the embodiments of the present application, by arranging the first amplifying transistor and the second amplifying transistor in different directions, the layout of the internal circuit of the power amplifier is optimized, the area occupied by the power amplifier is reduced, and the miniaturization design of the RF front-end module is facilitated. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] FIG1 shows a schematic diagram of a transformer structure provided by related art.

[0031] FIG2 shows a schematic diagram of the transformer structure provided in an embodiment of the present application.

[0032] FIG3 shows a schematic diagram of the transformer structure provided by another embodiment of the present application.

[0033] FIG4 shows a schematic diagram of the transformer structure provided in yet another embodiment of the present application.

[0034] FIG5 shows a schematic diagram of the transformer structure provided in yet another embodiment of the present application.

[0035] FIG6 shows a schematic diagram of the transformer structure provided in yet another embodiment of the present application.

[0036] FIG7 shows a schematic structural diagram of a power amplifier provided in an embodiment of the present application.

[0037] FIG8 shows a schematic structural diagram of a power amplifier provided in another embodiment of the present application.

[0038] FIG9 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0039] FIG10 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0040] FIG11 shows a schematic layout diagram of primary coupling lines and secondary coupling lines provided in an embodiment of the present application.

[0041] FIG12 shows a schematic layout diagram of primary coupling lines and secondary coupling lines provided in another embodiment of the present application.

[0042] FIG13 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0043] FIG14 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0044] FIG15 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0045] FIG16 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0046] FIG17 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0047] FIG18 shows a schematic structural diagram of a power amplifier provided in yet another embodiment of the present application.

[0048] FIG19 shows a schematic diagram of a chip structure provided in an embodiment of the present application.

[0049] FIG20 shows a schematic diagram of a chip structure provided in another embodiment of the present application.

[0050] FIG21 shows a schematic diagram of a chip structure provided in yet another embodiment of the present application.

[0051] FIG22 shows a schematic structural diagram of a radio frequency front-end module provided in an embodiment of the present application.

[0052] FIG23 shows a schematic diagram of the circuit structure of a power amplifier provided in an embodiment of the present application.

[0053] FIG24 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0054] FIG25 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0055] FIG26 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0056] FIG27 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0057] FIG28 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0058] FIG29 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0059] FIG30 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0060] FIG31 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0061] Figure 32 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0062] Figure 33 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0063] Figure 34 shows a schematic diagram of the circuit structure of another power amplifier provided in an embodiment of the present application.

[0064] FIG35 shows a schematic diagram of a balun structure provided in an embodiment of the present application.

[0065] FIG36 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0066] Figure 37 shows a schematic structural diagram of a radio frequency front-end module provided in an embodiment of the present application.

[0067] Figure 38 shows a schematic structural diagram of another RF front-end module provided in an embodiment of the present application.

[0068] FIG39 shows a schematic structural diagram of a power amplifier provided by the related art.

[0069] Figure 40 shows a schematic structural diagram of a power amplifier provided in an embodiment of the present application.

[0070] Figure 41 shows a schematic structural diagram of another power amplifier provided in an embodiment of the present application.

[0071] Figure 42 shows a circuit diagram of a power amplifier provided in an embodiment of the present application.

[0072] Figure 43 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0073] Figure 44 shows a schematic diagram of a balun structure provided in an embodiment of the present application.

[0074] Figure 45 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0075] Figure 46 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0076] Figure 47 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0077] Figure 48 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0078] Figure 49 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0079] Figure 50 shows a schematic diagram of another balun structure provided in an embodiment of the present application.

[0080] Figure 51 shows a structural schematic diagram of another power amplifier provided in an embodiment of the present application.

[0081] Figure 52 shows a schematic structural diagram of another power amplifier provided in an embodiment of the present application.

[0082] Figure 53 shows a structural schematic diagram of another power amplifier provided in an embodiment of the present application.

[0083] Figure 54 shows a schematic structural diagram of another power amplifier provided in an embodiment of the present application.

[0084] Figure 55 shows a schematic structural diagram of another power amplifier provided in an embodiment of the present application.

[0085] Figure 56 shows a schematic structural diagram of another power amplifier provided in an embodiment of the present application.

[0086] Figure 57 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0087] Figure 58 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0088] Figure 59 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0089] Figure 60 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0090] Figure 61 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0091] Figure 62 shows a circuit diagram of another power amplifier provided in an embodiment of the present application.

[0092] Figure 63 shows a structural diagram of a radio frequency front-end module provided in an embodiment of the present application.

[0093] Figure 64 shows a schematic structural diagram of another RF front-end module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0094] In order to enable those skilled in the art to better understand the present invention, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0095] The terms "first," "second," and the like in this application are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0096] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0097] A transformer is a device that uses the principle of electromagnetic induction to change AC voltage. It usually has a primary coil and a secondary coil. In power amplifiers, transformers can also be used for impedance matching. In the related art, as shown in Figure 1, the primary coil has two input ports, in1 and in2, and the secondary coil has two output ports, out1 and out2. The input ports in1 and in2 of the primary coil are usually located near the front-stage circuit, while the output ports out1 and out2 of the secondary coil are located near the back-stage circuit to facilitate the connection between the primary coil and the front-stage circuit and the secondary coil and the back-stage circuit. The related art usually takes a position between the front-stage circuit and the back-stage circuit as the center, with one input port or output port as the starting point and the other input port or output port as the end point, and the primary coil and secondary coil are wound respectively. As a result, the overall shape of the transformer is a nearly closed ring. Because the internal space of the ring is insufficient to accommodate the front-stage circuit or the back-stage circuit, the front-stage circuit and the back-stage circuit can only be arranged on both sides of the transformer, which wastes the internal space of the ring, resulting in the power amplifier occupying a large area as a whole, which is not conducive to the miniaturization design of the RF front-end module. In addition, the gap between the two input ports in1 and in2 of the primary coil cannot couple with the secondary coil, and the gap between the two output ports out1 and out2 of the secondary coil cannot couple with the primary coil, resulting in the coupling degree of the transformer structure being affected.

[0098] To this end, the embodiments of the present application provide a transformer structure, a power amplifier, and a radio frequency front-end module, which can reduce the area occupied by the power amplifier and facilitate the miniaturization design of the radio frequency front-end module.

[0099] Please refer to Figure 2, which shows a transformer structure provided by an embodiment of the present application. As shown in Figure 2, the transformer structure 20 includes a primary coupling line 201 and a secondary coupling line 202, wherein the primary coupling line 201 includes a first input terminal In1 and a second input terminal In2, and the secondary coupling line 202 includes a first output terminal Out1 and a second output terminal Out2. The primary coupling line 201 is the input stage of the transformer structure 20, which is used to receive an RF input signal from a previous circuit; the secondary coupling line 202 is the output stage of the transformer structure 20, which is used to couple with the primary coupling line 201 to generate an RF signal and output the coupled RF signal to a subsequent circuit.

[0100] In the embodiment of the present application, the routing path of the primary coupling line 201 from the first input terminal In1 to the second input terminal In2 is referred to as the first routing path, and the routing path of the secondary coupling line 202 from the first output terminal Out1 to the second output terminal Out2 is referred to as the second routing path, wherein the first routing path follows the second routing path. In other words, if the first input terminal In1 is used as the starting point of the primary coupling line 201, the second input terminal In2 is used as the end point of the primary coupling line 201, the first output terminal Out1 is used as the starting point of the secondary coupling line 202, and the second output terminal Out2 is used as the end point of the secondary coupling line 202, then the primary coupling line 201 and the secondary coupling line 202 each have substantially the same direction from the starting point to the end point and exhibit substantially the same shape.

[0101] In the embodiments of the present application, "following" means that each segment of the primary coupling line is approximately parallel to the corresponding segment of the secondary coupling line. For example, if the primary coupling line 201 and the secondary coupling line 202 are both straight or curved, the primary coupling line and the secondary coupling line are generally parallel to each other. If the primary coupling line 201 and the secondary coupling line 202 each include one or more bends, the primary coupling line 201 and the secondary coupling line 202 can be divided into multiple segments based on the bends. In this case, each segment of the primary coupling line 201 is approximately parallel to the corresponding segment of the secondary coupling line 202.

[0102] Since the paths of the primary coupling line 201 and the secondary coupling line 202 from the starting point to the end point follow each other, each segment of the primary coupling line can be coupled with the corresponding segment of the secondary coupling line, and vice versa, each segment of the secondary coupling line can also be coupled with the corresponding stage of the primary coupling line, resulting in a better coupling degree than the structure shown in FIG1 .

[0103] On the other hand, because the primary coupled line 201 and the secondary coupled line 202 are coupled to each other, the distance between them is very small, and they follow each other. Therefore, the starting points of the primary coupled line 201 and the secondary coupled line 202 are close to each other, and the end points are also close to each other. In other words, the first input end In1 of the primary coupled line 201 and the first output end Out1 of the secondary coupled line 202 are arranged close to each other, and the second input end In2 of the primary coupled line 201 and the second output end Out2 of the secondary coupled line 202 are arranged close to each other.

[0104] Based on this, the primary coupling line 201 and the secondary coupling line 202 of the transformer structure are generally linear structures, and their shapes and layout positions can be flexibly set to adapt to the layout of other circuits in the power amplifier, making the overall structure of the power amplifier more compact, thereby reducing the area occupied by the power amplifier, and facilitating the miniaturization design of the RF front-end module.

[0105] For example, as shown in FIG3(a), the primary coupling line 201 and the secondary coupling line 202 are both arranged in a straight line. Thus, the overall transformer structure presents a narrow, elongated structure, without any unusable enclosed space, and the overall occupied area is very small. In this case, the front-stage and rear-stage circuits can be arranged on both sides of the transformer structure, and the distance between the front-stage and rear-stage circuits only needs to be slightly greater than the width of the transformer structure, making the overall layout of the power amplifier and RF front-end module compact and neat.

[0106] For example, as shown in FIG3( b ), both the primary coupling line 201 and the secondary coupling line 202 are arranged in a zigzag pattern, resulting in a transformer structure that is narrow and has one or more bends. This allows for flexible bending to accommodate the positional relationship between the front-stage and rear-stage circuits, making the layout of the front-stage and rear-stage circuits and the transformer structure more compact. The bending patterns of the primary coupling line 201 and the secondary coupling line 202 can be designed based on the layout requirements of the front-stage and rear-stage circuits. For example, when a gap is required between the front-stage circuit and the rear-stage circuit, the primary coupling line 201 and the secondary coupling line 202 can be interspersed between the front-stage circuit and the rear-stage circuit as shown in (b) in Figure 3 to make the overall layout more compact; when the front-stage circuit and the rear-stage circuit need to be set close to each other, the primary coupling line 201 and the secondary coupling line 202 can adopt other bending methods, such as bending in a manner of surrounding / semi-surrounding the front-stage circuit and / or the rear-stage circuit, so that the front-stage circuit and the rear-stage circuit can be close to each other, and the space inside the bending part of the transformer structure can be utilized, thereby making the layout of the power amplifier and the RF front-end module more compact and occupying a smaller area.

[0107] For example, as shown in FIG4 , the primary coupling line 201 and the secondary coupling line 202 are both arranged in a roughly L-shape, and the transformer structure as a whole is an L-shaped structure. The inner side of the bend of the L-shaped structure can be used to layout at least part of the circuit elements in the front-stage circuit and / or the rear-stage circuit, that is, the transformer structure can be arranged semi-surrounding the front-stage circuit or the rear-stage circuit or both to utilize the space at the bend of the L-shaped structure, thereby making the layout of the power amplifier and the RF front-end module more compact and occupying a smaller area.

[0108] Optionally, when a relatively wide gap is required between the pre-stage circuit and the post-stage circuit, one of the pre-stage circuit and the post-stage circuit can be positioned inside the bend of the L-shaped structure, while the other can be positioned outside the bend of the L-shaped transformer structure, as shown in FIG4(a). When the pre-stage circuit and the post-stage circuit need to be positioned adjacent to each other, both can be positioned inside the bend of the L-shaped transformer structure, as shown in FIG4(b). This allows the pre-stage circuit and the post-stage circuit to be positioned close together, and the space inside the L-shaped bend can be utilized, thereby making the layout of the power amplifier and RF front-end module more compact and occupying a smaller area.

[0109] For example, as shown in FIG5 , the primary coupling line 201 and the secondary coupling line 202 are both arranged in a U-shape, and the transformer structure as a whole is a U-shaped structure. The inner side of the U-shaped structure can be used to layout at least part of the circuit elements in the front-stage circuit and / or the back-stage circuit, so that the space inside the U-shaped structure can be reasonably utilized, thereby making the layout of the power amplifier and the RF front-end module more compact and occupying a smaller area.

[0110] Optionally, when a relatively wide gap is required between the pre-stage circuit and the post-stage circuit, one of the pre-stage circuit and the post-stage circuit is positioned inside the U-shaped transformer structure, while the other is positioned outside the U-shaped structure. When the pre-stage circuit and the post-stage circuit need to be positioned adjacent to each other, both can be positioned inside the U-shaped transformer structure, as shown in (a) or (b) of FIG5 . This allows the pre-stage circuit and the post-stage circuit to be positioned close together, and the space inside the U-shaped structure can be utilized, thereby making the layout of the power amplifier and RF front-end module more compact and occupying a smaller area.

[0111] As an embodiment, in the above-mentioned examples of straight lines, zigzag lines, L-shapes, or U-shapes, the length of the primary coupling line 201 is equal to the length of the secondary coupling line 202, thereby increasing the coupling area between the primary coupling line 201 and the secondary coupling line 202 and improving the coupling degree of the transformer structure. For zigzag, L-shape, or U-shaped transformer structures, the length of the primary coupling line 201 can be made equal to the length of the secondary coupling line 202 by manipulating the position of the bend. Taking the L-shaped transformer structure as an example, the primary coupling line 201 and the secondary coupling line 202 of the L-shaped transformer structure each include two line segments connected at a second angle. By changing the inner and outer positional relationship of the primary coupling line 201 and the secondary coupling line 202 at the bend, such that one line segment of the primary coupling line 201 is outside the secondary coupling line 202 and another line segment is inside the secondary coupling line 202, the lengths of the primary coupling line 201 and the secondary coupling line 202 can be made equal or approximately equal. A U-shaped transformer structure or other zigzag transformer structures are similar to this. By changing the internal and external positional relationship between the primary coupling line 201 and the secondary coupling line 202 at at least one bend, the length of the primary coupling line 201 can be made equal to the length of the secondary coupling line 202. The specific details are not repeated here.

[0112] It should be understood that for a zigzag, L-shaped or U-shaped transformer structure, in order to avoid sudden changes in the current direction on the primary coupling line and the secondary coupling line, the bending parts of the zigzag or L-shaped primary coupling line and the secondary coupling line can also be designed as arc shapes to provide a buffer when the current direction changes, thereby reducing the loss of the RF signal and improving the RF signal transmission efficiency.

[0113] For example, as shown in FIG6 , the primary coupling line 201 and the secondary coupling line 202 are both arranged in an arc shape. Since the primary coupling line 201 and the secondary coupling line 202 follow each other and are both open arcs, the transformer structure formed thereby also presents an open arc structure. The arc structure has openings at both ends, and at least some circuit elements in the front-stage circuit or the back-stage circuit can be arranged on the inner side of the arc structure, thereby effectively utilizing the space inside the arc, reducing area waste, and making the layout of the power amplifier and the RF front-end module more compact and occupying a smaller area. Moreover, the direction of the current transmitted in the arc coupling line changes relatively slowly, which can reduce the loss of the RF signal and improve the efficiency of RF signal transmission.

[0114] Optionally, the central angle of the arc formed by the primary coupling line 201 and the secondary coupling line 202 is less than or equal to 270°, that is, the arc formed by the primary coupling line 201 and the secondary coupling line 202 is less than or equal to 3 / 4 of a circle, so that the arc presented by the transformer structure has an opening greater than or equal to 1 / 4 of a circle, thereby facilitating the layout of at least part of the circuit elements of the front-stage circuit or the back-stage circuit inside the arc structure.

[0115] Optionally, the central angle of the arc formed by the primary coupling line 201 and the secondary coupling line 202 is less than or equal to 180°, that is, the arc formed by the primary coupling line 201 and the secondary coupling line 202 is less than or equal to a semicircle, so that the arc presented by the transformer structure has an opening greater than or equal to a semicircle, so as to facilitate the layout of more circuit elements inside the arc structure.

[0116] Optionally, the central angle of the arc formed by the primary coupling line 201 and the secondary coupling line 202 is greater than or equal to 90°, that is, the arc formed by the primary coupling line 201 and the secondary coupling line 202 is greater than or equal to 1 / 4 circle, so that the primary coupling line 201 and the secondary coupling line 202 have a certain routing length, thereby meeting the inductance required for impedance matching.

[0117] As an embodiment, when the primary coupling line 201 and the secondary coupling line 202 adopt an arc-shaped structure, the radius and central angle of the arc structure can be determined based on the circuit area of ​​the preceding circuit or the subsequent circuit, and the inductance required for impedance matching. The radius of the arc structure can be positively correlated with the inductance required for impedance matching and the circuit area that needs to be arranged inside the arc structure. Thus, at the same central angle, the larger the radius, the larger the space inside the arc structure, which can accommodate more circuit elements, and the longer the traces, which can provide greater inductance. Furthermore, the central angle of the arc structure can be negatively correlated with the circuit area that needs to be arranged inside the arc structure. That is, the larger the circuit area that needs to be arranged inside, the smaller the central angle of the arc structure, and the larger the corresponding opening, which facilitates the layout of circuit elements.

[0118] In each of the above examples, the front-stage circuit refers to the circuit connected to the primary coupling line 201, and the output signal of the front-stage circuit is the input signal of the transformer structure. The rear-stage circuit refers to the circuit connected to the secondary coupling line 202, and the signal output by the secondary coupling line 202 is the input signal of the rear-stage circuit.

[0119] For example, when the transformer structure serves as an input impedance matching circuit in a power amplifier, its subsequent circuitry may include a power amplifier circuit. For example, the primary coupling line 201 of the transformer structure may be used to receive a radio frequency signal to be amplified, and the secondary coupling line 202 may be used to connect to the input end of the power amplifier circuit. After the radio frequency signal to be amplified undergoes input impedance matching through the transformer structure, it is then amplified by the power amplifier circuit.

[0120] Exemplarily, when the transformer structure serves as an inter-stage impedance matching circuit in a multi-stage power amplifier, its pre-stage circuit and post-stage circuit can respectively be power amplifier circuits at different stages of the multi-stage power amplifier. Taking a two-stage power amplifier as an example, the primary coupling line 201 of the transformer structure can be used to connect to the output of the first-stage power amplifier to receive the RF signal output by the first-stage power amplifier circuit. The secondary coupling line 202 can be used to connect to the input of the second-stage power amplifier circuit to input the RF signal, which has undergone inter-stage impedance matching, into the second-stage power amplifier circuit for second-stage power amplification.

[0121] For example, when the transformer structure is used as an output impedance matching circuit in a power amplifier, its preceding circuit may include a power amplifier circuit. The primary coupling line 201 of the transformer structure can be used to receive the RF signal from the power amplifier circuit, while the secondary coupling line 202 outputs the coupled RF signal after output impedance matching to other modules in the RF front-end module, such as an RF switch module.

[0122] It should be understood that some RF front-end modules may include multiple impedance matching circuits. Therefore, this transformer structure can be applied to one or more impedance matching circuits in the RF front-end module. When multiple impedance matching circuits all use the aforementioned transformer structure, for some transformer structures, the power amplifier circuit is the front-end circuit, while for other transformer structures, the power amplifier circuit is the back-end circuit.

[0123] In the embodiment of the present application, the transformer structure can be integrated into the chip or provided on the substrate, and the specific setting can be based on the application needs. For example, the substrate can provide a larger routing space than the chip, thereby enabling a larger inductance. Therefore, when the primary coupling line and the secondary coupling line of the transformer are required to have a larger inductance, the transformer structure can be provided on the substrate; when the inductance requirements for the primary coupling line and the secondary coupling line are relatively small, the transformer structure can be provided in the chip, specifically in the chip where the power amplifier is located. For another example, when the transformer structure is used as an inter-stage impedance matching circuit of a power amplifier, the transformer structure needs to be connected to the multi-stage power amplification circuits of the power amplifier respectively, and the inductance requirements for the primary coupling line and the secondary coupling line are not high, then the transformer structure can be integrated into the chip where the power amplifier is located to facilitate circuit connection.

[0124] In the embodiment of the present application, since the primary coupling line and the secondary coupling line are arranged following each other, the length of each coupling line is approximately the same, and one primary coupling line and one secondary coupling line can achieve an inductance ratio of approximately 1:1. In some application scenarios, if an inductance ratio different from 1:1 is required, the number of primary coupling lines 201 and / or secondary coupling lines 202 can be set to multiple, and an inductance ratio different from 1:1 can be achieved by connecting multiple primary coupling lines in series and / or multiple secondary coupling lines 202 in series. For example, when an inductance ratio of 2:1 is required, two primary coupling lines and one secondary coupling line can be set, and the two primary coupling lines can be connected in series to have an inductance approximately twice that of the secondary, thereby achieving an inductance ratio of 2:1. At this time, in order to improve the coupling between the primary coupling line and the secondary coupling line, the secondary coupling line can be set between the two primary coupling lines so that the secondary coupling line can couple with both primary coupling lines, thereby improving the coupling of the transformer structure. Similarly, when a 1:2 inductance ratio is required, one primary coupling line and two secondary coupling lines can be provided. The two secondary coupling lines are connected in series to have an inductance approximately twice that of the primary, thereby achieving a 1:2 inductance ratio. In this case, to improve the coupling between the primary and secondary coupling lines, the primary coupling line can be placed between the two secondary coupling lines, so that both secondary coupling lines can couple well with the primary coupling line.

[0125] In at least one embodiment, to improve the coupling between the primary and secondary coupling lines, at least one primary coupling line can be split into two parallel coupling lines, and the secondary coupling line can be positioned between the two split primary coupling lines to strengthen the coupling between the primary and secondary coupling lines. For example, the line width of each primary coupling line can be slightly smaller than the line width of the secondary coupling line, or can be maintained approximately the same as the line width of the secondary coupling line, thereby improving the coupling of the transformer structure. Alternatively, at least one secondary coupling line can be split into two parallel coupling lines, and the primary coupling line can be positioned between the two split secondary coupling lines to strengthen the coupling between the primary and secondary coupling lines. Optionally, the line width of each split secondary coupling line can be slightly smaller than the line width of the primary coupling line, or can be maintained approximately the same as the line width of the primary coupling line, further improving the coupling of the transformer structure.

[0126] In at least one embodiment, the primary coupling line or the secondary coupling line can be split into more lines, and the primary coupling lines and the secondary coupling lines are arranged alternately to further increase the coupling area between the primary coupling lines and the secondary coupling lines and improve the coupling degree of the transformer structure.

[0127] Optionally, when there are multiple primary coupling lines and multiple secondary coupling lines located in the same plane, to ensure balance between the primary and secondary coupling lines, the coupling lines on both sides can be of the same type. For example, if both sides are primary coupling lines or both sides are secondary coupling lines, the difference between the number of primary and secondary coupling lines needs to be 1. Exemplarily, the transformer structure can include N primary coupling lines and M secondary coupling lines, with the N primary coupling lines and the M secondary coupling lines interleaved; where N and M are both positive integers, and N = M + 1 or N = M - 1. For example, when there is one more primary coupling line than secondary coupling line, i.e., N = M + 1, the primary coupling line and the secondary coupling line are interleaved in the order of primary → secondary ... → primary; when there is one more secondary coupling line than primary coupling line, i.e., N = M - 1, the primary coupling line and the secondary coupling line are interleaved in the order of secondary → primary ... → secondary. In this way, the transformer structure's coupling can be improved while ensuring balance.

[0128] According to the above embodiment, the number of primary coupling lines 201 and secondary coupling lines 202 can be one or more, respectively. When there are multiple primary coupling lines 201, the multiple primary coupling lines 201 can be connected in series or in parallel; when there are multiple secondary coupling lines 202, the multiple secondary coupling lines 202 can be connected in series or in parallel. The number of primary coupling lines 201 and the number of secondary coupling lines 202, as well as the connection relationship between the multiple primary coupling lines 201 and the multiple secondary coupling lines 202, can be set based on the required inductance ratio and coupling degree.

[0129] In some embodiments, when there is only one primary coupling line and one secondary coupling line, the primary and secondary coupling lines are located in the same plane. When there are multiple primary or secondary coupling lines, at least one primary coupling line and at least one secondary coupling line are located in the same plane. Placing the at least one primary coupling line and the at least one secondary coupling line in the same plane allows them to be fabricated on the same metal layer of the chip or substrate, thereby reducing the number of metal layers occupied by the balun and lowering costs. Furthermore, fabricating them in the same metal layer allows the thickness of the primary coupling line to be the same as that of the secondary coupling line, resulting in improved balun coupling.

[0130] The present application also provides a power amplifier, as shown in FIG7 . The power amplifier 70 may include a first power amplifier circuit 701, a second power amplifier circuit 702, and a balun 703. The first power amplifier circuit 701 and the second power amplifier circuit 702 are respectively connected to the balun 703. The balun 703 includes a primary coupling line 7031 and a secondary coupling line 7032. The primary coupling line 7031 includes a first input terminal In1 and a second input terminal In2. The secondary coupling line 7032 includes a first output terminal Out1 and a second output terminal Out2.

[0131] In the embodiment of the present application, the power amplifier 70 includes at least one differential power amplifier circuit. For example, the first power amplifier circuit 701 and the second power amplifier circuit 702 may constitute a differential power amplifier circuit. Alternatively, the power amplifier 70 may be a push-pull power amplifier or a balanced power amplifier, or a combination of at least one single-ended power amplifier circuit and at least one differential power amplifier circuit.

[0132] Optionally, the balun 703 is used to achieve input impedance matching or output impedance matching of the differential power amplifier circuit. When the power amplifier is a multi-stage power amplifier, it can also be used to achieve inter-stage impedance matching of the multi-stage power amplifier.

[0133] As an implementation method, the balun 703 can be used for output impedance matching of the differential power amplifier circuit and to realize balanced-unbalanced conversion of the RF signal, that is, the balanced RF signal amplified and output by the first power amplifier circuit 701 and the second power amplifier circuit 702 is converted into an unbalanced RF signal for output, for example, output to the switching circuit at the back end of the power amplifier, and the switching circuit selectively outputs the unbalanced RF signal to the antenna port.

[0134] As another embodiment, the balun 703 can be used for input impedance matching or inter-stage impedance matching of the differential power amplifier circuit. When the input RF signal of the differential power amplifier circuit is an unbalanced signal, or when the front ends of the first power amplifier circuit 701 and the second power amplifier circuit 702 are also provided with single-ended power amplifier circuits, the balun 703 is also used to realize unbalanced-balanced conversion of the RF signal, that is, converting the unbalanced RF input signal into a balanced RF signal, and the first power amplifier circuit 701 and the second power amplifier circuit 702 perform power amplification on the balanced RF signal.

[0135] In the embodiment of the present application, the routing path of the primary coupling line 7031 from the first input terminal In1 to the second input terminal In2 is referred to as the first routing path, and the routing path of the secondary coupling line 7032 from the first output terminal Out1 to the second output terminal Out2 is referred to as the second routing path, wherein the first routing path follows the second routing path. In other words, if the first input terminal In1 is used as the starting point of the primary coupling line 7031, the second input terminal In2 is used as the end point of the primary coupling line 7031, the first output terminal Out1 is used as the starting point of the secondary coupling line 7032, and the second output terminal Out2 is used as the end point of the secondary coupling line 7032, then the primary coupling line 7031 and the secondary coupling line 7032 each have substantially the same direction from the starting point to the end point and exhibit substantially the same shape.

[0136] Since the paths of the primary coupling line 7031 and the secondary coupling line 7032 from the starting point to the end point follow each other, each segment of the primary coupling line can be coupled with the corresponding segment of the secondary coupling line. Conversely, each segment of the secondary coupling line can also be coupled with the corresponding stage of the primary coupling line, resulting in a better coupling degree than the structure shown in FIG1 .

[0137] On the other hand, because the primary coupling line 7031 and the secondary coupling line 7032 are coupled to each other, the distance between them is very small, and they follow each other. Therefore, the starting points and end points of the primary coupling line 7031 and the secondary coupling line 7032 are close to each other. In other words, the first input end In1 of the primary coupling line 7031 and the first output end Out1 of the secondary coupling line 7032 are arranged close to each other, and the second input end In2 of the primary coupling line 7031 and the second output end Out2 of the secondary coupling line 7032 are arranged close to each other.

[0138] Based on this, the primary coupling line 7031 and the secondary coupling line 7032 of the transformer structure are generally linear structures, and their shape and layout can be flexibly set to adapt to the layout of other circuits in the power amplifier, making the overall structure of the power amplifier more compact, thereby reducing the area occupied by the power amplifier, and facilitating the miniaturization design of the RF front-end module.

[0139] In some embodiments, the balun 703 may adopt the same structure as the transformer structure 20 of any of the aforementioned embodiments. For example, the primary coupling line and the secondary coupling line may be arranged in a straight line, a broken line, an arc, a U shape, an L shape, etc. For details, please refer to the description of the aforementioned embodiments, which will not be repeated here.

[0140] In some embodiments, as shown in Figure 8, the primary coupling line 7031 includes a first primary coupling line 7031a and a second primary coupling line 7031b. The first primary coupling line 7031a and the second primary coupling line 7031b have first input terminals In1a and In1b and second input terminals In2a and In2b, respectively. The routing path of the first primary coupling line 7031a from the first input terminal In1a to the second input terminal In2a and the routing path of the second primary coupling line 7031b from the first input terminal In1b to the second input terminal In2b are both referred to as first routing paths. The first routing paths of the first primary coupling line 7031a and the second primary coupling line 7031b both follow the second routing path of the secondary coupling line 7032. In the embodiment of the present application, the secondary coupling line 7032 is arranged between the first primary coupling line 7031a and the second primary coupling line 7031b, so as to have a high coupling degree with both the first primary coupling line 7031a and the second primary coupling line 7031b, thereby improving the coupling coefficient of the balun 703.

[0141] Optionally, the first primary coupling line 7031a and the second primary coupling line 7031b can be connected in series or in parallel. The inductance of a coupling line is primarily related to its length. When two coupling lines are connected in series, this is equivalent to increasing the length of the coupling line, and the inductance also increases accordingly. When two coupling lines of the same length are connected in parallel, this is equivalent to increasing the width of the coupling line, but keeping the length unchanged, which has a smaller impact on the inductance. Therefore, in some embodiments, the ratio of primary to secondary inductance can be adjusted by increasing the number of primary / secondary coupling lines and connecting multiple primary / secondary coupling lines in series.

[0142] As an embodiment, the balun 703 is used for output impedance matching of the power amplifier. When the first primary coupling line 7031a and the second primary coupling line 7031b are connected in parallel, the input end of the balun 703 is connected to the output ends of the first power amplifier circuit 701 and the second power amplifier circuit 702. Specifically, as shown in FIG8 , the first input end In1a of the first primary coupling line 7031a and the first input end In1b of the second primary coupling line 7031b are respectively connected to the output end of the first power amplifier circuit 701, and the second input end In2a of the first primary coupling line 7031a and the second input end In2b of the second primary coupling line 7031b are respectively connected to the output end of the second power amplifier circuit 702. The first output end Out1 of the secondary coupling line 7032 is used to connect to the signal transmission end 704, and the second output end Out2 of the secondary coupling line 7032 is grounded.

[0143] In this embodiment, the balun 703 is a balanced-unbalanced balun that can convert the balanced (differential) signal received at the input end into an unbalanced (single-ended) signal so that it can be received by the single-ended circuit (such as an RF switch) of the subsequent stage. For example, the first output end Out1 of the balun 703 can be connected to the RF switch in the RF front-end module, so that when the RF switch is turned on, the amplified RF signal is transmitted to the antenna port connected to the RF switch, and then transmitted through the antenna connected to the antenna port. At this time, the balun 703 serves as the output balun of the power amplifier, connected between the power amplifier and the subsequent stage circuit, and can match the output impedance of the power amplifier with the input impedance of the subsequent stage circuit, thereby reducing the loss of the RF signal during transmission.

[0144] In this embodiment, by splitting the primary coupling line 7031 into two parallel coupling lines 7031a and 7031b, the secondary coupling line 7032 can be sandwiched between the two primary coupling lines 7031a and 7031b, thereby improving the coupling degree of the balun.

[0145] Because the two primary coupling lines 7031a and 7031b are connected in parallel, their impact on inductance is minimal. When the two primary coupling lines 7031a and 7031b are the same length as the secondary coupling line 7032, the ratio of the primary and secondary inductances of the balun structure is approximately 1:1. Alternatively, the width of the first and second primary coupling lines can be slightly smaller than the width of the secondary coupling line, or maintained approximately the same as the width of the secondary coupling line, to further improve the coupling of the balun 703.

[0146] As an embodiment, the balun 703 is used for output impedance matching of the power amplifier. When the first primary coupling line 7031a and the second primary coupling line 7031b are connected in series, the input end of the balun 703 is connected to the output end of the first power amplifier circuit 701 and the second power amplifier circuit 702. Specifically, as shown in FIG9 , the first input end In1a of the first primary coupling line 7031a is used to connect to the output end of the first power amplifier circuit 701, and the second input end In2a of the first primary coupling line 7031a is used to be grounded; the first input end In1b of the second primary coupling line 7031b is used to be grounded, and the second input end In2b of the second primary coupling line 7031b is used to connect to the output end of the second power amplifier circuit 702; the first output end Out1 of the secondary coupling line 7032 is used to connect to the signal transmission end, and the second output end Out2 of the secondary coupling line 7032 is used to be grounded.

[0147] In this embodiment, since the second input terminal In2a of the first primary coupled line 7031a and the first input terminal In1b of the second primary coupled line 7031b are both grounded, the first primary coupled line 7031a and the second primary coupled line 7031b are effectively connected in series between the output terminal of the first power amplifier circuit 701 and the output terminal of the second power amplifier circuit 702, thereby receiving the balanced signal output by the differential power amplifier circuit including the first power amplifier circuit 701 and the second power amplifier circuit 702. The secondary coupled line 703 has one end grounded and the other end serving as an output, thereby converting the balanced signal received by the primary circuit into an unbalanced signal for output. Similar to the previous embodiment, the balun 703 can also be used to achieve impedance matching between the preceding and succeeding circuits, thereby reducing signal loss during transmission.

[0148] The first primary coupling line 7031a, the second primary coupling line 7031b, and the secondary coupling line 703 are of the same length to improve the balun's coupling coefficient. Since the first primary coupling line 7031a and the second primary coupling line 7031b are connected in series, the length of the primary coupling line is doubled, which is twice the length of the secondary coupling line. Therefore, the balun 703 can achieve a 2:1 inductance ratio.

[0149] In this embodiment, by splitting the primary coupling line 7031 into two coupling lines 7031a and 7031b, the secondary coupling line 7032 can be sandwiched between the two primary coupling lines 7031a and 7031b, thereby improving the coupling degree of the balun. In addition, by connecting the two coupling lines 7031a and 7031b in series, the inductance of the primary coupling line can be increased without increasing the length of a single coupling line, thereby adjusting the ratio of the balun inductances and meeting the needs of application scenarios with high inductance requirements using a smaller area.

[0150] As an embodiment, the balun 703 is used to match the input impedance or inter-stage impedance of the power amplifier. When the first primary coupling line 7031a and the second primary coupling line 7031b are connected in parallel, the output end of the balun 703 is connected to the input ends of the first power amplifier circuit 701 and the second power amplifier circuit 702. Specifically, as shown in FIG10 , the first input end In1a of the first primary coupling line 7031a and the first input end In1b of the second primary coupling line 7031b are respectively used to receive the radio frequency input signal RF-in. The second input end In2a of the first primary coupling line 7031a and the second input end In2b of the second primary coupling line 7031b are respectively grounded. The first output end Out1 of the secondary coupling line 7032 is connected to the input end of the first power amplifier circuit 701, and the second output end Out2 of the secondary coupling line 7032 is connected to the input end of the second power amplifier circuit 702.

[0151] In this embodiment, balun 703 is an unbalanced-balanced balun that can convert an unbalanced RF input signal RF-in received from the input of a power amplifier or the output of a preceding single-ended power amplifier circuit into a balanced RF signal for reception and processing by a subsequent differential power amplifier circuit. When balun 703 serves as an input balun for a power amplifier, it is connected between the preceding circuit and the input of the differential power amplifier circuit. It can convert the single-ended signal output by the preceding circuit into a differential signal and match the output impedance of the preceding circuit with the input impedance of the differential power amplifier circuit, thereby reducing RF signal loss during transmission. When balun 703 serves as an interstage matching balun for a power amplifier, the power amplifier includes at least one single-ended amplifier circuit and at least one differential amplifier circuit, with the single-ended amplifier circuit preceding the differential amplifier circuit. The balun 703 is connected between two adjacent single-ended amplifier circuits and a differential amplifier circuit to convert the single-ended RF signal output by the previous single-ended amplifier circuit into a differential RF signal, and to match the output impedance of the previous single-ended amplifier circuit with the input impedance of the next differential amplifier circuit, thereby reducing the loss of the RF signal during transmission from the previous amplifier circuit to the next amplifier circuit.

[0152] In this embodiment, by splitting the primary coupling line 7031 into two parallel coupling lines 7031a and 7031b, the secondary coupling line 7032 can be sandwiched between the two primary coupling lines 7031a and 7031b, thereby improving the coupling degree of the balun without almost affecting the ratio of the balun inductance.

[0153] Optionally, the first primary coupling line 7031a, the second primary coupling line 7031b and the secondary coupling line 7032 can be set to a straight line, a broken line, an arc, a U shape, an L shape, etc. as needed to adapt to the layout of the first power amplifier circuit 701, the second power amplifier circuit 702 and other circuits.

[0154] In some embodiments, when the balun 703 has at least one bend, if the first and last sections of the balun 703 extend in different directions, the first primary coupling line, the second primary coupling line, and the secondary coupling line may intersect at the at least one bend, such that the overall lengths of the first primary coupling line, the second primary coupling line, and the secondary coupling line are substantially equal, thereby improving the coupling degree of the balun 703. The extension direction of the first section of the balun refers to the direction extending from the first input ports In1a, In1b and the first output port Out1 along each coupling line; the extension direction of the last section refers to the direction extending along each coupling line toward the second input ports In2a, In2b and the second output port Out2.

[0155] Specifically, the first primary coupling line, the second primary coupling line, and the secondary coupling line can be intersected by swapping the outermost coupling line with the outermost coupling line. For example, if, in the first section of the bend, the first primary coupling line is outside the secondary coupling line and the second primary coupling line is inside the secondary coupling line, then in the second section of the bend, the inner and outer relationships of the first and second primary coupling lines are swapped, with the first primary coupling line inside the secondary coupling line and the second primary coupling line outside the secondary coupling line.

[0156] For example, when a zigzag (including L-shaped) structure is employed, the balun 703 includes at least one bend. At this bend, the first primary coupling line 7031a includes a first segment and a second segment connected at a first angle, the secondary coupling line 7032 includes a third segment and a fourth segment connected at the first angle, and the second primary coupling line 7031b includes a fifth segment and a sixth segment connected at the first angle. When the balun 703 has an odd number of bends, at all or some of the odd-numbered bends, the first, third, and fifth segments are parallel to each other and their lengths increase in sequence; and the second, fourth, and sixth segments are parallel to each other and their lengths decrease in sequence. In this way, the sum of the first line segment and the second line segment, the sum of the third line segment and the fourth line segment, and the sum of the fifth line segment and the sixth line segment can be equal or approximately equal, so that the lengths of the first primary coupling line 7031a, the second primary coupling line 7031b and the secondary coupling line 7032 are equal or approximately equal, thereby increasing the coupling area of ​​the first primary coupling line 7031a, the second primary coupling line 7031b and the secondary coupling line 7032 and improving the coupling degree of the balun.

[0157] Exemplarily, as shown in FIG11 , the lengths of the first line segment, the second line segment, the third line segment, the fourth line segment, the fifth line segment, and the sixth line segment are recorded as S1, S2, S3, S4, S5, and S6, respectively, so that the difference in length between the third line segment and the first line segment (S3-S1), the difference in length between the fifth line segment and the third line segment (S5-S3), the difference in length between the second line segment and the fourth line segment (S2-S4), and the difference in length between the fourth line segment and the sixth line segment (S4-S6) are equal and are all the first value d, that is, S3-S1=S5-S3=S2-S4=S4-S6=d1, then S1+S2=S3+S4=S5+S6, so that the lengths of the first primary coupling line 7031a, the second primary coupling line 7031b, and the secondary coupling line 7032 are equal, thereby maximizing the coupling degree of the balun.

[0158] Optionally, the first angle is greater than or equal to 90°, so that the direction of current flowing through each coupling line does not change dramatically at the bend, thereby reducing RF signal loss and improving RF signal transmission efficiency. When the first angle is 90°, the gap between the third line segment and the first and fifth line segments is equal to the gap between the fourth line segment and the second and sixth line segments. As a result, the lengths of the first primary coupling line 7031a, the second primary coupling line 7031b, and the secondary coupling line 7032 are equal, thereby maximizing the coupling degree and impedance matching effect of the balun.

[0159] In some embodiments, as shown in FIG12 , when the balun 703 has at least two bending sections, if the first section and the last section of the balun 703 have the same extension direction, then at each bending section of the balun 703, the first primary coupling line, the second primary coupling line, and the secondary coupling line can remain parallel and not cross. At this time, the lengths of the coupling lines in the balun 703 are still equal or approximately equal, and the balun 703 still has a high degree of coupling.

[0160] In some embodiments, the secondary coupling line 7032 of the balun 703 includes a first secondary coupling line 7032a and a second secondary coupling line 7032b, the first secondary coupling line 7032a and the second secondary coupling line 7032b each having a first output end and a second output end, and the routing path of the first secondary coupling line 7032a from the first output end to the second output end and the routing path of the second secondary coupling line 7032b from the first output end to the second output end are both referred to as second routing paths, then the first routing path of the primary coupling line 7031 and the second routing paths of the first secondary coupling line 7032a and the second secondary coupling line 7032b follow each other.

[0161] In the embodiment of the present application, the primary coupling line 7031 is arranged between the first secondary coupling line 7032a and the second secondary coupling line 7032b, so that both the first secondary coupling line 7032a and the second secondary coupling line 7032b can be coupled with the primary coupling line 7031, thereby improving the coupling degree of the balun 703.

[0162] Optionally, the first secondary coupling line 7032a and the second secondary coupling line 7032b may be connected in series or in parallel.

[0163] In one embodiment, balun 703 serves as an output balun for a power amplifier, used for output impedance matching of the power amplifier. A first secondary coupling line 7032a and a second secondary coupling line 7032b can be connected in parallel. As shown in FIG13 , the first input terminal In1 of the primary coupling line 7031 is connected to the output terminal of the first power amplifier circuit 701, and the second input terminal In2 of the primary coupling line 7031 is connected to the output terminal of the second power amplifier circuit 702. The first output terminal Out1a of the first secondary coupling line 7032a and the first output terminal Out1b of the second secondary coupling line 7032b are both connected to the signal transmission terminal 704, and the second output terminal Out2a of the first secondary coupling line 7032a and the second output terminal Out2b of the second secondary coupling line 7032b are both grounded. In this embodiment, balun 703 is a balanced-unbalanced balun that can convert an input differential RF signal into a single-ended RF signal output and achieve impedance matching between the output terminal of the power amplifier (i.e., the output terminal of the first power amplifier circuit 701 and the output terminal of the second power amplifier circuit 702) and the input terminal of the subsequent circuit.

[0164] To maximize the coupling between the primary and secondary coupling lines, the first and second secondary coupling lines 7032a, 7032b can be made the same length as the primary coupling line 7031. In this case, since the first and second secondary coupling lines 7032a, 7032b are connected in parallel, their impact on inductance is minimal, and the ratio of the primary and secondary inductances of the balun 703 is approximately 1:1.

[0165] Optionally, the width of the first secondary coupling line 7032a and the width of the second secondary coupling line 7032b can be set slightly smaller than the width of the primary coupling line 7031, or kept approximately the same as the line width of the primary coupling line 7031, so as to improve the coupling degree of the balun 703.

[0166] As an embodiment, the balun 703 is used for input impedance matching or inter-stage impedance matching of a power amplifier. When the first secondary coupling line 7032a and the second secondary coupling line 7032b are connected in parallel, as shown in FIG14 , the first input terminal In1 of the primary coupling line 7031 is used to receive the input RF signal RF_in, and the first input terminal In2 of the primary coupling line 7031 is grounded. The first output terminal Out1a of the first secondary coupling line 7032a and the first output terminal Out1b of the second secondary coupling line 7032b are both connected to the input terminal of the first power amplifier circuit 701, and the second output terminal Out2a of the first secondary coupling line 7032a and the second output terminal Out2b of the second secondary coupling line 7032b are both connected to the input terminal of the second power amplifier circuit 702.

[0167] In this embodiment, the balun 703 is an unbalanced-balun, which can convert the input single-ended RF signal into a differential RF signal, and output the differential RF signal to a differential power amplifier circuit including a first power amplifier circuit and a second power amplifier circuit for power amplification. The balun 703 can also achieve impedance matching between the output end of the previous stage circuit and the input end of the differential power amplifier circuit (i.e., the input end of the first power amplifier circuit 701 and the input end of the second power amplifier circuit 702).

[0168] In order to maximize the coupling between the primary coupling line and the secondary coupling line, the lengths of the first secondary coupling line 7032a, the second secondary coupling line 7032b and the primary coupling line 7031 can be made the same. In this case, the ratio of the inductance between the primary and secondary of the balun 703 is approximately 1:1.

[0169] Optionally, the width of the first secondary coupling line 7032a and the width of the second secondary coupling line 7032b can be set to be slightly smaller than the width of the primary coupling line 7031, or kept approximately the same as the line width of the primary coupling line 7031, which can further improve the coupling degree of the balun 703.

[0170] As one embodiment, balun 703 is used for input impedance matching or inter-stage impedance matching of a power amplifier. When a first secondary coupling line 7032a and a second secondary coupling line 7032b are connected in series, as shown in FIG15 , a first input terminal In1 of primary coupling line 7031 is used to receive an input RF signal RF_in, and a first input terminal In2 of primary coupling line 7031 is grounded. A first output terminal Out1a of first secondary coupling line 7032a is connected to the input terminal of first power amplifier circuit 701, and a first output terminal Out1b of second secondary coupling line 7032b is connected to the input terminal of second power amplifier circuit 702. In this embodiment, balun 703 is an unbalanced-balanced balun. Its function can be referred to in the previous embodiment and will not be further described here.

[0171] Similarly, to maximize the coupling between the primary and secondary coupling lines, the lengths of the first and second secondary coupling lines 7032a, 7032b can be made the same as the length of the primary coupling line 7031. Since the series connection of the two secondary coupling lines is equivalent to increasing the length of the secondary coupling lines, the inductance of the secondary coupling lines is roughly doubled, thus achieving an inductance ratio of approximately 1:2.

[0172] Optionally, in each of the above embodiments, the first secondary coupling line 7032a, the second secondary coupling line 7032b and the primary coupling line 7031 can be set to a straight line, a broken line, an arc, a U shape, an L shape, etc. as needed to adapt to the layout of the first power amplifier circuit 701, the second power amplifier circuit 702 and other circuits.

[0173] In some embodiments, when the balun 703 has at least one bend, if the first and last sections of the balun 703 extend in different directions, the first secondary coupling line 7032a, the second secondary coupling line 7032b, and the primary coupling line 7031 may intersect at the at least one bend, such that the overall lengths of the first secondary coupling line 7032a, the second secondary coupling line 7032b, and the primary coupling line 7031 are substantially equal, thereby improving the coupling strength of the balun 703. The first section of the balun extends in a direction extending from the first input port In1 and the first output ports Out1a and Out1b along the coupling lines; the last section extends in a direction extending along the coupling lines toward the second input port In2 and the second output ports Out2a and Out2b.

[0174] Specifically, the first secondary coupling line 7032a, the second secondary coupling line 7032b, and the primary coupling line 7031 can be arranged so that the outermost coupling line and the outermost coupling line have their inside-outside relationship swapped. For example, if, in the first section of the bend, the first secondary coupling line is outside the primary coupling line and the second secondary coupling line is inside the primary coupling line, then in the second section of the bend, the inside-outside relationship of the first and second secondary coupling lines is swapped, with the first secondary coupling line inside the primary coupling line and the second secondary coupling line outside the primary coupling line.

[0175] For example, when a zigzag (including L-shaped) structure is employed, the balun 703 includes at least one bend. At this bend, the first secondary coupling line 7032a includes a seventh and eighth line segments connected at a second angle, the primary coupling line 7031 includes a ninth and tenth line segments connected at a second angle, and the second secondary coupling line 7032b includes an eleventh and twelfth line segments connected at a second angle. When the balun 703 has an odd number of bends, at all or some of the odd-numbered bends, the seventh, ninth, and eleventh line segments are parallel to each other and their lengths increase in sequence; and the eighth, tenth, and twelfth line segments are parallel to each other and their lengths decrease in sequence. In this way, the sum of the seventh line segment and the eighth line segment, the sum of the ninth line segment and the tenth line segment, and the sum of the eleventh line segment and the twelfth line segment can be equal or approximately equal, so that the lengths of the first secondary coupling line 7032a, the second secondary coupling line 7032b and the primary coupling line 7031 are equal or approximately equal, thereby increasing the coupling area of ​​the first secondary coupling line 7032a, the second secondary coupling line 7032b and the primary coupling line 7031 and improving the coupling degree of the balun.

[0176] Exemplarily, as shown in Figure 11, the lengths of the seventh line segment, the eighth line segment, the ninth line segment, the tenth line segment, the eleventh line segment, and the twelfth line segment are recorded as S7, S8, S9, S10, S11, and S12, respectively, so that the difference in length between the ninth line segment and the seventh line segment (S9-S7), the difference in length between the eleventh line segment and the ninth line segment (S11-S9), the difference in length between the eighth line segment and the tenth line segment (S8-S10), and the difference in length between the tenth line segment and the twelfth line segment (S10-S12) are equal and are all the second value d2, that is, S9-S7=S11-S9=S8-S10=S10-S12=d2, then S7+S8=S9+S10=S11+S12, so that the lengths of the first secondary coupling line 7032a, the second secondary coupling line 7032b and the primary coupling line 7031 are equal, thereby maximizing the coupling degree of the balun.

[0177] Optionally, the second angle is greater than or equal to 90°, so that the direction of current flowing through each coupling line does not change dramatically at the bend, thereby reducing RF signal loss and improving RF signal transmission efficiency. When the second angle is 90°, the gap between the ninth line segment and the seventh and eleventh line segments is equal to the gap between the tenth line segment and the eighth and twelfth line segments. The lengths of the first secondary coupling line 7032a, the second secondary coupling line 7032b, and the primary coupling line 7031 are equal, thereby maximizing the coupling degree and impedance matching effect of the balun.

[0178] It should be noted that in the embodiments of the present application, the coupling lines on the same metal layer are always separated from each other and are not connected. The intersections of the different coupling lines shown in the above figures are the intersections of the projections of the different coupling lines on a certain plane, rather than the intersections of the coupling lines themselves. In fact, near the intersection of any two coupling lines, one of the coupling lines can be jumped to the other metal layer through a conductive via, and then jumped back to the metal layer across the intersection to avoid physical connection between the two coupling lines.

[0179] In some embodiments, as shown in FIG12 , when the balun 703 has at least two bending sections, if the first section and the last section of the balun 703 have the same extension direction, then at each bending section of the balun 703, the first secondary coupling line 7032a, the second secondary coupling line 7032b, and the primary coupling line 7031 can remain parallel and not cross. At this time, the lengths of the coupling lines in the balun 703 are still equal or approximately equal, and the balun 703 still has a high degree of coupling.

[0180] In some embodiments, as shown in Figures 16 and 17, the primary coupling line 7031 includes a first primary coupling line 7031a and a second primary coupling line 7031b, and the secondary coupling line 7032 includes a first secondary coupling line 7032a and a second secondary coupling line 7032b. The first secondary coupling line 7032a and the second secondary coupling line 7032b are both disposed between the first primary coupling line 7031a and the second primary coupling line 7031b to enhance the coupling between the primary and secondary coupling lines.

[0181] As an embodiment, when the balun 703 serves as an output balun for a power amplifier, the first primary coupling line 7031a and the second primary coupling line 7031b can optionally be connected in series or in parallel between the output of the first power amplifier circuit 701 and the output of the second power amplifier circuit 702. For example, the first primary coupling line 7031a and the second primary coupling line 7031b can be connected in series between the output of the first power amplifier circuit 701 and the output of the second power amplifier circuit 702, as shown in FIG16(a); or they can be connected in parallel between the output of the first power amplifier circuit 701 and the output of the second power amplifier circuit 702, as shown in FIG16(b). In this case, the first secondary coupling line 7032a and the second secondary coupling line 7032b can be connected in parallel, with one end of the parallel secondary coupling line connected to the signal transmission end to transmit the amplified RF signal to the signal transmission end, and the other end connected to ground. In this embodiment, the balun 703 is a balanced-unbalanced balun. Its function can be referred to the relevant description of the previous embodiment and will not be repeated here.

[0182] As an embodiment, when the balun 703 serves as an input balun or an interstage matching balun for a power amplifier, the first secondary coupling line 7032a and the second secondary coupling line 7032b can optionally be connected in series or in parallel between the input of the first power amplifier circuit 701 and the input of the second power amplifier circuit 702. For example, the first secondary coupling line 7032a and the second secondary coupling line 7032b can be connected in series between the input of the first power amplifier circuit 701 and the input of the second power amplifier circuit 702, as shown in FIG17(a); or they can be connected in parallel between the input of the first power amplifier circuit 701 and the input of the second power amplifier circuit 702, as shown in FIG17(b). In this case, the first primary coupling line 7031a and the second primary coupling line 7031b can be connected in parallel, with one end of the parallel primary coupling line being used to receive a single-ended RF input signal and the other end being grounded. In this embodiment, the balun 703 is an unbalanced-balanced balun. Its function can be referred to the relevant description of the previous embodiment and will not be repeated here.

[0183] In at least one embodiment, the primary coupling line and the secondary coupling line can be respectively composed of multiple coupling lines connected in parallel, and the primary coupling lines and the secondary coupling lines can be staggered on the same metal layer to further increase the coupling area between the primary coupling line and the secondary coupling line, thereby improving the coupling degree of the transformer structure.

[0184] Optionally, when there are multiple primary and secondary coupling lines and they are located in the same plane, as shown in FIG18 , to ensure balance between the primary and secondary coupling lines, the coupling lines on both sides can be of the same type. For example, if both sides are primary coupling lines or both sides are secondary coupling lines, the difference between the number of primary and secondary coupling lines needs to be 1. Exemplarily, the transformer structure may include N primary coupling lines and M secondary coupling lines, with the N primary coupling lines and the M secondary coupling lines interleaved; where N and M are both positive integers, and N = M + 1 or N = M - 1. For example, when there is one more primary coupling line than secondary coupling line, i.e., N = M + 1, the primary coupling line and the secondary coupling line are interleaved in the order of primary → secondary ... → primary; when there is one more secondary coupling line than primary coupling line, i.e., N = M - 1, the primary coupling line and the secondary coupling line are interleaved in the order of secondary → primary ... → secondary. In this way, the coupling degree of the transformer structure can be improved while ensuring the balance of the transformer structure.

[0185] As an embodiment, the balun 703, the first power amplifier circuit 701, and the second power amplifier circuit 702 are all integrated into the chip. For example, the first primary coupling line 7031a, the second primary coupling line 7031b, the first secondary coupling line 7032a, and the second secondary coupling line 7032b can all be arranged in a straight line. Compared to a case where there is only one primary coupling line and only one secondary coupling line, the four coupling lines can increase the overall width of the balun, making the length and width of the chip closer when integrated into the chip. For example, the first power amplifier circuit 701 and the second power amplifier circuit 702 can be arranged on the same side of the linear balun 703. The first power amplifier circuit 701 and the second power amplifier circuit 702 each include a plurality of amplifier transistors connected in parallel, and the plurality of transistors in each power amplifier circuit can be arranged in an array along the extension direction of the coupling lines of the balun 703. At this time, when the first power amplifier circuit 701, the second power amplifier circuit 702 and the balun 703 are integrated in the chip, the difference between the length and width of the chip is small, which can prevent the chip from forming a long strip structure due to the balun being too long, reduce the risk of chip breakage, and make it more beautiful.

[0186] The amplifying transistors in the first power amplifier circuit 701 and the second power amplifier circuit 702 may be MOS (Metal-Oxide-Semiconductor) field effect transistors or HBT (Heterojunction Bipolar Transistor).

[0187] In the above embodiments, the first power amplifier circuit 701 and the second power amplifier circuit 702 can be integrated into the chip. Optionally, the balun 703 can be integrated into the chip together with the first power amplifier circuit 701 and the second power amplifier circuit 702, or can be provided outside the chip and connected to the chip.

[0188] An embodiment of the present application also provides a chip, as shown in Figure 19, the chip 19 includes at least one power amplifier, the power amplifier includes a first power amplifier circuit 191, a second power amplifier circuit 192 and a balun 193, the first power amplifier circuit 191 and the second power amplifier circuit 192 are respectively connected to the balun 193; wherein the balun 193 includes a primary coupling line 1931 and a secondary coupling line 1932, the primary coupling line 1931 includes a first input end and a second input end; the secondary coupling line 1932 includes a first output end and a second output end; wherein the first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is the routing path from the first input end to the second input end, and the second routing path is the routing path from the first output end to the second output end.

[0189] In the embodiment of the present application, since the paths of the primary coupling line 1931 and the secondary coupling line 1932 from the starting point to the end point follow each other, each segment of the primary coupling line 1931 can be coupled with the corresponding segment of the secondary coupling line 1932, and conversely, each segment of the secondary coupling line 1932 can also be coupled with the corresponding segment of the primary coupling line 1931, which has a better coupling degree than the structure shown in Figure 1.

[0190] In some embodiments, the balun 193 may adopt the same structure as the transformer structure 20 of any of the aforementioned embodiments. For example, it may be arranged in a straight line, a broken line, an arc, a U shape, an L shape, etc. For details, please refer to the description of the aforementioned embodiments, which will not be repeated here.

[0191] In some embodiments, the power amplifier may be implemented in the same or similar manner as the power amplifier 70 in any of the aforementioned embodiments, which will not be described in detail here.

[0192] In some embodiments, the first power amplifier circuit 191 includes a plurality of first amplifier transistors connected in parallel, and the second power amplifier circuit includes a plurality of second amplifier transistors connected in parallel; the primary coupling line and the secondary coupling line are both arranged in a straight line, and the plurality of first amplifier transistors and the plurality of second amplifier transistors are arranged side by side on one side of the balun along the extension direction of the primary coupling line and the secondary coupling line.

[0193] Optionally, the first amplifying transistor and the second amplifying transistor may be MOS (Metal-Oxide-Semiconductor) field effect transistors or HBT (Heterojunction Bipolar Transistor).

[0194] In one embodiment, the power amplifier may be a differential power amplifier circuit, wherein the first amplifying transistor and the second amplifying transistor are transistors of opposite types. For example, the first amplifying transistor may be a P-type MOS transistor / PNP-type HBT, and the second amplifying transistor may be an N-type MOS transistor / NPN-type HBT; or, the first amplifying transistor may be an N-type MOS transistor / NPN-type HBT, and the second amplifying transistor may be a P-type MOS transistor / PNP-type HBT.

[0195] In some embodiments, as shown in FIG20 , the chip 19 includes at least two power amplifiers 190, each of which is arranged side by side along a preset arrangement direction (x-direction), and the baluns in each power amplifier extend in the same direction (y-direction). The arrangement direction (x-direction) of each power amplifier is perpendicular to the extension direction (y-direction) of any balun. Thus, when the lengths of the primary and secondary coupling lines are long, by arranging multiple power amplifiers side by side, the length and width of the chip are made closer, thereby preventing the chip from forming a long strip structure due to an overly long balun, reducing the risk of chip breakage, and improving the appearance.

[0196] In some embodiments, as shown in Figures 21(a) and 21(b), the primary and secondary coupling lines are arranged in an L-shape; the first power amplifier circuit 191 includes a plurality of first amplifier transistors connected in parallel, arranged side by side along one side of the L-shape; the second power amplifier circuit 192 includes a plurality of second amplifier transistors connected in parallel, arranged side by side along the other side of the L-shape. Optionally, the first power amplifier circuit 191 and the second power amplifier circuit 192 can be arranged inside the balun, thereby rationally utilizing the space inside the L-shaped structure and making the overall chip layout more compact and smaller in area.

[0197] By configuring the primary and secondary coupling lines in an L-shape, the embodiment of the present application can extend the length of each coupling line compared to a straight line, thereby achieving greater inductance and being suitable for scenarios requiring greater inductance. Furthermore, the L-shaped balun can extend along the edge of the chip, leaving space inside the chip for other circuit layouts.

[0198] In some embodiments, the chip includes at least one metal layer. When the number of primary coupling lines and secondary coupling lines is one, the primary coupling line and the secondary coupling line can be located on the same metal layer. When the number of primary coupling lines or secondary coupling lines is greater than one, the at least one primary coupling line and the at least one secondary coupling line can be located on the same metal layer. Placing the at least one primary coupling line and the at least one secondary coupling line on the same layer can reduce the number of metal layers occupied by the balun, simplify the chip manufacturing process, and reduce costs.

[0199] In one embodiment, a chip includes a first metal layer and a second metal layer, each of which is provided with two primary coupling lines and one secondary coupling line. Taking a balun as an output balun for a power amplifier as an example, the two primary coupling lines on the same metal layer are connected to different power amplifier circuits and are mutually coupled with the secondary coupling lines located on the same metal layer. For example, the primary coupling lines include a first primary coupling line and a second primary coupling line provided on the first metal layer, and also include a third primary coupling line and a fourth primary coupling line provided on the second metal layer; the secondary coupling lines include a first secondary coupling line provided on the first metal layer and a second secondary coupling line provided on the second metal layer, wherein the first primary coupling line and the second primary coupling line are respectively coupled to the first secondary coupling line, and the third primary coupling line and the fourth primary coupling line are respectively coupled to the second secondary coupling line. Furthermore, the first and third primary coupling lines are both connected to the first power amplifier circuit, and the second and fourth primary coupling lines are both connected to the second power amplifier circuit. Optionally, the length of the first primary coupling line is the same as the length of the fourth primary coupling line, and the length of the second primary coupling line is the same as the length of the third primary coupling line. In this way, the sum of the first and third primary coupling lines is equal to the sum of the second and fourth primary coupling lines. That is, the total length of the primary coupling lines connected to the first power amplifier circuit is equal to the total length of the primary coupling lines connected to the second power amplifier circuit. Therefore, even if the first and second primary coupling lines on the same metal layer have different lengths, the power amplifier can still maintain good balance. In other words, when the balun has one or more bends, the two primary coupling lines and one secondary coupling line on the same metal layer do not need to cross at the bend to maintain the same length, thereby avoiding losses caused by coupling line crossing and improving the efficiency of the power amplifier.

[0200] In one embodiment, a chip includes a first metal layer and a second metal layer, each of which is provided with one primary coupling line and two secondary coupling lines. Taking a balun as an input balun for a power amplifier as an example, the two secondary coupling lines on the same metal layer are connected to different power amplifier circuits and are mutually coupled with the primary coupling line located on the same metal layer. For example, the secondary coupling lines include a first secondary coupling line and a second secondary coupling line provided on the first metal layer, and also include a third secondary coupling line and a fourth secondary coupling line provided on the second metal layer. The primary coupling lines include a first primary coupling line provided on the first metal layer and a second primary coupling line provided on the second metal layer, wherein the first secondary coupling line and the second secondary coupling line are respectively coupled to the first primary coupling line, and the third secondary coupling line and the fourth secondary coupling line are respectively coupled to the second primary coupling line. Furthermore, the first secondary coupling line and the third secondary coupling line are both connected to the first power amplifier circuit, and the second secondary coupling line and the fourth secondary coupling line are both connected to the second power amplifier circuit. Optionally, the length of the first secondary coupling line is the same as the length of the fourth secondary coupling line, and the length of the second secondary coupling line is the same as the length of the third secondary coupling line. In this way, the sum of the first and third secondary coupling lines is equal to the sum of the second and fourth secondary coupling lines. That is, the total length of the secondary coupling lines connected to the first power amplifier circuit is equal to the total length of the secondary coupling lines connected to the second power amplifier circuit. Therefore, even if the first and second secondary coupling lines on the same metal layer have different lengths, the power amplifier can still maintain good balance. In other words, when the balun has one or more bends, the two secondary coupling lines and one primary coupling line on the same metal layer do not need to cross at the bend to maintain the same length, thereby avoiding losses caused by coupling line crossing and improving the efficiency of the power amplifier.

[0201] An embodiment of the present application also provides an RF front-end module. As shown in FIG22 , the RF front-end module 22 includes a substrate 221, a power amplifier chip 222, and a balun 223. The power amplifier chip 222 and the balun 223 are both disposed on the substrate and can be connected via metal traces on the substrate. The balun 223 includes a primary coupling line 2231 and a secondary coupling line 2232. The primary coupling line 2231 includes a first input terminal In1 and a second input terminal In2; the secondary coupling line 2232 includes a first output terminal Out1 and a second output terminal Out2. The first routing path of the primary coupling line 2231 follows the second routing path of the secondary coupling line 2232. The first routing path is the routing path from the first input terminal In1 to the second input terminal In2, and the second routing path is the routing path from the first output terminal Out1 to the second output terminal Out2.

[0202] In the embodiment of the present application, since the paths of the primary coupling line 2231 and the secondary coupling line 2232 from the starting point to the end point follow each other, each segment of the primary coupling line can be coupled with the corresponding segment of the secondary coupling line, and vice versa, each segment of the secondary coupling line can also be coupled with the corresponding segment of the primary coupling line, which has a better coupling degree than the structure shown in Figure 1.

[0203] In some embodiments, the balun 223 may adopt the same structure as the transformer structure 20 of any of the aforementioned embodiments. For example, it may be arranged in a straight line, a broken line, an arc, a U shape, an L shape, etc. For details, please refer to the description of the aforementioned embodiments, which will not be repeated here.

[0204] Optionally, the balun 223 may be an output balun, an input balun, or an inter-stage matching balun of the power amplifier chip 222 .

[0205] In some embodiments, the power amplifier chip 222 integrates a first power amplifier circuit 2221 and a second power amplifier circuit 2222. The output of the first power amplifier circuit 2221 and the output of the second power amplifier circuit 2222 are respectively connected to the primary coupling line 2231 of the balun 223, and the secondary coupling line 2232 of the balun is connected to the signal transmission end. In this case, the balun 223 serves as the output balun of the power amplifier chip 222 and can convert the differential RF signal output by the power amplifier chip 222 into a single-ended RF signal for processing by subsequent circuits. It also matches the output impedance of the power amplifier chip with the input impedance of the subsequent circuit, thereby reducing RF signal loss during transmission.

[0206] In some embodiments, the power amplifier chip 222 integrates a first power amplifier circuit 2221 and a second power amplifier circuit 2222. The output of the first power amplifier circuit 2221 and the output of the second power amplifier circuit 2222 are respectively connected to the secondary coupling line 2232 of the balun. The primary coupling line 2231 of the balun is used to receive the RF input signal. In this case, the balun 223 can serve as an input balun or an inter-stage matching balun for the power amplifier chip 222. It can convert the single-ended RF signal received from the previous stage circuit into a differential RF signal to facilitate amplification by the differential power amplifier circuit in the power amplifier chip 222. It also matches the output impedance of the previous stage circuit with the input impedance of the subsequent stage differential power amplifier circuit, thereby reducing the loss of the RF signal during transmission.

[0207] Optionally, the overall shape of the balun 223 can be a bar, a broken line, a U-shape, a C-shape, an L-shape or other shapes to facilitate connection with the power amplifier chip 222, or to make the layout of the balun 223 and the power amplifier chip 222 more compact, thereby reducing the area occupied by the RF front-end module.

[0208] For example, when the required inductance is small, the balun 223 may be in a bar shape and disposed on one side of the power amplifier chip 222 .

[0209] For example, when the required inductance is large, the balun 223 can be C-shaped, U-shaped, L-shaped, or a broken line shape, and arranged around the power amplifier chip 222, that is, the power amplifier chip 222 can be arranged in the internal space formed by the C-shape, U-shape, or L-shape, so that the layout of the balun 223 and the power amplifier chip 222 is more compact.

[0210] For example, when the balun 223 serves as the output balun of the power amplifier chip 222, and other circuit devices need to be arranged between the output end of the power amplifier chip 222 and the subsequent circuit of the balun 223 (such as a radio frequency switch), the balun 223 can be in a zigzag or irregular line shape to avoid other circuit devices on the substrate.

[0211] In the embodiment of the present application, the shape and layout position of the balun 223 can be flexibly set to adapt to the layout of the power amplifier chip 222 and other circuits on the substrate, making the overall structure of the RF front-end module more compact and facilitating the miniaturization design of the RF front-end module.

[0212] In some embodiments, the substrate includes at least one metal layer. When the number of primary coupling lines and secondary coupling lines is one, the primary coupling line and the secondary coupling line can be located on the same metal layer. When the number of primary coupling lines or secondary coupling lines is greater than one, the at least one primary coupling line and the at least one secondary coupling line can be located on the same metal layer. Placing the at least one primary coupling line and the at least one secondary coupling line on the same layer can reduce the number of metal layers occupied by the balun, simplify the manufacturing process of the RF front-end module, and reduce costs.

[0213] In one embodiment, a substrate includes a first metal layer and a second metal layer, each of which is provided with two primary coupling lines and one secondary coupling line. Taking a balun as an output balun for a power amplifier as an example, the two primary coupling lines on the same metal layer are connected to different power amplifier circuits and are mutually coupled with the secondary coupling lines located on the same metal layer. For example, the primary coupling lines include a first primary coupling line and a second primary coupling line provided on the first metal layer, and also include a third primary coupling line and a fourth primary coupling line provided on the second metal layer; the secondary coupling lines include a first secondary coupling line provided on the first metal layer and a second secondary coupling line provided on the second metal layer, wherein the first primary coupling line and the second primary coupling line are respectively coupled to the first secondary coupling line, and the third primary coupling line and the fourth primary coupling line are respectively coupled to the second secondary coupling line. Furthermore, the first and third primary coupling lines are both connected to the first power amplifier circuit, and the second and fourth primary coupling lines are both connected to the second power amplifier circuit. Optionally, the length of the first primary coupling line is the same as the length of the fourth primary coupling line, and the length of the second primary coupling line is the same as the length of the third primary coupling line. In this way, the sum of the first and third primary coupling lines is equal to the sum of the second and fourth primary coupling lines. That is, the total length of the primary coupling lines connected to the first power amplifier circuit is equal to the total length of the primary coupling lines connected to the second power amplifier circuit. Therefore, even if the first and second primary coupling lines on the same metal layer have different lengths, the power amplifier can still maintain good balance. In other words, when the balun has one or more bends, the two primary coupling lines and one secondary coupling line on the same metal layer do not need to cross at the bend to maintain the same length, thereby avoiding losses caused by coupling line crossing and improving the efficiency of the power amplifier.

[0214] In one embodiment, a substrate includes a first metal layer and a second metal layer, each of which is provided with one primary coupling line and two secondary coupling lines. Taking a balun as an input balun for a power amplifier as an example, the two secondary coupling lines on the same metal layer are connected to different power amplifier circuits and are mutually coupled with the primary coupling line located on the same metal layer. For example, the secondary coupling lines include a first secondary coupling line and a second secondary coupling line provided on the first metal layer, and also include a third secondary coupling line and a fourth secondary coupling line provided on the second metal layer. The primary coupling lines include a first primary coupling line provided on the first metal layer and a second primary coupling line provided on the second metal layer, wherein the first secondary coupling line and the second secondary coupling line are respectively coupled to the first primary coupling line, and the third secondary coupling line and the fourth secondary coupling line are respectively coupled to the second primary coupling line. Furthermore, the first secondary coupling line and the third secondary coupling line are both connected to the first power amplifier circuit, and the second secondary coupling line and the fourth secondary coupling line are both connected to the second power amplifier circuit. Optionally, the length of the first secondary coupling line is the same as the length of the fourth secondary coupling line, and the length of the second secondary coupling line is the same as the length of the third secondary coupling line. In this way, the sum of the first and third secondary coupling lines is equal to the sum of the second and fourth secondary coupling lines. That is, the total length of the secondary coupling lines connected to the first power amplifier circuit is equal to the total length of the secondary coupling lines connected to the second power amplifier circuit. Therefore, even if the first and second secondary coupling lines on the same metal layer have different lengths, the power amplifier can still maintain good balance. In other words, when the balun has one or more bends, the two secondary coupling lines and one primary coupling line on the same metal layer do not need to cross at the bend to maintain the same length, thereby avoiding losses caused by coupling line crossing and improving the efficiency of the power amplifier.

[0215] In related art, the primary coil of a balun is typically a ring-wound, integrated coil. The differential RF signal is received / output by connecting its two ends to the two inputs / outputs of a differential power amplifier in a one-to-one correspondence. However, this integrated coil occupies a large area on the layout, and the enclosed space within the ring coil cannot be utilized, hindering the miniaturization of the RF front-end module. For example, due to the limited spacing between the two inputs / outputs of a differential power amplifier, if an integrated coil is used as the primary coil, in order to meet the required inductance, the primary coil can only be wound multiple times in a ring shape, thus occupying a large area and making it inconvenient for the layout of other circuit components in the power amplifier.

[0216] In order to solve this problem, the embodiments of the present application further provide a power amplifier, a chip and a radio frequency front-end module. By splitting the primary coil in the power amplifier into two independent coupling lines, the area occupied by the power amplifier is reduced, thereby facilitating the miniaturization design of the radio frequency front-end module. The following will be described in detail with reference to the accompanying drawings.

[0217] Please refer to Figures 23 and 24, which respectively illustrate a power amplifier according to an embodiment of the present application. As shown in Figures 23 and 24, the power amplifier 10 includes a first power amplifier circuit 11, a second power amplifier circuit 12, and a balun 13. The balun 13 includes a first coupling line 131, a second coupling line 132, and a third coupling line 133.

[0218] Among them, the first end of the first coupling line 131 is connected to the output end or the input end of the first power amplifier circuit 11, and the second end of the first coupling line 131 is connected to the first ground end; the first end of the second coupling line 132 is connected to the output end or the input end of the second power amplifier circuit, and the second end of the second coupling line 132 is connected to the second ground end; the first end of the third coupling line 133 is connected to the output end or the input end of the power amplifier, and the second end of the third coupling line 133 is connected to the third ground end.

[0219] For ease of description, in this embodiment of the present application, the coupling lines connected to the first power amplifier circuit and the second power amplifier circuit are referred to as primary coupling lines, and the other coupling lines are referred to as secondary coupling lines. That is, the first coupling line 131 and the second coupling line 132 are primary coupling lines of the balun 13, and the third coupling line is a secondary coupling line of the balun 13.

[0220] In an embodiment of the present application, the second end of the first coupling line 131 and the second end of the second coupling line 132 are both grounded, which is equivalent to forming an equivalent main-stage coupling line with a larger inductance in series. The first end of the first coupling line 131 and the first end of the second coupling line 132 are respectively connected to the corresponding power amplifier circuit, which is equivalent to connecting the two ends of the equivalent main-stage coupling line to a pair of differential power amplifier circuits, thereby forming a differential circuit architecture. Among them, the first ground end and the second ground end are different ground ends and can be grounded through different paths. For example, the first ground end and the second ground end can be grounded through different conductive vias; or, the first ground end and the second ground end can be grounded through different copper pillars or bonding wires. The present application does not limit the specific method of grounding, as long as the first ground end and the second ground end are different physical connection points and the paths of their grounding are different. Based on this, the two independent coupling lines are grounded separately through different ground ends, so that the two main-stage coupling lines can be independent of each other in physical space and can be connected in series in the circuit, thereby replacing the traditional integrated main-stage coupling line. Because the inductance of two primary coupling lines is superimposed after being connected in series, the inductance of a single primary coupling line can be reduced, thereby shortening the length of the single primary coupling line. As a result, the first coupling line 131 and the second coupling line 132 do not need to be fixedly configured as a multi-turn winding shape to increase the line length. The shape and position of each coupling line can be flexibly configured to accommodate the layout of other components, making the layout of the power amplifier more compact and facilitating the miniaturization of the RF front-end module. For example, as needed, the first coupling line 131 and the second coupling line 132 can be flexibly configured as a straight line, a broken line, an arc, a U-shape, or other shape, with the third coupling line 133 arranged to follow the first coupling line 131 and the second coupling line 132.

[0221] For example, when the first coupling line 131, the second coupling line 132 and the third coupling line 133 are in a straight line shape, the balun 13 as a whole presents a bar structure, the space occupied is very small, and there is no unusable closed space. At this time, the first power amplifier circuit 11 and the second power amplifier circuit 12 can be arranged on one side of the balun 13, making the overall layout of the power amplifier more compact.

[0222] Exemplarily, when the first coupling line 131, the second coupling line 132 and the third coupling line 133 are arc-shaped, L-shaped or U-shaped, since the arc-shaped, L-shaped and U-shaped shapes all have openings, at least part of the components in the first power amplifier circuit 11 and the second power amplifier circuit 12 can be set in the opening of the balun 13, so that the balun 13 surrounds / partially surrounds the first power amplifier circuit 11 and the second power amplifier circuit, avoiding wasting the space inside the opening, and making the overall layout of the power amplifier more compact.

[0223] In order to maintain good coupling, the first coupling line 131 , the second coupling line 132 and the third coupling line 133 may be close to each other and substantially parallel.

[0224] As an embodiment, the third coupling line 133 is disposed between the first coupling line 131 and the second coupling line 132, and is mutually coupled with the first coupling line 131 and the second coupling line 132. Thus, the secondary coupling line is sandwiched between the two primary coupling lines, giving the balun 13 good symmetry. Furthermore, the secondary coupling line located in the middle can couple with both primary coupling lines, thereby improving the coupling strength of the balun 13.

[0225] For example, the first coupling line 131 and the second coupling line 132 have the same length. In this case, the lengths of the first coupling line 131 and the second coupling line 132 can be shortened to half the length of a conventional coil. Alternatively, the length of the third coupling line 133 can be made the same as the lengths of the first coupling line 131 and the second coupling line 132 to further enhance the coupling between the primary coupling line and the secondary coupling line.

[0226] As an embodiment, as shown in FIG23 , a first end of a first coupled line 131 is connected to the output of the first power amplifier circuit 11, and a second end is connected to the first ground. A first end of a second coupled line 132 is connected to the output of the second power amplifier circuit 12, and a second end is connected to the second ground. Specifically, the first coupled line 131 and the second coupled line 132 are used to receive differential RF signals output by the first power amplifier circuit 11 and the second power amplifier circuit 12. A third coupled line 133 couples with the first coupled line 131 and the second coupled line 132 to generate a coupled RF signal RF_out. Since the first end of the third coupled line 133 is grounded, the third coupled line 133 outputs the coupled RF signal RF_out through the ungrounded first end. In this case, the balun 13 can be used to match the output impedance of the differential power amplifier circuit and achieve balanced-to-unbalanced conversion of the RF signal. Specifically, the balun 13 converts the balanced RF signal amplified and output by the first power amplifier circuit 11 and the second power amplifier circuit 12 into an unbalanced RF signal for output, for example, to a switching circuit at the back end of the power amplifier, which selectively outputs the unbalanced RF signal to the antenna port.

[0227] As another embodiment, as shown in FIG24 , the first end of the third coupling line 133 is used to receive the RF input signal RF_in, and the second end of the third coupling line 133 is grounded via the third ground terminal. The first coupling line 131 and the second coupling line 132 are respectively coupled to the third coupling line 133, and the first end of the first coupling line 131 is connected to the first power amplifier circuit 11, and the second end is grounded via the first ground terminal. The first end of the second coupling line 132 is connected to the second power amplifier circuit 12, and the second end is grounded via the second ground terminal, thereby outputting a differential RF signal to the first power amplifier circuit 11 and the second power amplifier circuit 12. In this case, the balun 13 can achieve unbalanced-to-balanced conversion of the RF signal, converting the single-ended (unbalanced) RF input signal RF_in from the previous stage circuit into a differential (balanced) RF signal, so that the differential RF signal can be power amplified by the first power amplifier circuit 11 and the second power amplifier circuit 702. The balun 13 can also be used for input impedance matching of the differential power amplifier circuit, for example, to achieve impedance matching between the output of the previous stage circuit and the input of the differential power amplifier circuit. Among them, the front-stage circuit of the balun 13 can be a radio frequency modulation circuit in the front stage of the power amplifier, or it can be other power amplifier circuits in the power amplifier located in the front stage of the first power amplifier circuit 11 and the second power amplifier circuit 12. This application does not limit this.

[0228] In some embodiments, as shown in Figures 25-26, the power amplifier 10 also includes a first matching capacitor C1 and a second matching capacitor C2, wherein the first matching capacitor C1 is connected in series between the output end / input end of the first power amplifier circuit 11 and the first end of the first coupling line 131, and the second matching capacitor C2 is connected in series between the output end / input end of the second power amplifier circuit 12 and the first end of the second coupling line 132; or, the first matching capacitor C1 is connected in series between the second end of the first coupling line 131 and the first ground end, and the second matching capacitor C2 is connected in series between the second end of the second coupling line 132 and the second ground end.

[0229] Generally speaking, the impedance in a circuit includes resistance, capacitance and inductance. The embodiment of the present application uses the first matching capacitor C1 and the second matching capacitor C2 to adjust the capacitance of the balun main stage so that it can participate in impedance matching together with the balun 13, thereby further improving the impedance matching degree between the differential power amplifier circuit and the previous stage circuit or the subsequent stage circuit, and improving the working efficiency of the power amplifier.

[0230] When a balun is used for output impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as one embodiment, as shown in FIG25 , a first matching capacitor C1 is connected in series between the output end of the first power amplifier circuit 11 and the first end of the first coupling line 131, and a second matching capacitor C2 is connected in series between the output end of the second power amplifier circuit 12 and the first end of the second coupling line 132. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the output ends of the first power amplifier circuit 11 and the second power amplifier circuit 12, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0231] When a balun is used for output impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as another embodiment, as shown in FIG26 , a first matching capacitor C1 is connected in series between the second end of the first coupling line 131 and the first ground terminal, and a second matching capacitor C2 is connected in series between the second end of the second coupling line 132 and the second ground terminal. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the ground terminals of the first coupling line 131 and the second coupling line 132, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0232] When a balun is used for input impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as one embodiment, as shown in FIG27 , a first matching capacitor C1 is connected in series between the input end of the first power amplifier circuit 11 and the first end of the first coupling line 131, and a second matching capacitor C2 is connected in series between the input end of the second power amplifier circuit 12 and the first end of the second coupling line 132. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the input ends of the first power amplifier circuit 11 and the second power amplifier circuit 12, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0233] When a balun is used for input impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as another embodiment, as shown in FIG28 , a first matching capacitor C1 is connected in series between the second end of the first coupling line 131 and the first ground terminal, and a second matching capacitor C2 is connected in series between the second end of the second coupling line 132 and the second ground terminal. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the ground terminals of the first coupling line 131 and the second coupling line 132, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0234] In some embodiments, as shown in Figures 29 and 30 , the power amplifier 10 further includes a third matching capacitor C3 connected in series between the output or input of the power amplifier and the first end of the third coupling line 133; alternatively, the third matching capacitor C3 is connected in series between the second end of the third coupling line 133 and the third ground terminal. Alternatively, the third matching capacitor C3 is connected in series between the two ends of the third coupling line. For example, the third coupling line can be divided into two equal sections, and these two sections are connected in series via the third matching capacitor C3.

[0235] The input end of the power amplifier is a port for receiving a radio frequency input signal RF_in, and the output end is a port for outputting a radio frequency signal RF_out.

[0236] When the balun 13 is used for output impedance matching of the power amplifier, the first end of the third coupling line 133 is used to output the RF signal RF_out generated by coupling, so the first end of the third coupling line 133 is connected to the output end of the power amplifier. At this time, the third matching capacitor C3 can be connected in series between the first end of the third coupling line 133 and the output end of the power amplifier as shown in Figure 29, or it can be connected in series between the second end of the third coupling line 133 and the third ground end as shown in Figure 30, and participate in the output impedance matching of the power amplifier together with the balun 13.

[0237] When the balun 13 is used for input impedance matching of the power amplifier, the first end of the third coupling line 133 is used to receive the RF input signal RF_in from the previous circuit, so the first end of the third coupling line 133 is connected to the input end of the power amplifier. At this time, the third matching capacitor C3 can be connected in series between the first end of the third coupling line 133 and the input end of the power amplifier, or it can be connected in series between the second end of the third coupling line 133 and the third ground end, and participate in the input impedance matching of the power amplifier together with the balun 13.

[0238] In the embodiment of the present application, the capacitive reactance of the secondary of the balun 13 is adjusted by the third matching capacitor C3 so that it participates in impedance matching together with the balun 13, thereby further improving the impedance matching degree between the differential power amplifier circuit and the preceding circuit or the following circuit, and improving the working efficiency of the power amplifier.

[0239] Optionally, when a third matching capacitor C3 is added to the secondary stage of the balun 13, a first matching capacitor C1 and a second matching capacitor C2 can be provided in the primary stage of the balun 13, thereby adjusting the capacitive reactance of both the primary and secondary stages of the balun. When impedance matching requirements can be met without adjusting the capacitive reactance of the primary stage of the balun, the first matching capacitor C1 and the second matching capacitor C2 can also be omitted, and this application does not limit this.

[0240] In some embodiments, as shown in Figures 31 and 32, the power amplifier 10 further includes a fourth matching capacitor C4 and a fifth matching capacitor C5. The fourth matching capacitor C4 is connected in series between the output or input of the power amplifier and the first end of the third coupling line; the fifth matching capacitor C5 is connected in series between the second end of the third coupling line and the third ground terminal. The input of the power amplifier is a port for receiving a radio frequency input signal RF_in, and the output is a port for outputting a radio frequency signal RF_out.

[0241] As an embodiment, when the balun 13 is used for output impedance matching of the power amplifier, the first end of the third coupling line 133 is used to output the RF signal RF_out generated by coupling, so the first end of the third coupling line 133 is connected to the output end of the power amplifier. At this time, as shown in Figure 31, the fourth matching capacitor C4 is connected in series between the first end of the third coupling line 133 and the output end of the power amplifier, and the fifth matching capacitor C5 is connected in series between the second end of the third coupling line 133 and the third ground end. The fourth matching capacitor C4 and the fifth matching capacitor C5 and the balun 13 jointly participate in the output impedance matching of the power amplifier.

[0242] As an embodiment, when the balun 13 is used for input impedance matching of the power amplifier, the first end of the third coupling line 133 is used to receive the RF input signal RF_in from the previous stage circuit, so the first end of the third coupling line 133 is connected to the input end of the power amplifier. At this time, as shown in Figure 32, the fourth matching capacitor C4 is connected in series between the first end of the third coupling line 133 and the input end of the power amplifier, and the fifth matching capacitor C5 is connected in series between the second end of the third coupling line 133 and the third ground end. The fourth matching capacitor C4 and the fifth matching capacitor C5 and the balun 13 jointly participate in the input impedance matching of the power amplifier.

[0243] Similar to Figures 29 and 30 , the fourth matching capacitor C4 and the fifth matching capacitor C5 in this embodiment are also used to adjust the capacitive reactance of the balun secondary, thereby jointly participating in the impedance matching of the power amplifier with the balun and improving the operating efficiency of the power amplifier. Compared with Figures 29 and 30 , the embodiment of the present application splits the third matching capacitor C3, which was originally only provided at one end of the third coupling line 133, into two matching capacitors C4 and C5, and provides the two matching capacitors C4 and C5 at both ends of the third coupling line 133, which can enhance the balance of the circuit.

[0244] As an implementation, to improve the balun's coupling lines, the lengths of the coupling lines are made approximately the same. Because the primary stage consists of two coupled lines in series, and the secondary stage consists of a single coupled line, the impedance of the primary stage is higher than that of the secondary stage. When balun 13 is used for output impedance matching, the secondary stage, acting as the output terminal, results in an output impedance lower than the input impedance, leading to a more pronounced circuit imbalance. However, replacing the third matching capacitor C3 with a fourth matching capacitor C4 and a fifth matching capacitor C5, symmetrically arranged at both ends of the third coupling line 133, can significantly improve the circuit's imbalance.

[0245] Optionally, to further improve circuit balance, the capacitance of the fourth matching capacitor C4 can be equal to the capacitance of the fifth matching capacitor C5. Assuming the required capacitance of the balun secondary is c, the capacitance of the fourth matching capacitor C4 and the fifth matching capacitor C5 can both be set to 2c. The equivalent capacitance of the two capacitors connected in series is the required capacitance c.

[0246] As an embodiment, when the fourth matching capacitor C4 is connected in series with the output of the power amplifier, if the output of the power amplifier is also provided with other circuits including capacitors, the fourth matching capacitor C4 can reuse or partially reuse the capacitors in the other circuits. For example, if the output of the power amplifier is also provided with a harmonic suppression circuit including an inductor and a capacitor, at least part of the capacitance of the fourth matching capacitor C4 can reuse the capacitors in the harmonic suppression circuit.

[0247] Similarly, when the secondary stage of the balun 13 is provided with the fourth matching capacitor C4 and the fifth matching capacitor C5, the primary stage of the balun 13 can be provided with the first matching capacitor C1 and the second matching capacitor C2, thereby adjusting the capacitive reactance of the primary and secondary stages of the balun simultaneously. When the capacitive reactance of the primary stage of the balun is not adjusted to meet the impedance matching requirements, the first matching capacitor C1 and the second matching capacitor C2 can also be omitted, and this application is not limited to this.

[0248] In each of the above embodiments, the balun 13 can be integrated into the chip or directly arranged on the substrate. The chip / substrate includes multiple metal layers, and the first coupling line 131, the second coupling line 132, and the third coupling line 133 can be located on the same metal layer or on different metal layers. For example, the first coupling line 131, the second coupling line 132, and the third coupling line 133 can be arranged in parallel with a small interval on the same metal layer. Since the thickness of the same metal layer is consistent, the line length, line width, and thickness of the first coupling line 131, the second coupling line 132, and the third coupling line 133 can be kept consistent, thereby making the ratio of the primary and secondary inductances of the balun more accurate. For example, when the first coupling line 131, the second coupling line 132, and the third coupling line 133 are located on different metal layers, in order to improve the coupling degree of the balun 13, the projections of the first coupling line 131, the second coupling line 132, and the third coupling line 133 on a certain metal layer can overlap with each other.

[0249] In some embodiments, as shown in Figures 33 and 34 , the balun 13 further includes a fourth coupling line 134 and a fifth coupling line 135, both of which are connected in parallel with the third coupling line 133. In this case, the balun 13 includes two primary coupling lines 131 and 132 and three secondary coupling lines 133, 134, and 135. To ensure the balance of the balun 13, the secondary coupling lines can be staggered with the primary coupling lines. Optionally, the secondary coupling lines and the primary coupling lines can be staggered on the same metal layer or on different metal layers.

[0250] For example, the first coupling line 131, the second coupling line 132, the third coupling line 133, the fourth coupling line 134, and the fifth coupling line 135 can be located on the same metal layer, and the first coupling line 131, the third coupling line 133, and the second coupling line 132 are sequentially arranged between the fourth coupling line 134 and the fifth coupling line 135. In this way, the primary and secondary coupling lines are staggered, maintaining a better balance in the circuit, and each primary coupling line can couple with two secondary coupling lines, thereby improving the coupling degree of the balun 13.

[0251] Exemplarily, as shown in Figure 35, the chip / substrate includes multiple metal layers, such as a first metal layer M1 and a second metal layer M2, wherein the first coupling line 131, the second coupling line 132 and the third coupling line 133 are located in the first metal layer M1, and the fourth coupling line 134 and the fifth coupling line 135 are located in the second metal layer M2; wherein the third coupling line 133, the fourth coupling line 134 and the fifth coupling line 135 can be connected in parallel through routing on the metal layer and metal vias passing through the metal layer.

[0252] In order to improve the coupling degree of the balun 13, the projection of the fourth coupling line 134 on the first metal layer is made to at least partially overlap with the first coupling line 131, and the projection of the fifth coupling line 135 on the first metal layer is made to at least partially overlap with the second coupling line 132. In this way, the first coupling line 131 can be coupled with the third metal line 133 located on the same metal layer and the fourth coupling line 134 located on another metal layer, and the second coupling line 132 can be coupled with the third metal line 133 located on the same metal layer and the fifth coupling line 135 located on another metal layer, thereby improving the coupling degree of the balun 13.

[0253] As an embodiment, as shown in FIG36 , the balun further includes a sixth coupling line 136. Sixth coupling line 136 is disposed on the second metal layer along with fourth coupling line 134 and fifth coupling line 135, and is sandwiched between fourth coupling line 134 and fifth coupling line 135. Sixth coupling line 136 is a primary coupling line, one end of which is connected to the output / input of the first power amplifier circuit, and the other end of which is connected to the output / input of the second power amplifier circuit. Thus, the three coupling lines arranged in the order of secondary, primary, and secondary on the second metal layer are symmetrical with the other three coupling lines arranged in the order of primary, secondary, and primary on the first metal layer, thereby improving the balance of the balun.

[0254] Optionally, the sixth coupling line is parallel to the third coupling line. For example, the projection of the sixth coupling line on the first metal layer may overlap or partially overlap with the third coupling line. Similarly, the projection of the fourth coupling line 134 on the first metal layer at least partially overlaps with the first coupling line 131, and the projection of the fifth coupling line 135 on the first metal layer at least partially overlaps with the second coupling line 132. In this way, each coupling line can couple not only with other coupling lines on the same layer, but also with coupling lines on other layers, effectively increasing the coupling area between the primary and secondary, and improving the coupling degree of the balun.

[0255] In one embodiment, the multiple metal layers of the substrate include a ground metal layer, and each ground terminal in the power amplifier 10 can be connected to the ground metal layer through a conductive via to achieve grounding. The first ground terminal and the second ground terminal can be connected to the ground metal layer of the substrate through different vias to achieve grounding, thereby allowing the two main-stage coupling lines to be physically independent of each other while also being connected in series in the circuit.

[0256] The embodiment of the present application also provides a chip, which may include a power amplifier as shown in any of the aforementioned embodiments. Based on the description of the aforementioned embodiment, the chip splits the main stage of the balun into two independent coupling lines, and grounds the two main stage coupling lines separately through different grounding terminals, so that the two main stage coupling lines can be independent of each other in physical space and can be connected in series in the circuit, thereby replacing the traditional integrated main stage coupling line. This method reduces the requirements for the line length of a single main stage coupling line, and there is no need to fix the main stage coupling line to a multi-turn winding shape in order to increase the line length, so that the shape and position of the coupling line can be flexibly set according to the layout requirements of other circuits, for example, it can be set to a straight line, a broken line, an arc, a U-shape or other shapes, and can also surround other circuits to make the layout more compact. In addition, this method shortens the line length of the coupling line, can be integrated in the chip, and occupies a smaller area than that set on the substrate, which is conducive to the miniaturization design of the RF front-end module.

[0257] The present application also provides an RF front-end module, as shown in Figures 37 and 38. The RF front-end module 14 includes a substrate 141 and a power amplifier as shown in any of the above embodiments. A power amplifier chip 142 is provided on the substrate 140, and the first power amplifier circuit 11 and the second power amplifier circuit 12 are integrated into the power amplifier chip 142. Optionally, the balun can be integrated into the power amplifier chip 142 as shown in Figure 37, or can be directly provided on the substrate 141. When the balun is integrated into the power amplifier chip 142, each ground terminal of the balun can be connected to different ground pins of the chip. Each pin of the chip (including the ground pin) is fixed to the top layer of the substrate through packaging. Some pins can be connected to other metal layers of the substrate through conductive vias. For example, the ground pin can be connected to the ground metal layer of the substrate through a conductive via to achieve grounding. When the balun is directly provided on the substrate 142, the first ground terminal and the second ground terminal can each be connected to the ground metal layer of the substrate 142 through different conductive vias to achieve grounding.

[0258] The embodiment of the present application splits the main stage of the balun into two independent coupling lines, and grounds the two main coupling lines separately through different ground terminals, so that the two main coupling lines can be physically independent of each other and can be connected in series in the circuit, thereby replacing the traditional integrated main coupling line. This method reduces the requirements for the line length of a single main coupling line, and does not need to be fixed to a multi-turn winding shape to increase the line length. Therefore, the shape and position of each coupling line can be flexibly set to adapt to the layout of other components, making the layout of the power amplifier more compact and facilitating the miniaturization design of the RF front-end module.

[0259] Generally speaking, a power amplifier includes one or more power amplifier circuits, each of which is composed of one or more transistors. In the related art, when a power amplifier includes multiple power amplifier circuits, for example, FIG39 is a schematic diagram of a power amplifier structure in the related art. The power amplifier 11 includes a power amplifier circuit 111 and a power amplifier circuit 112. The power amplifier circuit 111 and the power amplifier circuit 112 each include multiple transistors 100. All transistors 100 are aligned along one side of the power amplifier 11, thereby making the layout of the power amplifier circuits 11 and 12 neat and beautiful. However, this requires that at least one side of the power amplifier be sufficiently long, which increases the area occupied by the power amplifier.

[0260] In addition, when an impedance matching network is required on the input or output side of the power amplifier 11, for example, when a transformer 12 for impedance matching is required on the output side of the power amplifier 11, since the two ends of a coil in the transformer 12 need to be connected to the output ends of the power amplifier circuit 111 and the power amplifier circuit 112, respectively, and there are requirements for the length of the coil, and the output ends of the power amplifier circuit 111 and the power amplifier circuit 112 are relatively close, one coil of the transformer 12 is wound in a circle between the starting point and the end point with the output end of the other power amplifier circuit as the starting point to increase the coil length. The other coil needs to be coupled with the coil and connected to the subsequent circuit, so it is also wound in a circle, and the opening direction is opposite to that of the coil. This results in the overall shape of the transformer being a nearly closed ring, which requires a large area and further increases the volume of the RF front-end module.

[0261] In order to solve the problem of large power amplifier area and the resulting large volume of RF front-end module in related technologies, the embodiments of the present application further provide a power amplifier, a chip and a RF front-end module, which can improve the layout of the internal circuit of the power amplifier, reduce the occupied area of ​​the power amplifier, and further reduce the volume of the RF front-end module.

[0262] Please refer to Figure 40, which shows a schematic diagram of the structure of a power amplifier provided by an embodiment of the present application. As shown in Figure 40, the power amplifier 20 of this embodiment includes a first power amplifier circuit 21 and a second power amplifier circuit 22, wherein the first power amplifier circuit 21 includes a plurality of first amplifier transistors 211 connected in parallel, and the second power amplifier circuit 22 includes a plurality of second amplifier transistors 221 connected in parallel. The plurality of first amplifier transistors are arranged along a first direction X, and the plurality of second amplifier transistors are arranged along a second direction Y. The first direction X intersects the second direction Y, i.e., the plurality of first amplifier transistors 211 and the plurality of second amplifier transistors 221 are arranged in different directions.

[0263] As an implementation, the first direction X and the second direction Y may be perpendicular or substantially perpendicular to each other, which may make the layout of the plurality of first amplifying transistors 211 and the plurality of second amplifying transistors 221 more orderly and facilitate the layout of other circuits in the power amplifier.

[0264] As an embodiment, the first power amplifier circuit 21 and the second power amplifier circuit 22 can be integrated into the chip. In this case, the first direction X can be parallel to the first edge of the chip, and the second direction Y can be parallel to the second edge of the chip, wherein the first edge and the second edge are two intersecting edges, and the first edge is approximately perpendicular to the second edge. Therefore, the arrangement direction of the multiple first amplifier transistors 211 is also approximately perpendicular to the arrangement direction of the multiple second amplifier transistors 221.

[0265] Optionally, multiple first amplifying transistors 211 are arranged adjacent to the first edge of the chip, and multiple second amplifying transistors 221 are arranged adjacent to the second edge of the chip. In this way, it is possible to avoid dividing the chip into multiple scattered small areas, so that other areas in the chip are contiguous and larger areas, which facilitates the layout of other circuits in the chip.

[0266] Furthermore, one end of the region where the first power amplifier circuit 21 is located and one end of the region where the multiple second power amplifier circuits 22 are located are both near the same vertex of the chip. That is, the multiple first amplifier transistors 211 are arranged along the first edge of the chip, starting and ending near one vertex of the chip, and the multiple second amplifier transistors 221 are arranged along the second edge of the chip, starting and ending near the same vertex of the chip. This allows the layout area of ​​the first power amplifier circuit 21 and the second power amplifier circuit 22 to be more concentrated, facilitating simultaneous connection of subsequent circuits to the first power amplifier circuit 21 and the second power amplifier circuit 22. It also allows other areas of the chip to be more complete.

[0267] In the embodiment of the present application, the first amplifying transistor 211 and the second amplifying transistor 221 of the power amplifier are arranged in different directions, which reduces the length requirement of the power amplifier. The length of the power amplifier can even be shortened to half of that of the related art, thereby effectively reducing the area occupied by the power amplifier.

[0268] In the embodiments of the present application, the layout area for the first amplifying transistor is referred to as the first layout area, and the layout area for the second amplifying transistor is referred to as the second layout area. That is, multiple first amplifying transistors are disposed in the first layout area, and multiple second amplifying transistors are disposed in the second layout area. The first layout area and the second layout area are substantially rectangular in shape, with the multiple first amplifying transistors arranged along the long side of the first layout area, and the multiple second amplifying transistors arranged along the long side of the second layout area.

[0269] As an embodiment, as shown in FIG41 , the power amplifier further includes a balun 23. Optionally, the balun 23 can be connected to the output of the first power amplifier circuit and the output of the second power amplifier circuit to convert the output impedance of the first power amplifier circuit and the second power amplifier circuit to match the input impedance of the subsequent circuit. In this case, the balun can be disposed outside the first layout area and the second layout area.

[0270] The balun 23 can be connected to the input terminals of the first power amplifier circuit and the second power amplifier circuit to convert the input impedance of the first power amplifier circuit and the second power amplifier circuit to match the output impedance of the previous stage circuit. For example, the balun can be arranged inside the first layout area and the second layout area.

[0271] The inner side and the outer side of the first layout area are both areas outside the first layout area. Specifically, the outer side of the first layout area is adjacent to the output terminals of the plurality of first amplifying transistors; the inner side of the first layout area is adjacent to the input terminals of the plurality of first amplifying transistors.

[0272] Similarly, the inner side and the outer side of the second layout area are both other areas outside the second layout area. The outer side of the second layout area is the side adjacent to the output terminals of the plurality of second amplifying transistors; the inner side of the second layout area is the side adjacent to the input terminals of the plurality of second amplifying transistors.

[0273] In one embodiment, the connection point between the balun and the first power amplifier circuit is located adjacent to the midpoint of a side of the first layout area, and the connection point between the balun and the second power amplifier circuit is located adjacent to the midpoint of a side of the second layout area. The midpoint of a side of the first layout area may be the midpoint of a side where the input terminals of the plurality of first amplifier transistors are arranged, or the midpoint of a side where the output terminals of the plurality of first amplifier transistors are arranged. The midpoint of a side of the second layout area may be the midpoint of a side where the input terminals of the plurality of second amplifier transistors are arranged, or the midpoint of a side where the output terminals of the plurality of second amplifier transistors are arranged.

[0274] For example, when the balun is positioned outside the first and second layout areas, the connection point between the balun and the first power amplifier circuit is located near the midpoint of a side where the output terminals of the plurality of first amplifier transistors are arranged; the connection point between the balun and the second power amplifier circuit is located near the midpoint of a side where the output terminals of the plurality of second amplifier transistors are arranged. When the balun is positioned inside the first and second layout areas, the connection point between the balun and the first power amplifier circuit is located near the midpoint of a side where the input terminals of the plurality of first amplifier transistors are arranged; the connection point between the balun and the second power amplifier circuit is located near the midpoint of a side where the input terminals of the plurality of second amplifier transistors are arranged. By positioning the connection point of the balun near the midpoint between the output terminals and input terminals of the plurality of first and second amplifier transistors, the balance of the power amplifier can be improved.

[0275] In some embodiments, as shown in Figure 41, the power amplifier 20 also includes a balun 23, the balun 23 includes a primary coupling line 231 and a secondary coupling line 232 coupled to each other, the primary coupling line 231 and the secondary coupling line 232 each include a first segment and a second segment connected to each other, and the first segment extends along the first direction and the second segment extends along the second direction. Since the extension direction of the first segments of the main coupling line 231 and the secondary coupling line 232 are the same as the arrangement direction of the multiple first transistors 211 in the first power amplifier circuit 21, and the extension direction of the second segments of the main coupling line 231 and the secondary coupling line 232 are the same as the arrangement direction of the multiple second transistors 221 in the second power amplifier circuit 22, the main coupling line 231 and the secondary coupling line 232 of the balun 23 can be roughly arranged along the edge of the layout area of ​​the first power amplifier circuit 21 and the second power amplifier circuit 22, thereby making the layout of the balun 23 and the first power amplifier circuit 21 and the second power amplifier circuit 22 more compact, reducing the area occupied by the power amplifier 20.

[0276] As an embodiment, when the first power amplifier circuit 21 and the second power amplifier circuit 22 are integrated into a chip, the first segments of the primary coupling line 231 and the secondary coupling line 232 can be arranged adjacent to a first edge of the chip, and the second segments of the primary coupling line 231 and the secondary coupling line 232 can be arranged adjacent to a second edge of the chip. Because the first and second edges of the chip are substantially perpendicular, the balun is generally L-shaped. In this case, the first power amplifier circuit 21 and the second power amplifier circuit 22 can be arranged inside the L-shaped balun to make the layout of the first power amplifier circuit 21, the second power amplifier circuit 22, and the balun 23 more compact. Furthermore, the balun 23 is arranged outside the first power amplifier circuit 21 and the second power amplifier circuit 22, so that the primary coupling line 231 and the secondary coupling line 232 have sufficient length to meet the inductance required for impedance matching.

[0277] Optionally, the balun 23 can be integrated into the chip together with the first power amplifier circuit 21 and the second power amplifier circuit 22, or can be arranged outside the chip along the edge of the chip. For example, when the power amplifier is used in a Wi-Fi RF front-end module, since the operating frequency of the Wi-Fi RF front-end module is relatively high, the inductance requirement of the balun 23 is relatively low. Therefore, the balun 23 can be integrated into the chip to improve the integration of the RF front-end module and further reduce the size of the RF front-end module.

[0278] For example, when the power amplifier is applied to a Wi-Fi radio frequency front-end module, the operating frequency band of the power amplifier is 5.125 GHz to 7.125 GHz.

[0279] In some embodiments, the first power amplifier circuit 21 and the second power amplifier circuit 22 constitute a differential power amplifier circuit. The balun 23 can be connected to the output end of the differential power amplifier circuit to match the output impedance of the differential power amplifier circuit and achieve balanced-to-unbalanced conversion of the RF signal. That is, the balanced RF signal amplified and output by the first power amplifier circuit 21 and the second power amplifier circuit 22 is converted into an unbalanced RF signal for output, for example, to a switch at the back end of the power amplifier. Alternatively, the balun 23 can be connected to the input end of the differential power amplifier circuit to match the input impedance of the differential power amplifier circuit and achieve unbalanced-to-balanced conversion of the RF signal. That is, the unbalanced RF input signal is converted into a balanced RF signal and output to the differential power amplifier circuit, which then amplifies the balanced RF signal.

[0280] As shown in Figures 42 and 43, the balun 23 includes a first balanced end bal1, a second balanced end bal2 and an unbalanced end unb; the first balanced end bal1 is connected to the output end or the input end of the first power amplifier circuit 21; the second balanced end bal2 is connected to the output end or the input end of the second power amplifier circuit 22; the unbalanced end unb is used to receive the radio frequency input signal RF-in, or is connected to the output end Out of the power amplifier.

[0281] For ease of description, in the embodiments of the present application, the coupling line connected to the first balanced terminal bal1 or the second balanced terminal bal2 is referred to as a primary coupling line, and the coupling line connected to the unbalanced terminal unb is referred to as a secondary coupling line. Specifically, the primary coupling line 231 of the present application is connected to the first balanced terminal bal1 and the second balanced terminal bal2 for receiving or outputting balanced RF signals, while the secondary coupling line 232 is connected to the unbalanced terminal unb for receiving or outputting unbalanced RF signals. The end of the secondary coupling line 232 not connected to the unbalanced terminal unb may be grounded.

[0282] When the balun 23 is used for output impedance matching of a differential power amplifier circuit, as shown in FIG42 , the first balanced terminal bal1 is connected to the output terminal of the first power amplifier circuit 21, the second balanced terminal bal2 is connected to the output terminal of the second power amplifier circuit 22, and the primary coupling line 231 is connected between the first balanced terminal bal1 and the second balanced terminal bal2, thereby receiving the balanced RF signal output by the differential power amplifier circuit. The secondary coupling line 232 generates an unbalanced RF signal based on coupling with the primary coupling line 231 and transmits the unbalanced RF signal to the unbalanced terminal unb. The unbalanced terminal unb is connected to the output terminal Out of the power amplifier, thereby outputting the unbalanced RF output signal externally.

[0283] When the balun 23 is used for input impedance matching of a differential power amplifier circuit, as shown in FIG43 , the unbalanced terminal unb is used to receive an unbalanced RF input signal RF-in and transmit the unbalanced RF input signal RF-in to the secondary coupling line 232. The primary coupling line 231 is connected between the first balanced terminal bal1 and the second balanced terminal bal2, and generates a balanced RF signal based on coupling with the secondary coupling line 232. The first balanced terminal bal1 is connected to the input of the first power amplifier circuit 21, and the second balanced terminal bal2 is connected to the input of the second power amplifier circuit 22, thereby outputting the balanced RF signal to the differential power amplifier circuit for power amplification.

[0284] In some embodiments, as shown in Figures 44 and 45 , the primary coupling lines include a first coupling line cp1 and a second coupling line cp2, and the secondary coupling lines include a third coupling line cp3, where the third coupling line cp3 is arranged between the first coupling line cp1 and the second coupling line cp2. Thus, the three coupling lines are arranged alternately in the order of primary, secondary, and primary, with primary coupling lines arranged on both sides of the secondary coupling lines. This allows the secondary coupling lines to couple simultaneously with both primary coupling lines, thereby enhancing the coupling strength of the balun 23.

[0285] In one embodiment, the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 are provided on the same metal layer, and the third coupling line cp3 is sandwiched between the first coupling line cp1 and the second coupling line cp2, which are also located on the same metal layer. Providing all three coupling lines on the same metal layer can reduce the number of metal layers, lower costs, and facilitate production.

[0286] In one embodiment, the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 are disposed on different metal layers, and the metal layer on which the third coupling line cp3 resides is sandwiched between the metal layer on which the first coupling line cp1 resides and the metal layer on which the second coupling line cp2 resides. Placing the three coupling lines on different metal layers can make the layout of the power amplifier more compact on a planar surface, reducing the area of ​​the power amplifier. Optionally, the thickness of the metal layer on which the first coupling line cp1 resides is the same as the thickness of the metal layer on which the second coupling line cp2 resides, which can improve the balance of the balun and reduce RF signal loss.

[0287] When the balun 23 is integrated into the chip, the first metal layer can be one of the multiple metal layers of the chip. When the balun 23 is not integrated into the chip, the first metal layer can be one of the multiple metal layers of the substrate.

[0288] The longer the opposing portions of the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3, the larger the coupling area between the primary and secondary sides of the balun, and the higher the coupling degree of the balun. Optionally, the first end of the first coupling line cp1, the first end of the third coupling line cp3, and the first end of the second coupling line cp2 are arranged along the second direction Y; and the second end of the first coupling line cp1, the second end of the third coupling line cp3, and the second end of the second coupling line cp2 are arranged along the first direction X. In this way, the first ends of the coupling lines are arranged relative to each other, and the second ends of the coupling lines are also arranged relative to each other, which can increase the coupling area, improve the coupling degree of the balun, and enhance the balance of the balun.

[0289] For example, assuming that the first coupling line cp1 is located inside the third coupling line cp3, and the second coupling line cp2 is located outside the third coupling line cp3, then when the power amplifier is integrated into the chip, that is, the first power amplifier circuit 21, the second power amplifier circuit 22, and the balun 23 are all integrated into the chip, the chip includes a first edge and a second edge that are connected; the distances between the first segment of the first coupling line, the first segment of the third coupling line, and the first segment of the second coupling line and the first edge are successively decreasing; and the distances between the second segment of the first coupling line, the second segment of the third coupling line, and the second segment of the second coupling line and the first edge are successively increasing. Conversely, when the balun 23 is located outside the chip and arranged along the first and second edges of the chip, the distances between the first segment of the first coupling line, the first segment of the third coupling line, and the first segment of the second coupling line and the first edge are successively increasing, while the distances between the second segment of the first coupling line, the second segment of the third coupling line, and the second segment of the second coupling line and the first edge are successively decreasing.

[0290] Optionally, the third coupling line cp2 is spaced equal to the first coupling line cp1 and the second coupling line cp2, which can improve the balance of the balun.

[0291] As an embodiment, as shown in FIG44 , a first end of a first coupling line cp1 is connected to a first balanced terminal bal1, and a second end of the first coupling line is grounded. A first end of a second coupling line cp2 is grounded, and a second end of the second coupling line cp2 is connected to a second balanced terminal bal2. In particular, one of the first power amplifier circuit 21 and the second power amplifier circuit 22 is a P-type power amplifier circuit, and the other is an N-type power amplifier circuit. Accordingly, one of the first coupling line cp1 and the second coupling line cp2 is a P-type coupling line, and the other is an N-type coupling line.

[0292] In this embodiment, since the second end of the first coupling line cp1 and the first end of the second coupling line cp2 are both grounded, the first coupling line cp1 and the second coupling line cp2 are connected in series between the first balanced terminal bal1 and the second balanced terminal bal2, thereby enabling reception or transmission of balanced RF signals. One end of the third coupling line cp3 is grounded, and the other end is connected to the unbalanced terminal, thereby enabling output or reception of unbalanced RF signals.

[0293] The inductance of the coupled lines is substantially proportional to their lengths. For example, the sum of the lengths of the first coupled line cp1 and the second coupled line cp2 is twice the length of the third coupled line cp3. In this case, since the first coupled line cp1 and the second coupled line cp2 are connected in series, their lengths are effectively superimposed. Therefore, the balun 23 can achieve a primary-to-secondary inductance ratio of 2:1.

[0294] As an embodiment, as shown in FIG45 , the first end of the first coupled line cp1 and the first end of the second coupled line cp2 are both connected to the first balanced terminal bal1, and the second ends of the first coupled line cp1 and the second coupled line cp2 are both connected to the second balanced terminal bal1. In this case, the first coupled line cp1 and the second coupled line cp2 are connected in parallel between the first balanced terminal bal1 and the second balanced terminal bal2, thereby enabling the reception or transmission of balanced RF signals. A third coupled line cp3 has one end grounded and the other end connected to the unbalanced terminal, thereby enabling the output or reception of unbalanced RF signals.

[0295] The parallel connection of the first coupling line cp1 and the second coupling line cp2 effectively increases the line width of the coupling lines. The inductance of a coupling line primarily depends on its length, and the effect of line width on inductance is minimal. When the lengths of the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 are equal or very close, the balun 23 can achieve a primary-to-secondary inductance ratio of approximately 1:1.

[0296] As an embodiment, as shown in Figures 46 and 47, the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 are disposed on the same metal layer, such as the first metal layer. Furthermore, the lengths of the first segment of the first coupling line cp1, the first segment of the third coupling line cp3, and the first segment of the second coupling line cp2 decrease in sequence; while the lengths of the second segment of the first coupling line cp1, the second segment of the third coupling line cp3, and the second segment of the second coupling line cp2 increase in sequence. This allows the lengths of the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 to be equal or approximately equal, thereby increasing the coupling area between the primary and secondary coupling lines and improving the coupling degree of the balun.

[0297] Optionally, the first end of the first coupling line cp1, the first end of the third coupling line cp3, and the first end of the second coupling line cp2 are arranged along the second direction Y; the second end of the first coupling line cp1, the second end of the third coupling line cp3, and the second end of the second coupling line cp2 are arranged along the first direction X, and the first coupling line cp1, the second coupling line cp2, and the third coupling line cp3 are set to be equal in length. The third coupling line cp3 can be always located in the middle position, and the inner and outer relationship of the first coupling line cp1 and the second coupling line cp2 relative to the third coupling line cp3 can be changed in different sections to ensure that the lengths of the three are equal.

[0298] For example, as shown in FIG46 , the first segment of the first coupling line cp1 is located outside the third coupling line cp3 and is shorter than the first segment of the third coupling line cp3. The second segment is located inside the third coupling line cp3 and is longer than the second segment of the third coupling line cp3. As a result, the sum of the lengths of the first and second segments of the first coupling line cp1 is equal to or approximately equal to that of the third coupling line cp3. Similarly, the first segment of the second coupling line cp2 is located inside the first segment of the third coupling line cp3 and is longer than the first segment of the third coupling line cp3. The second segment is located outside the third coupling line cp3 and is shorter than the second segment of the third coupling line cp3. As a result, the sum of the lengths of the first and second segments of the second coupling line cp2 is equal to or approximately equal to that of the third coupling line cp3. Based on this embodiment, every point on the secondary coupling line can couple with the primary coupling line, maximizing the coupling degree of the balun.

[0299] It should be noted that the first, second, and third coupling lines cp1, cp2, and cp3 are always separated and disconnected from each other on the first metal layer. Figures 46 and 47 show the projections of the first, second, and third coupling lines cp1, cp2, and cp3 on the first metal layer, thus showing intersections. In practice, near the intersection of any two coupling lines, one of the coupling lines can be connected to another metal layer through a conductive via, then back to the first metal layer across the intersection, to avoid physical connection between the two coupling lines.

[0300] In some embodiments, as shown in Figure 48, the primary coupling line also includes a fourth coupling line cp4 and a fifth coupling line cp5, and the secondary coupling line also includes a sixth coupling line cp6; wherein, the fourth coupling line cp4 is connected in parallel with the first coupling line cp1, and the fifth coupling line cp5 is connected in parallel with the second coupling line cp2; the sixth coupling line cp6 is connected in parallel with the third coupling line cp3; the fourth coupling line cp4, the fifth coupling line cp5 and the sixth coupling line cp6 are all arranged in the second metal layer, and the sixth coupling line cp6 is arranged between the fourth coupling line cp4 and the fifth coupling line cp5.

[0301] When the balun 23 is integrated into the chip, the first metal layer and the second metal layer can be two adjacent layers among the multi-layer metal layers of the chip. When the balun 23 is not integrated into the chip, the first metal layer can be two adjacent layers among the multi-layer metal layers of the substrate.

[0302] In this embodiment, the coupling lines of the first metal layer and the second metal layer are arranged alternately in the order of primary, secondary, and primary, and the secondary coupling lines in each metal layer can be coupled with two primary coupling lines at the same time, thereby enhancing the coupling degree of the balun 23.

[0303] As an embodiment, as shown in Figure 48, the first end of the first coupling line cp1 and the first end of the fourth coupling line cp4 are both connected to the first balanced end bal1, and the second end of the first coupling line cp1 and the second end of the fourth coupling line cp4 are used for grounding; the first end of the second coupling line cp2 and the first end of the fifth coupling line cp5 are both connected to the second balanced end bal2, and the second end of the second coupling line cp2 and the second end of the fifth coupling line cp5 are used for grounding; the first end of the third coupling line cp3 and the first end of the sixth coupling line cp6 are both connected to the unbalanced end, and the second end of the third coupling line cp3 and the second end of the sixth coupling line cp6 are both used for grounding.

[0304] Among them, the first end of the first coupling line cp1 and the first end of the fourth coupling line cp4, the second end of the first coupling line cp1 and the second end of the fourth coupling line cp4, the first end of the second coupling line cp2 and the first end of the fifth coupling line cp5, the second end of the second coupling line cp2 and the second end of the fifth coupling line cp5, the first end of the third coupling line cp3 and the first end of the sixth coupling line cp6, and the second end of the third coupling line cp3 and the second end of the sixth coupling line cp6 can be respectively connected in parallel through conductive vias passing through the first metal layer and the second metal layer and the routing laid out on the first metal layer and the second metal layer.

[0305] Among them, one of the first power amplifier circuit 21 and the second power amplifier circuit 22 is a P-type power amplifier circuit, and the other is an N-type power amplifier circuit. Correspondingly, one of the first coupling line cp1 and the second coupling line cp2 is a P-coupling line, and the other is an N-coupling line; one of the fourth coupling line cp4 and the fifth coupling line cp5 is a P-coupling line, and the other is an N-coupling line.

[0306] Exemplarily, the first power amplifier circuit 21 is a P-type power amplifier circuit, the second power amplifier circuit 22 is an N-type power amplifier circuit, the first coupling line cp1 and the fourth coupling line cp4 connected to the first power amplifier circuit 21 are P coupling lines; the second coupling line cp2 and the fifth coupling line cp5 connected to the second power amplifier circuit 22 are N coupling lines.

[0307] Optionally, in order to reduce the loss of radio frequency signals, the coupling lines of each metal layer are parallel to each other and do not cross each other. For example, in the first metal layer, the first coupling line cp1, the second coupling line cp2 and the third coupling line cp3 are parallel to each other and do not cross each other; in the second metal layer, the fourth coupling line cp4, the fifth coupling line cp5 and the sixth coupling line cp6 are parallel to each other and do not cross each other. This can avoid the loss caused by the crossing of the coupling lines and improve the working efficiency of the power amplifier.

[0308] Optionally, to improve the balance and coupling of the balun, the lengths of the P coupling lines are equal to the lengths of the N coupling lines, i.e., the sum of the lengths of the first coupling line cp1 and the fourth coupling line cp4 is equal to the sum of the lengths of the second coupling line cp2 and the fifth coupling line cp5. To achieve equal lengths of the P coupling lines and the N coupling lines without crossing the coupling lines, the internal and external positional relationship of the P coupling lines and the N coupling lines on different metal layers can be changed so that the lengths of the P coupling lines and the lengths of the N coupling lines on the two metal layers are complementary.

[0309] Exemplarily, in the first metal layer, the first coupling line cp1 is located on the outside of the third coupling line cp3 and the second coupling line cp2, and its length is greater than that of the third coupling line cp3 and the second coupling line cp2; in the second metal layer, the fourth coupling line cp4 is located on the inside of the sixth coupling line cp6 and the fifth coupling line cp5, and its length is less than that of the sixth coupling line cp6 and the fifth coupling line cp5. Thus, the lengths of the first coupling line cp1 and the fourth coupling line cp4 can be complementary, and the lengths of the second coupling line cp2 and the fifth coupling line cp5 can be complementary, so that the length of the P coupling line is approximately equal to the length of the N coupling line, thereby improving the balance and coupling degree of the balun while avoiding the loss caused by the crossing of the coupling lines, thereby improving the working efficiency of the balun.

[0310] Furthermore, when the length of the primary coupling line is equal to the length of the secondary coupling line, the coupling degree of the balun is optimal, and the sum of the lengths of the third coupling line cp3 and the sixth coupling line cp6 can be made equal to the sum of the lengths of the first coupling line cp1 and the fourth coupling line cp4, further improving the coupling degree of the balun 23.

[0311] In one embodiment, the first metal layer is parallel to the second metal layer, the first coupling line cp1 is parallel to the fifth coupling line cp5 and has the same length; the second coupling line cp2 is parallel to the fourth coupling line cp4 and has the same length; and the third coupling line cp3 is parallel to the sixth coupling line cp6 and has the same length. For example, the projection of the first coupling line cp1 on the second metal layer overlaps with the fifth coupling line cp5; the projection of the second coupling line cp2 on the second metal layer overlaps with the fourth coupling line cp4; and the projection of the third coupling line cp3 on the second metal layer overlaps with the sixth coupling line cp6. In this way, the spacing between the primary and secondary coupling lines on the first metal layer is the same as the spacing between the primary and secondary coupling lines on the second metal layer, and the primary and secondary coupling lines on both metal layers can achieve an optimal coupling distance.

[0312] In some embodiments, as shown in Figures 49 and 50, the secondary coupling lines further include a seventh coupling line cp7 and an eighth coupling line cp8, each of which is connected in parallel with the third coupling line cp3. Optionally, the seventh coupling line cp7 and the eighth coupling line cp8 can be provided on the same metal layer as the third coupling line cp3, or on a different metal layer.

[0313] As an embodiment, as shown in Figure 49, the seventh coupling line cp7 and the eighth coupling line cp8 are both arranged in the first metal layer, and the first coupling line cp1, the third coupling line cp3, and the second coupling line cp2 are arranged in sequence between the seventh coupling line cp7 and the eighth coupling line cp8; in this way, the primary and secondary coupling lines on the first metal layer are arranged in an staggered manner, specifically, the 5 coupling lines are arranged in the order of secondary, primary, secondary, primary, and secondary, and each primary coupling line can be coupled with two secondary coupling lines, increasing the coupling area between the primary and secondary coupling lines, thereby improving the coupling degree of the balun.

[0314] As another embodiment, as shown in FIG50 , the seventh coupling line cp7 and the eighth coupling line cp8 are disposed in the third metal layer. The seventh coupling line cp7 is parallel to the first coupling line cp1, and its projection on the first metal layer at least partially overlaps with the first coupling line cp1. The eighth coupling line cp8 is parallel to the second coupling line, and its projection on the first metal layer at least partially overlaps with the second coupling line cp2. The third metal layer and the first metal layer are different metal layers. Due to the small distance between the metal layers, the layout of this embodiment enables the seventh coupling line cp7 to couple with the first coupling line cp1, and the eighth coupling line cp8 to couple with the second coupling line cp2. This also increases the coupling area between the primary and secondary coupling lines, thereby improving the coupling degree of the balun.

[0315] Optionally, when the seventh coupling line cp7 and the eighth coupling line cp8 are provided in the third metal layer, the third metal layer may further be provided with a ninth coupling line cp9, which is a primary coupling line, the first end of which is connected to the first end of the first coupling line cp1, and the second end of which is connected to the second end of the second coupling line cp2. Based on this, a primary coupling line is further provided between the two secondary coupling lines of the third metal layer, forming a secondary, primary, and secondary layout on the third metal layer, thereby improving the balance of the balun. Moreover, the two secondary coupling lines cp7 and cp8 of the third metal layer can not only couple with the corresponding primary coupling lines of the first metal layer, but can also couple with the primary coupling line cp9 also located in the third metal layer, thereby further improving the coupling degree of the balun.

[0316] In some embodiments, as shown in FIG51 , the power amplifier further includes a bias module 24, which is disposed in a fourth layout region and is respectively connected to the first power amplifier circuit 21 and the second power amplifier circuit 22. The fourth layout region refers to a region between one end of the first layout region and the second edge, and between one end of the second layout region and the first edge.

[0317] The first power amplifier circuit 21 and the second power amplifier circuit 22 require a certain bias voltage when working. The bias module 24 can provide appropriate bias voltage for the first power amplifier circuit 21 and the second power amplifier circuit 22 so that the power amplifiers can work normally.

[0318] Exemplarily, the bias module 24 is integrated into the same chip as the first power amplifier circuit 21 and the second power amplifier circuit 22. Because the first layout area where the first power amplifier circuit 21 is located and the second layout area where the second power amplifier circuit is located both have a certain width, a small blank area, namely the fourth layout area, exists between the end of the first layout area near the second edge, the end of the second layout area near the first edge, and the junction between the first and second edges. Placing the bias module 24 in the fourth layout area not only facilitates connection with the first and second power amplifier circuits 21, 22, but also makes the chip layout more compact, improves the integration of the power amplifier, and reduces the size of the power amplifier and RF front-end module.

[0319] As shown in FIG52 , the bias module 24 includes a first bias circuit 241 and a second bias circuit 242. The first bias circuit is connected to the first power amplifier circuit 21 and disposed between the first power amplifier circuit 21 and the second edge of the chip. The second bias circuit 242 is connected to the second power amplifier circuit 22 and disposed between the second power amplifier circuit 242 and the first edge of the chip. Independent bias circuits 241 and 242 provide bias for the first power amplifier circuit 21 and the second power amplifier circuit 22, respectively, thereby reducing interference between the first power amplifier circuit 21 and the second power amplifier circuit 22. Furthermore, the two bias circuits 241 and 242 are disposed along the arrangement direction of the transistors in the corresponding power amplifier circuits 21 and 22, respectively, thereby improving the balance of the power amplifiers.

[0320] As an embodiment, when the first power amplifier circuit 21, the second power amplifier circuit 22, the balun 23, and the bias module 24 are integrated into the same chip, the bias module 24 can be disposed inside the balun 23, between the first power amplifier circuit 21, the second power amplifier circuit 22, and the balun 23. This facilitates the connection between the bias module 24 and the first power amplifier circuit 21, the second power amplifier circuit 22, and the balun 23, and also facilitates the layout of the coupling lines in the balun 23.

[0321] In some embodiments, the power amplifier further includes at least one output filter circuit, which is respectively connected to the output end of the first power amplifier circuit 21 and the output end of the second power amplifier circuit 22, and is used to suppress harmonics carried in the radio frequency signals output by the first power amplifier circuit 21 and the second power amplifier circuit 22, for example, to suppress second harmonics or third harmonics.

[0322] As an implementation method, the output filter circuit is also arranged in the fourth layout area, which is convenient for connection and can reasonably utilize the gaps between the first layout area, the second layout area and the first edge, the second edge, making the overall layout of the power amplifier more compact.

[0323] In some embodiments, the power amplifier further includes a first feeding terminal and a second feeding terminal, wherein the first feeding terminal is connected to the first power amplifier circuit and is configured to receive a first supply voltage Vcc1 and transmit the first supply voltage Vcc1 to the first power amplifier circuit to power the first power amplifier circuit. The second feeding terminal is connected to the second power amplifier circuit and is configured to receive a second supply voltage Vcc2 and transmit the second supply voltage Vcc2 to the second power amplifier circuit to power the second power amplifier circuit. The voltage values ​​of the first supply voltage Vcc1 and the second supply voltage Vcc2 can be equal. Feeding the first power amplifier circuit and the second power amplifier circuit through different feeding terminals can improve isolation and prevent interference between the supply voltages of the two circuits.

[0324] As an embodiment, the first and second feed terminals are also arranged in the fourth layout area. Compared to the traditional method of placing the feed terminals at the edge of the chip, this embodiment places the feed terminals in the fourth layout area inside the chip. This can shorten the feed path and rationally utilize the gaps between the first and second layout areas and the first and second edges, making the overall layout of the power amplifier more compact. Since two feed terminals are removed from the chip edge, the layout of the chip's other ports can be more flexible.

[0325] In some embodiments, the fourth layout area may further be provided with some passive components that need to be connected to the first power amplifier circuit and the second power amplifier circuit at the same time, and this application does not impose any restrictions on this.

[0326] In some embodiments, as shown in Figures 53-56, the power amplifier further includes a third power amplifier circuit 25. The third power amplifier circuit serves as a preamplifier circuit for the first and second power amplifier circuits. Specifically, the output of the third power amplifier circuit is connected to the input of the first and second power amplifier circuits, respectively.

[0327] The third power amplifier circuit includes a plurality of third amplifier transistors. Optionally, the third power amplifier circuit 25 can be a single-ended power amplifier circuit or a differential power amplifier circuit. When the third power amplifier circuit 25 is a single-ended power amplifier circuit, the third amplifier transistors are connected in parallel. When the third power amplifier circuit 25 is a differential power amplifier circuit, the plurality of third amplifier transistors can be divided into two groups, each group including one third amplifier transistor or multiple third amplifier transistors connected in parallel.

[0328] As an embodiment, the plurality of third amplifying transistors may be arranged along the first direction or along the second direction. In this case, the plurality of third amplifying transistors are arranged in a strip shape, and may be parallel to the plurality of first amplifying transistors or parallel to the plurality of second amplifying transistors, making the layout of the power amplifier more neat and compact.

[0329] As an embodiment, the plurality of third amplifying transistors can be divided into two groups, with some of the third amplifying transistors arranged along the first direction and others along the second direction. For example, when the third power amplifier circuit 25 is a differential power amplifier circuit, the plurality of third amplifying transistors in the same group connected in parallel can be arranged in the same direction. In this case, the plurality of third amplifying transistors are arranged in a roughly L-shaped arrangement, consistent with the layout of the first and second power amplifier circuits, making the layout of the internal circuits of the power amplifier more compact and aesthetically pleasing.

[0330] In some embodiments, as shown in Figures 53-56, the power amplifier further includes an inter-stage matching circuit 26, which is disposed between the third power amplifier circuit 25 and the first and second power amplifier circuits 21, 22. The inter-stage matching circuit 26 is configured to match the output impedance of the third power amplifier circuit 25 with the input impedance of the first and second power amplifier circuits 21, 22, thereby reducing the loss of the RF signal during transmission from the third power amplifier circuit 25 to the first and second power amplifier circuits 21, 22. Specifically, the input end of the inter-stage matching circuit 26 is connected to the output end of the third power amplifier circuit 25, and the output end of the inter-stage matching circuit 26 is connected to the input end of the first and second power amplifier circuits 21, 22.

[0331] The inter-stage matching circuit 26 is disposed in an inter-stage layout region, which includes a first side 261 away from the first power amplifier circuit and a second side 262 away from the second power amplifier circuit. Optionally, the third amplifying transistors may be arranged in a direction parallel to the first side 261 of the inter-stage layout region; or in a direction parallel to the second side 262 of the inter-stage layout region; or partially in a direction parallel to the first side 261 of the inter-stage layout region and partially in a direction parallel to the second side 262 of the inter-stage layout region.

[0332] Exemplarily, when the third power amplifier circuit 25 is a differential power amplifier circuit, as shown in Figure 56, one of the two groups of third amplifier transistors can be arranged in a direction parallel to the first side 261 of the inter-stage layout area, and the other group can be arranged in a direction parallel to the second side 262 of the inter-stage layout area.

[0333] In one embodiment, the inter-stage matching circuit 26 includes a transformer, which includes an input coupling line and an output coupling line coupled to each other. Optionally, the input coupling line and the output coupling line can be wound into coils, for example, the input coupling line and the output coupling line are both wound along the edge of the inter-stage layout area.

[0334] Optionally, the input coupling line and the output coupling line can also be similar to the primary and secondary coupling lines of the balun, and have an L-shaped routing. For example, as shown in Figure 56, the input coupling line and the output coupling line each include a third segment and a fourth segment connected to each other, and the third segment extends along the first direction, and the fourth segment extends along the second direction. In this way, the layout area of ​​the inter-stage matching circuit is roughly the same as the layout area shape of the differential power amplifier circuit composed of the first power amplifier circuit 21 and the second power amplifier circuit 22. The positions of the two output ends of the inter-stage matching circuit can be close to the input end of the first power amplifier circuit 21 and the input end of the second power amplifier circuit 22, respectively, which facilitates routing and has a very compact layout.

[0335] Optionally, the input coupling line and the output coupling line may be located in the same metal layer or in at least two adjacent metal layers. When the input coupling line and the output coupling line are located in different metal layers, the coupling degree of the transformer can be improved by making their projections on any metal layer at least partially overlap.

[0336] In one embodiment, when the third power amplifier circuit 25 is a single-ended power amplifier circuit, the third power amplifier circuit has a single output terminal. In this case, one end of the transformer's input coupling line is connected to the output terminal of the third power amplifier circuit, and the other end is grounded. The two ends of the transformer's output coupling line are connected one-to-one with the input terminal of the first power amplifier circuit 21 and the input terminal of the second power amplifier circuit 22, respectively. In this embodiment, the transformer not only performs inter-stage impedance matching but also converts the unbalanced RF signal output by the third power amplifier circuit 25 into a balanced RF signal, thereby achieving unbalanced-to-balanced conversion of the RF signal. In this case, the transformer can also be referred to as an inter-stage matching balun.

[0337] As an embodiment, when the third power amplifier circuit 25 is a differential power amplifier circuit, the third power amplifier circuit has two output terminals. At this time, the two ends of the input coupling line of the transformer are respectively connected one-to-one with the two output terminals of the third power amplifier circuit 25, and the two ends of the output coupling line of the transformer are respectively connected one-to-one with the input terminal of the first power amplifier circuit 21 and the input terminal of the second power amplifier circuit 22.

[0338] Except for the location of the layout area, other implementations of the transformer may be the same as or similar to the implementation of the balun 23. For details, please refer to the previous description of the balun 23, which will not be repeated here.

[0339] In some embodiments, when the third power amplifier circuit 25 is a differential power amplifier circuit, the inter-stage matching circuit may also be implemented not through a transformer, but through at least one passive device with inductive reactance or capacitive reactance, such as an inductor, a capacitor, and a combination thereof. This application does not impose any restrictions on this.

[0340] In some embodiments, in addition to the balun 23, the power amplifier 20 further includes other matching circuits or components that participate in impedance matching of the power amplifier 20 together with the balun 23. The following description takes a balun including a first coupling line cp1, a second coupling line cp2, and a third coupling line cp3 as an example.

[0341] As an embodiment, as shown in Figure 57, the power amplifier 20 also includes a first matching capacitor C1 and a second matching capacitor C2, wherein the first matching capacitor C1 is connected in series between the output end / input end of the first power amplifier circuit 21 and the first end of the first coupling line cp1, and the second matching capacitor C2 is connected in series between the output end / input end of the second power amplifier circuit 22 and the first end of the second coupling line cp2; or, the first matching capacitor C1 is connected in series between the second end of the first coupling line cp1 and the first ground end, and the second matching capacitor C2 is connected in series between the second end of the second coupling line cp2 and the second ground end.

[0342] Generally speaking, the impedance in a circuit includes resistance, capacitance and inductance. The embodiment of the present application uses the first matching capacitor C1 and the second matching capacitor C2 to adjust the capacitance of the balun main stage so that it can participate in impedance matching together with the balun 23, thereby further improving the impedance matching degree between the differential power amplifier circuit and the previous stage circuit or the subsequent stage circuit, and improving the working efficiency of the power amplifier.

[0343] When a balun is used for output impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as one embodiment, as shown in FIG57 , a first matching capacitor C1 is connected in series between the output end of the first power amplifier circuit 21 and the first end of the first coupling line cp1, and a second matching capacitor C2 is connected in series between the output end of the second power amplifier circuit 22 and the first end of the second coupling line cp2. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the output ends of the first power amplifier circuit 21 and the second power amplifier circuit 22, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0344] When the balun 23 is used for output impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as another embodiment, as shown in FIG58 , a first matching capacitor C1 is connected in series between the second end of the first coupling line cp1 and the first ground terminal, and a second matching capacitor C2 is connected in series between the second end of the second coupling line cp2 and the second ground terminal. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the ground terminals of the first coupling line cp1 and the second coupling line cp2, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby improving the operating efficiency of the power amplifier.

[0345] When a balun is used for input impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as one embodiment, a first matching capacitor C1 is connected in series between the input end of the first power amplifier circuit 21 and the first end of the first coupling line cp1, and a second matching capacitor C2 is connected in series between the input end of the second power amplifier circuit 22 and the first end of the second coupling line cp2. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the input ends of the first power amplifier circuit 21 and the second power amplifier circuit 22, thereby providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0346] When a balun is used for input impedance matching of a differential power amplifier circuit composed of a first power amplifier circuit and a second power amplifier circuit, as another embodiment, a first matching capacitor C1 is connected in series between the second end of the first coupling line cp1 and the first ground terminal, and a second matching capacitor C2 is connected in series between the second end of the second coupling line cp2 and the second ground terminal. In this case, the first matching capacitor C1 and the second matching capacitor C2 are respectively disposed at the ground terminals of the first coupling line cp1 and the second coupling line cp2, providing good symmetry, improving circuit balance, and simultaneously participating in impedance matching, thereby enhancing the operating efficiency of the power amplifier.

[0347] In some embodiments, as shown in Figures 59 and 60, the power amplifier 10 further includes a third matching capacitor C3, which is connected in series between the output or input terminal of the power amplifier and the first end of the third coupling line cp3; or the third matching capacitor C3 is connected in series between the second end of the third coupling line cp3 and the third ground terminal. The input terminal of the power amplifier is a port for receiving a radio frequency input signal RF_in, and the output terminal is a port for outputting a radio frequency signal RF_out.

[0348] When the balun 23 is used for output impedance matching of the power amplifier, the first end of the third coupling line cp3 is used to output the RF signal RF_out generated by coupling, so the first end of the third coupling line cp3 is connected to the output end out of the power amplifier. At this time, the third matching capacitor C3 can be connected in series between the first end of the third coupling line cp3 and the output end of the power amplifier as shown in Figure 59, or it can be connected in series between the second end of the third coupling line cp3 and the third ground end as shown in Figure 60, and participate in the output impedance matching of the power amplifier together with the balun 23.

[0349] When the balun 23 is used for input impedance matching of the power amplifier, the first end of the third coupling line cp3 is used to receive the RF input signal RF_in from the previous stage circuit, so the first end of the third coupling line cp3 is connected to the input end of the power amplifier. At this time, the third matching capacitor C3 can be connected in series between the first end of the third coupling line cp3 and the input end of the power amplifier, or it can be connected in series between the second end of the third coupling line cp3 and the third ground end, and participate in the input impedance matching of the power amplifier together with the balun 23.

[0350] In the embodiment of the present application, the capacitive reactance of the secondary of the balun 23 is adjusted by the third matching capacitor C3 so that it participates in impedance matching together with the balun 23, thereby further improving the impedance matching degree between the differential power amplifier circuit and the preceding circuit or the following circuit, and improving the working efficiency of the power amplifier.

[0351] Optionally, when a third matching capacitor C3 is added to the secondary stage of the balun 23, a first matching capacitor C1 and a second matching capacitor C2 can be provided in the primary stage of the balun 23, thereby adjusting the capacitive reactance of both the primary and secondary stages of the balun. If impedance matching requirements can be met without adjusting the capacitive reactance of the primary stage of the balun, the first matching capacitor C1 and the second matching capacitor C2 can also be omitted, although this application does not limit this.

[0352] In some embodiments, as shown in Figures 61 and 62, the power amplifier 10 further includes a fourth matching capacitor C4 and a fifth matching capacitor C5. The fourth matching capacitor C4 is connected in series between the output or input of the power amplifier and the first end of the third coupling line; the fifth matching capacitor C5 is connected in series between the second end of the third coupling line and the third ground terminal. The input of the power amplifier is a port for receiving a radio frequency input signal RF_in, and the output is a port for outputting a radio frequency signal RF_out.

[0353] As an embodiment, when the balun 23 is used for output impedance matching of the power amplifier, the first end of the third coupling line cp3 is used to output the RF signal RF_out generated by coupling, so the first end of the third coupling line cp3 is connected to the output end of the power amplifier. At this time, as shown in Figure 61, the fourth matching capacitor C4 is connected in series between the first end of the third coupling line cp3 and the output end of the power amplifier, and the fifth matching capacitor C5 is connected in series between the second end of the third coupling line cp3 and the third ground end. The fourth matching capacitor C4 and the fifth matching capacitor C5 and the balun 23 jointly participate in the output impedance matching of the power amplifier.

[0354] As an embodiment, when the balun 23 is used for input impedance matching of the power amplifier, the first end of the third coupling line cp3 is used to receive the RF input signal RF_in from the previous stage circuit, so the first end of the third coupling line cp3 is connected to the input end of the power amplifier. At this time, as shown in Figure 62, the fourth matching capacitor C4 is connected in series between the first end of the third coupling line cp3 and the input end of the power amplifier, and the fifth matching capacitor C5 is connected in series between the second end of the third coupling line cp3 and the third ground end. The fourth matching capacitor C4 and the fifth matching capacitor C5 and the balun 23 jointly participate in the input impedance matching of the power amplifier.

[0355] Similar to Figures 59 and 60, the fourth matching capacitor C4 and the fifth matching capacitor C5 in this embodiment are also used to adjust the capacitive reactance of the balun secondary, thereby jointly participating in the impedance matching of the power amplifier with the balun, thereby improving the operating efficiency of the power amplifier. Compared with Figures 59 and 60, the embodiment of the present application splits the third matching capacitor C3, which was originally only provided at one end of the third coupling line cp3, into two matching capacitors C4 and C5, and provides the two matching capacitors C4 and C5 at both ends of the third coupling line cp3, which can enhance the balance of the circuit.

[0356] As an implementation method, in order to improve the coupling lines of the balun, the lengths of the coupling lines are made approximately the same. Since the primary stage has two coupling lines in series and the secondary stage has one coupling line, the impedance value of the primary stage is higher than that of the secondary stage. When the balun 23 is used for output impedance matching, the secondary stage as the output end will cause the output impedance to be lower than the input impedance, and the circuit imbalance problem is more prominent. However, replacing the third matching capacitor C3 with a fourth matching capacitor C4 and a fifth matching capacitor C5 symmetrically arranged at both ends of the third coupling line cp3 can significantly improve the circuit imbalance problem.

[0357] Optionally, to further improve circuit balance, the capacitance of the fourth matching capacitor C4 can be equal to the capacitance of the fifth matching capacitor C5. Assuming the required capacitance of the balun secondary is c, the capacitance of the fourth matching capacitor C4 and the fifth matching capacitor C5 can both be set to 2c. The equivalent capacitance of the two capacitors connected in series is the required capacitance c.

[0358] Similarly, when the fourth matching capacitor C4 and the fifth matching capacitor C5 are provided on the secondary stage of the balun 23, the first matching capacitor C1 and the second matching capacitor C2 can be provided on the primary stage of the balun 23, thereby adjusting the capacitive reactance of the primary and secondary stages of the balun simultaneously. When the capacitive reactance of the primary stage of the balun is not adjusted to meet the impedance matching requirements, the first matching capacitor C1 and the second matching capacitor C2 can also be omitted, and this application is not limited to this.

[0359] An embodiment of the present application also provides a chip, which includes the power amplifier described in any of the above embodiments.

[0360] In some embodiments, the power amplifier also includes a balun, the balun includes a primary coupling line and a secondary coupling line coupled to each other, the first segment of the primary coupling line and the first segment of the secondary coupling line are arranged between the first power amplifier circuit and the first edge of the chip; the second segment of the primary coupling line and the second segment of the secondary coupling line are arranged between the second power amplifier circuit and the second edge of the chip.

[0361] In some embodiments, the power amplifier further includes a balun and a bias module, and the bias module is disposed inside the balun.

[0362] For example, it can be applied to power amplification of WiFi signals, and the operating frequency band of the chip is 5.125 GHz to 7.125 GHz.

[0363] For other implementations of the chip, please refer to the description of the above embodiments and will not be repeated here.

[0364] In the chip of the present application embodiment, the first amplifier transistor in the first power amplifier circuit and the second amplifier transistor in the second power amplifier circuit are arranged in different directions, thereby reducing the chip length requirement, thereby shortening the chip length and reducing the chip area. Furthermore, integrating the balun within the chip can improve the chip's integration density, thereby reducing the size of the RF front-end module.

[0365] An embodiment of the present application further provides a radio frequency front-end module, which includes a substrate and a chip disposed on the substrate, wherein the chip integrates a power amplifier as described in any of the above embodiments.

[0366] An embodiment of the present application also provides a radio frequency front-end module. Figure 63 shows a schematic structural diagram of a radio frequency front-end module provided by an embodiment of the present application. As shown in Figure 63, the radio frequency front-end module 30 includes: a substrate 31 and a chip 32 arranged on the substrate 31, wherein the chip 32 has a first edge and a second edge intersecting each other; a first power amplifier circuit 321 and a second power amplifier circuit 323 are integrated in the chip 32, the first power amplifier circuit 321 includes a plurality of first amplifier transistors connected in parallel, and the plurality of first amplifier transistors are arranged along the first edge; the second power amplifier circuit 322 includes a plurality of second amplifier transistors connected in parallel, and the plurality of second amplifier transistors are arranged along the second edge.

[0367] In some embodiments, as shown in Figure 64, the RF front-end module 30 also includes a balun 33, wherein the balun 33 is arranged on the substrate and connected to the chip 32; specifically, the balun 33 includes a primary coupling line and a secondary coupling line coupled to each other, and the primary coupling line and the secondary coupling line both include a first segment and a second segment connected to each other, and the first segment extends in a direction parallel to the first edge, and the second segment extends in a direction parallel to the second edge.

[0368] In some embodiments, the substrate includes at least one metal layer, and the primary coupling line and the secondary coupling line may be located in the same metal layer of the substrate. When the substrate includes multiple metal layers, the primary coupling line and the secondary coupling line may also be located in different metal layers of the substrate.

[0369] When the primary and secondary coupling lines are located on different metal layers, the chip can be packaged on the substrate using a flip-chip package. Compared to wire bonding, flip-chip packaging has smaller parasitic parameters at the connection between the chip and the balun, which can offset the impact of the primary and secondary coupling lines on the balun's Q value to a certain extent.

[0370] For other implementations of the balun 33 , reference may be made to the introduction of the balun 23 in the above embodiments, which will not be repeated here.

[0371] In the RF front-end module of the present embodiment, the first amplifying transistor in the first power amplifier circuit and the second amplifying transistor in the second power amplifier circuit are arranged in different directions, thereby reducing the chip length requirement, thereby shortening the chip length and reducing the chip area. Placing the balun on a substrate outside the chip can appropriately extend the length of each coupling line in the balun, achieving greater inductance, making it suitable for use in lower frequency scenarios and having a wider range of applications.

[0372] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A power amplifier, characterized in that: It includes a first power amplifier circuit, a second power amplifier circuit and a balun, wherein the first power amplifier circuit and the second power amplifier circuit are respectively connected to the balun; The balun includes: a primary coupling line, the primary coupling line comprising a first input end and a second input end; A secondary coupling line, the secondary coupling line comprising a first output end and a second output end; The first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

2. The power amplifier according to claim 1, characterized in that: The primary coupling line includes a first primary coupling line and a second primary coupling line, and the secondary coupling line is arranged between the first primary coupling line and the second primary coupling line.

3. The power amplifier according to claim 2, characterized in that: The balun includes an odd number of bending segments, at which the first primary coupling line includes a first line segment and a second line segment connected at a first angle, the secondary coupling line includes a third line segment and a fourth line segment connected at the first angle, and the second primary coupling line includes a fifth line segment and a sixth line segment connected at the first angle, wherein at the odd number of the bending segments: The first line segment, the third line segment and the fifth line segment are arranged in parallel in sequence and their lengths increase in sequence; The second line segment, the fourth line segment and the sixth line segment are sequentially arranged in parallel and their lengths decrease sequentially.

4. The power amplifier according to claim 3, characterized in that: The difference between the lengths of the third line segment and the first line segment, the difference between the lengths of the fifth line segment and the third line segment, the difference between the lengths of the second line segment and the fourth line segment, and the difference between the lengths of the fourth line segment and the sixth line segment are all first values.

5. The power amplifier according to any one of claims 2 to 4, characterized in that: The length of the first primary coupling line, the length of the second primary coupling line and the length of the secondary coupling line are the same.

6. The power amplifier according to any one of claims 2 to 4, characterized in that: The first input end of the first primary coupling line and the first input end of the second primary coupling line are respectively connected to the output end of the first power amplifier circuit, and the second input end of the first primary coupling line and the second input end of the second primary coupling line are respectively connected to the output end of the second power amplifier circuit; The first output end of the secondary coupling line is used to connect to the signal transmission end, and the second output end of the secondary coupling line is used to be grounded.

7. The power amplifier according to any one of claims 2 to 4, characterized in that: The first input end of the first primary coupling line is used to connect to the output end of the first power amplifier circuit, and the second input end of the first primary coupling line is used to be grounded; The first input end of the second primary coupling line is used for grounding, and the second input end of the second primary coupling line is used for connecting to the output end of the second power amplifier circuit; The first output end of the secondary coupling line is used to connect to the signal transmission end, and the second output end of the secondary coupling line is used to be grounded.

8. The power amplifier according to any one of claims 2 to 4, characterized in that: The first input end of the first primary coupling line and the first input end of the second primary coupling line are respectively used to receive a radio frequency input signal, and the second input end of the first primary coupling coil and the second input end of the second primary coupling line are respectively used to be grounded; The first output end of the secondary coupling line is connected to the input end of the first power amplifier circuit, and the second output end of the secondary coupling line is connected to the input end of the second power amplifier circuit.

9. The power amplifier according to claim 1, characterized in that: The balun includes N primary coupling lines and M secondary coupling lines, and the N primary coupling lines and the M secondary coupling lines are arranged alternately on the same metal layer; wherein N and M are both positive integers, and N=M+1 or N=M-1.

10. The power amplifier according to claim 1, characterized in that: The secondary coupling line includes a first secondary coupling line and a second secondary coupling line, and the primary coupling line is arranged between the first secondary coupling line and the second secondary coupling line.

11. The power amplifier according to claim 10, characterized in that: The balun includes an odd number of bending segments, at which the first secondary coupling line includes a seventh segment and an eighth segment connected at a second angle, the primary coupling line includes a ninth segment and a tenth segment connected at a second angle, and the second secondary coupling line includes an eleventh segment and a twelfth segment connected at a second angle, wherein at the odd number of the bending segments: The seventh line segment, the ninth line segment and the eleventh line segment are parallel to each other and their lengths increase in sequence; The eighth line segment, the tenth line segment and the twelfth line segment are parallel to each other and their lengths decrease in sequence.

12. The power amplifier according to claim 11, characterized in that: The difference between the lengths of the ninth line segment and the seventh line segment is equal to the difference between the lengths of the eleventh line segment and the ninth line segment, and the difference between the lengths of the eighth line segment and the tenth line segment is equal to the difference between the lengths of the tenth line segment and the twelfth line segment.

13. The power amplifier according to any one of claims 10 to 12, characterized in that: The length of the first secondary coupling line, the length of the second secondary coupling line and the length of the primary coupling line are the same.

14. The power amplifier according to any one of claims 10 to 12, characterized in that: The first input end of the primary coupling line is connected to the output end of the first power amplifier circuit, and the second input end of the primary coupling line is connected to the output end of the second power amplifier circuit; The first output end of the first secondary coupling line and the first output end of the second secondary coupling line are respectively used to connect to the signal transmission end, and the second output end of the first secondary coupling line and the second output end of the second secondary coupling line are respectively used to be grounded.

15. The power amplifier according to any one of claims 10 to 12, characterized in that: The first input end of the primary coupling line is used to receive a radio frequency input signal, and the second input end of the primary coupling line is used to be grounded; The first output end of the first secondary coupling line and the first output end of the second secondary coupling line are respectively connected to the input end of the first power amplifier, and the second output end of the first secondary coupling line and the second output end of the second secondary coupling line are respectively connected to the input end of the second power amplifier.

16. The power amplifier according to any one of claims 10 to 12, characterized in that: The first input end of the primary coupling line is used to receive a radio frequency input signal, and the second input end of the primary coupling line is used to be grounded; The first output end of the first secondary coupling line is connected to the input end of the first power amplifier circuit, and the second output end of the first secondary coupling line is used for grounding; The first output end of the second secondary coupling line is used for grounding, and the second output end of the second secondary coupling line is connected to the input end of the second power amplifier circuit.

17. The power amplifier according to claim 1, characterized in that: The primary coupling line and the secondary coupling line are arranged in a straight line, a folded line, an L shape, a U shape or an arc shape.

18. A chip, characterized in that: The device comprises at least one power amplifier, wherein the power amplifier comprises a first power amplifier circuit, a second power amplifier circuit and a balun, wherein the first power amplifier circuit and the second power amplifier circuit are respectively connected to the balun; The balun includes: a primary coupling line, the primary coupling line comprising a first input end and a second input end; A secondary coupling line, the secondary coupling line comprising a first output end and a second output end; The first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

19. The chip according to claim 18, characterized in that: The primary coupling line and the secondary coupling line are arranged on the substrate in a straight line, a folded line, an L shape, a U shape or an arc shape.

20. The chip according to claim 19, characterized in that The first power amplifier circuit includes a plurality of first amplifier transistors connected in parallel, and the second power amplifier circuit includes a plurality of second amplifier transistors connected in parallel; The primary coupling line and the secondary coupling line are both arranged in a straight line, and a plurality of the first amplifying transistors and a plurality of the second amplifying transistors are arranged side by side on one side of the balun along the extension direction of the primary coupling line and the secondary coupling line.

21. The chip according to claim 20, characterized in that: The chip includes at least two power amplifiers, each of which is arranged side by side along a preset arrangement direction, and the baluns in each of the power amplifiers extend along the same direction, wherein the arrangement direction is perpendicular to the extension direction of any of the baluns.

22. The chip according to any one of claims 18 to 21, characterized in that: The chip includes at least one metal layer, and the primary coupling line and the secondary coupling line are located in the same metal layer; or, when the primary coupling line or the secondary coupling line includes multiple lines, at least one primary coupling line and at least one secondary coupling line are located in the same metal layer.

23. A radio frequency front-end module, characterized in that: Includes base plate, and: A power amplifier chip is arranged on the substrate; A balun is disposed on the substrate and connected to the power amplifier chip, and the balun includes: a primary coupling line, the primary coupling line comprising a first input end and a second input end; A secondary coupling line, the secondary coupling line comprising a first output end and a second output end; The first routing path of the primary coupling line follows the second routing path of the secondary coupling line, the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

24. The radio frequency front-end module according to claim 23, characterized in that: The power amplifier chip integrates a first power amplifier circuit and a second power amplifier circuit; The output end of the first power amplifier circuit and the output end of the second power amplifier circuit are respectively connected to the primary coupling line of the balun, and the secondary coupling line of the balun is connected to the signal transmission end.

25. The radio frequency front-end module according to claim 23, characterized in that: The power amplifier chip integrates a first power amplifier circuit and a second power amplifier circuit; The output end of the first power amplifier circuit and the output end of the second power amplifier circuit are respectively connected to the secondary coupling line of the balun, and the primary coupling line of the balun is used to receive a radio frequency input signal.

26. The radio frequency front-end module according to any one of claims 23 to 25, characterized in that: The primary coupling line and the secondary coupling line are arranged on the substrate in a straight line, a folded line, an L shape, a U shape or an arc shape.

27. The radio frequency front-end module according to any one of claims 23 to 25, characterized in that: The substrate includes at least one metal layer, and the primary coupling line and the secondary coupling line are located in the same metal layer; or, when the primary coupling line or the secondary coupling line includes multiple lines, at least one primary coupling line and at least one secondary coupling line are located in the same metal layer.

28. A transformer structure, characterized in that: include: a primary coupling line, the primary coupling line comprising a first input end and a second input end; A secondary coupling line, the secondary coupling line comprising a first output end and a second output end; The first routing path of the primary coupling line follows the second routing path of the secondary coupling line, and the first routing path is a routing path from the first input end to the second input end, and the second routing path is a routing path from the first output end to the second output end.

29. The transformer structure according to claim 28, characterized in that: The primary coupling line and the secondary coupling line are both arranged in a straight line or a folded line.

30. The transformer structure according to claim 28, characterized in that: The primary coupling line and the secondary coupling line are both arranged in an L shape.

31. The transformer structure according to claim 28, characterized in that: The primary coupling line and the secondary coupling line are both arranged in a U shape.

32. The transformer structure according to any one of claims 25 to 28, characterized in that: The length of the primary coupling line is equal to the length of the secondary coupling line.

33. The transformer structure according to claim 25, characterized in that: The primary coupling line and the secondary coupling line are both arranged in an arc shape.

34. The transformer structure according to claim 33, characterized in that: The arc center angles of the primary coupling line and the secondary coupling line are both less than or equal to 270°.

35. The transformer structure according to claim 33, characterized in that: The arc center angles of the primary coupling line and the secondary coupling line are both less than or equal to 180°.

36. The transformer structure according to any one of claims 28 to 35, characterized in that: The primary coupling line and the secondary coupling line are located in the same plane; or, when the primary coupling line or the secondary coupling line comprises a plurality of lines, at least one of the primary coupling lines and at least one of the secondary coupling lines are located in the same plane.

37. A power amplifier, characterized in that: The invention comprises a first power amplifier circuit, a second power amplifier circuit and a balun, wherein the balun comprises: A first coupling line, wherein a first end of the first coupling line is connected to an output end or an input end of the first power amplifier circuit, and a second end of the first coupling line is connected to a first ground end; A second coupling line, wherein a first end of the second coupling line is connected to an output end or an input end of the second power amplifier circuit, and a second end of the second coupling line is connected to a second ground end; A third coupling line, wherein a first end of the third coupling line is connected to the output end or the input end of the power amplifier, and a second end of the third coupling line is connected to a third ground end.

38. The power amplifier according to claim 37, characterized in that The third coupling line is disposed between the first coupling line and the second coupling line, and is mutually coupled with the first coupling line and the second coupling line.

39. The power amplifier according to claim 37, characterized in that The power amplifier further comprises a first matching capacitor and a second matching capacitor, wherein: The first matching capacitor is connected in series between the output end or the input end of the first power amplifier circuit and the first end of the first coupling line, and the second matching capacitor is connected in series between the output end or the input end of the second power amplifier circuit and the first end of the second coupling line; Alternatively, the first matching capacitor is connected in series between the second end of the first coupling line and the first ground terminal, and the second matching capacitor is connected in series between the second end of the second coupling line and the second ground terminal.

40. The power amplifier according to claim 37, characterized in that The power amplifier also includes a third matching capacitor, wherein the third matching capacitor is connected in series between the output end or the input end of the power amplifier and the first end of the third coupling line; or, the third matching capacitor is connected in series between the second end of the third coupling line and the third ground end; or, the third matching capacitor is connected in series between the first end and the second end of the third coupling line.

41. The power amplifier according to claim 37, characterized in that The power amplifier further includes a fourth matching capacitor and a fifth matching capacitor, wherein: The fourth matching capacitor is connected in series between the output end or the input end of the power amplifier and the first end of the third coupling line; The fifth matching capacitor is connected in series between the second end of the third coupling line and the third ground end.

42. The power amplifier according to claim 41, characterized in that The fourth matching capacitor and the fifth matching capacitor have the same capacitance.

43. The power amplifier according to any one of claims 37 to 42, characterized in that: The first ground terminal and the second ground terminal are grounded through different paths.

44. A power amplifier, characterized in that: include: A first power amplifier circuit, the first power amplifier circuit comprising a plurality of first amplifier transistors connected in parallel, the plurality of first amplifier transistors being arranged along a first direction; A second power amplifier circuit, the second power amplifier circuit comprising a plurality of second amplifier transistors connected in parallel, the plurality of second amplifier transistors being arranged along a second direction; The first direction intersects with the second direction.

45. The power amplifier according to claim 44, characterized in that A plurality of the first amplifying transistors are arranged in a first layout area, and a plurality of the second amplifying transistors are arranged in a second layout area; the power amplifier also includes a balun, which is arranged outside the first layout area and the second layout area; or, the balun is arranged inside the first layout area and the second layout area.

46. ​​The power amplifier according to claim 45, characterized in that The output end of the first power amplifier circuit and the output end of the second power amplifier circuit are respectively connected to the balun; or, the input end of the first power amplifier circuit and the input end of the second power amplifier circuit are respectively connected to the balun; Among them, the connection point between the balun and the first power amplifier circuit is set close to the midpoint of one side of the first layout area; the connection point between the balun and the second power amplifier circuit is set close to the midpoint of one side of the second layout area.

47. The power amplifier according to claim 44, characterized in that The power amplifier also includes a balun, which includes a primary coupling line and a secondary coupling line coupled to each other, wherein the primary coupling line and the secondary coupling line each include a first segment and a second segment connected to each other, and the first segment extends along the first direction and the second segment extends along the second direction.

48. The power amplifier according to claim 44 or 45, characterized in that The first direction is perpendicular to the second direction.

49. The power amplifier according to claim 44, characterized in that The power amplifier further comprises a third power amplifier circuit, the output end of the third power amplifier circuit is connected to the input end of the first power amplifier circuit and the input end of the second power amplifier circuit; Wherein, the third power amplifier circuit includes a plurality of third amplifier transistors, and the plurality of third amplifier transistors are arranged along the first direction or the second direction; or, some of the third amplifier transistors are arranged along the first direction, and another part of the third amplifier transistors are arranged along the second direction.

50. The power amplifier according to claim 49, characterized in that The power amplifier also includes an inter-stage matching circuit, the input end of the inter-stage matching circuit is connected to the output end of the third power amplifier circuit, and the output end of the inter-stage matching circuit is connected to the input end of the first power amplifier circuit and the input end of the second power amplifier circuit.

51. The power amplifier according to claim 50, characterized in that The inter-stage matching circuit is arranged in an inter-stage layout area, and the inter-stage layout area includes a first side away from the first power amplifier circuit and a second side away from the second power amplifier circuit, wherein some of the third amplifier transistors are arranged along a direction parallel to the first side, and another part of the third amplifier transistors are arranged along a direction parallel to the second side.

52. The power amplifier according to claim 51, characterized in that The inter-stage matching circuit includes a transformer, and the transformer includes an input coupling line and an output coupling line coupled to each other; Wherein, the input coupling line and the output coupling line each include a third segment and a fourth segment connected to each other, and the third segment extends along the first direction, and the fourth segment extends along the second direction; Alternatively, the input coupling line and the output coupling line are both arranged along the edge of the inter-stage layout area.

53. The power amplifier according to claim 45, characterized in that The first power amplifier circuit and the second power amplifier circuit are integrated in a chip, and the chip includes a first edge and a second edge intersecting each other, the first direction is parallel to the first edge, and the second direction is parallel to the second edge.

54. The power amplifier according to claim 53, characterized in that The power amplifier further includes a bias module, which is disposed in the fourth layout area and is respectively connected to the first power amplifier circuit and the second power amplifier circuit; The fourth layout area is located between one end of the first layout area and the second edge, and between one end of the second layout area and the first edge.

55. The power amplifier according to claim 44, characterized in that The operating frequency band of the power amplifier is 5.125 GHz to 7.125 GHz.

56. The chip according to claim 53, characterized in that The power amplifier further comprises a balun, wherein the balun comprises a primary coupling line and a secondary coupling line coupled to each other. The first section of the primary coupling line and the first section of the secondary coupling line are arranged between the first power amplifier circuit and the first edge of the chip; The second section of the primary coupling line and the second section of the secondary coupling line are arranged between the second power amplifier circuit and a second edge of the chip.

57. A radio frequency front-end module, characterized in that: include: substrate; A chip is disposed on the substrate, wherein the chip has a first edge and a second edge intersecting each other; The chip includes: A first power amplifier circuit, the first power amplifier circuit comprising a plurality of first amplifier transistors connected in parallel, the plurality of first amplifier transistors being arranged along the first edge; The second power amplifier circuit includes a plurality of second amplifier transistors connected in parallel, and the plurality of second amplifier transistors are arranged along the second edge.

58. The radio frequency front-end module according to claim 57, characterized in that: Also includes: A balun, disposed on the substrate and connected to the chip; The balun includes a primary coupling line and a secondary coupling line coupled to each other, wherein the primary coupling line and the secondary coupling line each include a first segment and a second segment connected to each other, and the first segment extends in a direction parallel to the first edge, and the second segment extends in a direction parallel to the second edge.

59. The radio frequency front-end module according to claim 57, characterized in that: The substrate comprises multiple metal layers, the primary coupling line and the secondary coupling line are located in different metal layers of the substrate, and the chip is flip-flopped and packaged on the substrate.

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