A feedback circuit, a multi-port low noise amplifier and a radio frequency front-end module

Abstract

The application relates to the technical field of amplifiers, and discloses a feedback circuit, a multi-port low-noise amplifier and a radio frequency front-end module. The feedback circuit comprises a first extension part, a second extension part, a first connecting part and an inductor main body. At least two connecting ends are arranged on the first extension part at intervals, different connecting ends are connected with different first amplification units corresponding to different radio frequency input ports in the multi-port low-noise amplifier respectively, one end of the first extension part and a first end of the second extension part are connected with the first connecting part respectively, and the first extension part and the second extension part are oppositely arranged. When current is connected, the current direction of the first extension part is opposite to the current direction of the second extension part. The application can solve the problem of unbalanced inductance value provided by the feedback circuit and reduce the difference between the amplification gains of different radio frequency input ports.

Description

Technical Field

[0001] This invention relates to the field of amplifier technology, and more particularly to a feedback circuit, a multi-port low-noise amplifier, and a radio frequency front-end module. Background Technology

[0002] In current multi-port low noise amplifier (LNA) designs, in order to support applications across multiple frequency bands and meet increasingly complex carrier aggregation (CA) requirements, as well as various complex usage scenarios, some radio frequency (RF) input ports of the low noise amplifier have been multiplexed.

[0003] The port multiplexing circuit of the multi-port low-noise amplifier in the relevant scheme has an independent transconductance (GM) amplification unit for each RF input port. A secondary switch selects any one of the GM amplification units to connect to the cascode amplification unit, thereby achieving frequency band switching. Each frequency band's RF input port has an independent GM amplification unit; switching is used to select the 1st to Nth RF input ports and their corresponding GM amplification units to connect to the cascode amplification unit, thus achieving multiplexing of multiple frequency bands.

[0004] This solution avoids insertion loss caused by input port switching and has good noise figure performance. However, in the inductor layout design of the feedback circuit, the distribution positions of the transconductance amplifier units corresponding to different RF input ports are different, and the distance from the inductor connection terminal to the inductor end of different transconductance amplifier units is different. This results in different inductance values ​​connected to different transconductance amplifier units, that is, different inductance values ​​connected to different transconductance amplifier units by the feedback circuit. Therefore, the multi-port low-noise amplifier has an imbalance problem in the inductance value provided by the feedback circuit, which leads to inconsistent amplification gain of different RF input ports. Summary of the Invention

[0005] In view of this, the present invention provides a feedback circuit, a multi-port low-noise amplifier, and an RF front-end module to solve or partially solve the technical problem of unbalanced inductance values ​​provided by the feedback circuit in related solutions.

[0006] The technical solution proposed in this invention is as follows:

[0007] In a first aspect, the present invention provides a feedback circuit applied to a multi-port low-noise amplifier, comprising: an inductor, the inductor including a first extension, a second extension, a first connecting portion, and an inductor body; at least two connecting ends are spaced apart on the first extension, and different connecting ends are respectively connected to first amplification units corresponding to different radio frequency input ports in the multi-port low-noise amplifier; the two ends of the first connecting portion are respectively connected to one end of the first extension and the first end of the second extension, the first extension and the second extension are arranged opposite to each other, when current is applied, the current direction of the first extension and the current direction of the second extension are opposite, and the magnetic field lines generated by the first extension and the magnetic field lines generated by the second extension partially cancel each other out, so that the inductance value of the connection portion from the at least two connecting ends on the first extension to the second end of the inductor body is equal; the first end of the inductor body and the second extension are connected, and the second end of the inductor body is connected to a ground terminal.

[0008] The feedback circuit of the present invention connects one end of the first extension and the first end of the second extension through the first connecting portion, so that the first extension and the second extension are opposite. When current is applied, the current direction of the first extension and the current direction of the second extension are opposite. According to the right-hand rule, the magnetic field lines generated by the first extension and the magnetic field lines generated by the second extension will partially cancel each other out. Since the longer the connection from the connecting end to the second end of the inductor body, the more magnetic field lines are canceled out, the inductance value of the connection from at least two connecting ends on the first extension to the second end of the inductor body can be made equal. This makes the inductance value connected to the first amplification unit corresponding to different RF input ports in the multi-port low noise amplifier equal, solving the problem of unbalanced inductance value provided by the feedback circuit and reducing the difference in amplification gain between different RF input ports.

[0009] Optionally, the projection of any connecting end on the first extension along the first direction is located on the second extension, and the first direction is perpendicular to the extension direction of the second extension.

[0010] In this method, since the projection of the connecting end on the first extension along the first direction is located on the second extension, the interaction effect between the first extension and the second extension when generating a magnetic field can be enhanced.

[0011] Optionally, the inductor further includes a third extension and a second connection portion; the third extension is provided with at least two connection terminals spaced apart, and the different connection terminals are respectively connected to the first amplification unit corresponding to different RF input ports in the multi-port low noise amplifier; the two ends of the second connection portion are respectively connected to the second end of the second extension and one end of the third extension portion, the second extension portion and the third extension portion are arranged opposite to each other, when current is applied, the current direction of the second extension portion is opposite to the current direction of the third extension portion, and the magnetic field lines generated by the second extension portion and the magnetic field lines generated by the third extension portion partially cancel each other out, so that the inductance value of the connection portion from the at least two connection terminals on the third extension portion to the second end of the inductor body is equal.

[0012] In this approach, the number of connection terminals is expanded by symmetrical arrangement, which can better meet the port number requirements of multi-port low-noise amplifiers.

[0013] Optionally, the inductor body includes a first connecting portion and a coil portion, a first end of the first connecting portion and a second extension portion are connected, a second end of the first connecting portion and a first end of the coil portion are connected, and a second end of the coil portion and a ground terminal are connected.

[0014] In this method, the coil section can be arranged in a suitable position in the layout of the multi-port low-noise amplifier through the first connection part, and the coil section can be moved away from the first extension, the second extension and the third extension, thereby reducing the influence of the coil section on the magnetic field of the first extension, the second extension and the third extension.

[0015] Optionally, when the distance between the coil portion and the second extension portion is greater than the first threshold and the first connecting portion is perpendicular to the second extension portion, the connection position of the first connecting portion and the second extension portion is located at the center of the second extension portion.

[0016] In this method, the coil portion has a small influence on the magnetic field of the first extension portion and the third extension portion, and the influence on both sides is basically the same. Therefore, when the connection position of the first connection portion and the third extension portion is located at the center position of the second extension portion, it can be ensured that the inductance value of the line portion connecting the connection end on the first extension portion to the second end of the inductor body is equal to the inductance value of the line portion connecting the connection end on the third extension portion to the second end of the inductor body.

[0017] Optionally, when the distance between the coil portion and the second extension portion is less than the second threshold, the connection position of the first connecting portion and the second extension portion is biased towards the first extension portion or towards the third extension portion.

[0018] In this method, the small distance between the coil portion and the second extension portion will cancel or enhance the magnetic field of the first extension portion and / or the third extension portion. By biasing the connection position of the first connection portion and the second extension portion toward the first extension portion or toward the third extension portion, the magnetic field coupling effect of the coil portion can be reduced by the different connection distances on both sides, so that the inductance value of the connection portion from the connection end on the first extension portion to the second end of the inductor body is equal to the inductance value of the connection portion from the connection end on the third extension portion to the second end of the inductor body.

[0019] Optionally, the first connecting portion and the second extension portion are perpendicular, and the offset direction of the connection position of the first connecting portion and the second extension portion is opposite to the current direction of the trace closest to the second extension portion in the coil portion.

[0020] In this method, when the first connection part and the second extension part are perpendicular, the trace closest to the second extension part in the coil part has the effect of weakening the inductance value of the magnetic field coupling to the second extension part opposite to it. Therefore, it is necessary to shift the connection position of the first connection part and the second extension part in the opposite direction to the current direction of the trace closest to the second extension part in the coil part in order to counteract the weakening effect of the magnetic field coupling.

[0021] Optionally, the first connecting portion deflects toward the first extension portion or the third extension portion, the current direction of the coil portion closest to the second extension portion is opposite to the current direction of the deflected extension portion, and the connection position of the first connecting portion and the second extension portion is shifted away from the deflected extension portion.

[0022] In this method, the first connection portion can be deflected toward the first extension portion or the third extension portion according to the inductor layout requirements. If the current direction of the trace closest to the second extension portion of the coil portion is opposite to the current direction of the deflected extension portion, the coupling effect of the coil portion will weaken the inductance value connected to the connection terminal on the deflected extension portion. Therefore, the connection position of the first connection portion and the second extension portion is shifted away from the deflected extension portion to increase the inductance value connected to the connection terminal on the deflected extension portion, ensuring that the inductance values ​​connected to the connection terminals on the two extension portions are equal.

[0023] Optionally, the first connecting portion deflects toward the first extension portion or the third extension portion, the current direction of the trace closest to the second extension portion of the coil portion is the same as the current direction of the deflected extension portion, and the connection position of the first connecting portion and the second extension portion is shifted toward the direction of the deflected extension portion.

[0024] In this method, the coupling effect of the coil section enhances the inductance value connected to the connection terminal on the deflection extension. Therefore, the connection position of the first connection section and the second extension section is shifted towards the direction of the deflection extension section, reducing the inductance value connected to the connection terminal on the deflection extension section, and ensuring that the inductance values ​​connected to the connection terminals on the two extension sections are equal.

[0025] Optionally, the distance between the first extension and the second extension is between 15 μm and 25 μm.

[0026] In this method, when the distance between the first extension and the second extension is between 15μm and 25μm, the inductance values ​​connected to the connection terminals at different positions on the first extension can be equal.

[0027] Optionally, the second end of the coil is connected to the ground terminal via the first switch, and the third end of the coil is connected to the ground terminal via the second switch, with the third end of the coil located between the first end and the second end of the coil.

[0028] In this method, the first switch can be controlled to close or open according to the amplification gain requirements, thereby changing the inductance value and improving the flexibility of the feedback circuit.

[0029] Optionally, the coil section includes a first coil and a second coil, a first end of the first coil is connected to a second end of the first connecting part, the second end of the first coil is connected to the first end of the second coil through the second connecting part, the second connecting part is connected to a ground terminal through a third switch, and the second end of the second coil is connected to a ground terminal through a fourth switch.

[0030] In this method, the third and fourth switches can be closed or opened according to the amplification gain requirements, thereby changing the inductance value and improving the flexibility of the feedback circuit. Furthermore, by using two coils, the inductance value can be varied more significantly.

[0031] In a second aspect, the present invention provides a multi-port low-noise amplifier, including at least two radio frequency input ports and a feedback circuit as described in any of the first aspects of the present invention, wherein each radio frequency input port is connected to a first amplification unit, and the sources of at least two first amplification units are respectively connected to at least two connection terminals in the feedback circuit.

[0032] Thirdly, the present invention provides a radio frequency front-end module, including a multi-port low-noise amplifier as described in the second aspect of the present invention. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a circuit schematic of a multi-port low-noise amplifier in related technologies;

[0035] Figure 2 This is a circuit schematic of another multi-port low-noise amplifier in the related technology;

[0036] Figure 3 This is a schematic diagram of the feedback circuit of a multi-port low-noise amplifier in related technologies;

[0037] Figure 4 This is a schematic diagram of the structure of a feedback circuit in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the electromagnetic cancellation principle of a feedback circuit in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the electromagnetic cancellation principle of another feedback circuit in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of another feedback circuit in an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention;

[0042] Figure 9 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention;

[0043] Figure 10 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention;

[0044] Figure 11 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention;

[0045] Figure 12 This is a simulation result diagram of the inductance when the distance between the first extension and the second extension is different in an embodiment of the present invention;

[0046] Figure 13 This is a schematic diagram of the inductor structure of a feedback circuit in an embodiment of the present invention;

[0047] Figure 14 for Figure 13 Simulation results of the inductor in the feedback circuit;

[0048] Figure 15 This is a schematic diagram of the inductor structure of another feedback circuit in an embodiment of the present invention;

[0049] Figure 16 for Figure 14 Simulation results of the inductor in the feedback circuit;

[0050] Figure 17 This is a schematic diagram of the inductor structure of another feedback circuit in an embodiment of the present invention;

[0051] Figure 18 for Figure 14 Simulation results of the inductor in the feedback circuit;

[0052] Figure 19 This is a circuit schematic diagram of a multi-port low-noise amplifier in an embodiment of the present invention;

[0053] Explanation of reference numerals in the attached figures:

[0054] 1. First extension; 2. First connecting part; 3. Second extension; 4. Third extension; 5. Inductor body; 51. First connecting part; 52. Coil part; 521. First coil; 522. Second coil; 523. Second connecting part; s1. First switch; s2. Second switch; s3. Third switch; s4. Fourth switch; Ls1. First connecting end; Ls2. Second connecting end. Detailed Implementation

[0055] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0059] The two traditional types of multi-port low-noise amplifiers are as follows: Figure 1 and Figure 2 As shown. Figure 1 As shown, the first type of input uses a single-pole multi-throw (SPNT) switch to switch the input band; as... Figure 2As shown, the second method involves each RF input port having an independent transconductance (GM) amplification unit. A secondary switch selects any one of these transconductance amplification units to connect to a cascode amplification unit, thus enabling frequency band switching. Each frequency band's RF input port has an independent transconductance amplification unit. Switching allows selection of the 1st to Nth RF input ports and their corresponding transconductance amplification units to connect to the cascode amplification unit, thereby achieving multiplexing of multiple frequency bands.

[0060] The first type of multi-port low-noise amplifier is characterized by its simple circuitry and small size. However, it has the disadvantage of introducing switching insertion loss at the input, which leads to a deterioration of the noise figure (NF). Furthermore, due to the presence of the capacitance of the switch off state (Coff), the parasitic capacitance from the input of the low-noise amplifier to ground increases, making input matching more difficult and worsening the input return loss.

[0061] The second type of multi-port low-noise amplifier avoids insertion loss caused by switching the RF input port, resulting in good noise figure performance. However, in the inductor layout design of the feedback circuit, this approach suffers from different inductance values ​​due to the varying distribution positions of the transconductance amplifier units corresponding to different RF input ports and the different distances from the inductor connection terminals to the inductor ends of different transconductance amplifier units. For example, Figure 3 The distance from the inductor terminal to the inductor end of the transconductance amplifier unit connected to the RF input port RF1 is greater than the distance from the inductor terminal to the inductor end of the RF input port RF2. This results in different inductor values ​​connected to the transconductance amplifier units connected to different RF input ports in the feedback circuit. Therefore, the multi-port low-noise amplifier has an imbalance problem in the inductor value provided by the feedback circuit, which leads to inconsistent amplification gain of different RF input ports.

[0062] To address the issue of inconsistent amplification gains at different RF input ports in the second type of multi-port low-noise amplifier, this invention provides a feedback circuit that utilizes the electromagnetic cancellation principle to reduce the inductance differences of the transconductance amplification units connected to the RF input ports, thereby making the amplification gains of each RF input port tend to be consistent.

[0063] like Figure 4 As shown, the feedback circuit of this embodiment of the invention is applied to a multi-port low-noise amplifier and includes:

[0064] The inductor includes a first extension 1, a second extension 3, a first connecting part 2, and an inductor body 5; the first extension 1 is provided with at least two connection ends at intervals, and the different connection ends are respectively connected to the first amplification unit corresponding to different radio frequency input ports in the multi-port low noise amplifier.

[0065] The two ends of the first connecting part 2 are respectively connected to one end of the first extension part 1 and the first end of the second extension part 3. The first extension part 1 and the second extension part 3 are arranged opposite to each other. When current is applied, the current direction of the first extension part 1 and the current direction of the second extension part 3 are opposite. The magnetic field lines generated by the first extension part 1 and the magnetic field lines generated by the second extension part 3 partially cancel each other out, so that the inductance value of the connection part from at least two connecting ends on the first extension part 1 to the second end of the inductor body 5 is equal.

[0066] The first end of the inductor body 5 and the second extension 3 are connected, and the second end of the inductor body 5 is connected to the ground terminal. The second end of the inductor body 5 is the end of the inductor body 5.

[0067] Specifically, both the first extension 1 and the second extension 3 can adopt a straight line, a broken line, or a wavy line structure. The first extension 1 can have 2, 3, or 4 connecting ends, etc. The number of connecting ends can be set according to actual needs, and the connecting ends can be set at equal intervals or at unequal intervals.

[0068] In this embodiment of the invention, "equal inductance values" can be understood as the difference between two inductance values ​​being greater than a set minimum value. The set minimum value can be set according to actual accuracy requirements. For example, when the difference between two inductance values ​​is less than 0.5pH, the two inductance values ​​are considered equal.

[0069] Figure 4 This is a schematic diagram of the structure of the inductor in an embodiment of the present invention. The number of connection terminals on the first extension 1 is 2, namely the first connection terminal Ls1 and the second connection terminal Ls2. The first connection terminal Ls1 and the second connection terminal Ls2 are respectively connected to the source of the field-effect transistor in the first amplification unit corresponding to different radio frequency input ports in the multi-port low noise amplifier.

[0070] Based on the actual circuit layout space, such as Figure 4 As shown, the connection point between the inductor body 5 and the second extension 3 can be located on the side of the second extension 3 facing the first extension 1; or, as... Figure 7 As shown, the connection position of the inductor body 5 and the second extension 3 can be located on the side of the second extension 3 away from the first extension 1.

[0071] The length of the line connecting the first connection terminal Ls1 to the second end of the inductor body 5 is less than the length of the line connecting the second connection terminal Ls2 to the second end of the inductor body 5. In inductor design, the longer the transmission line, the greater the inductance value. Therefore, without considering the cancellation of magnetic field lines, the inductance value from the first connection terminal Ls1 to the second end of the inductor body 5 is less than the inductance value from the second connection terminal Ls2 to the second end of the inductor body 5.

[0072] In this embodiment of the invention, the first extension 1 and the second extension 3 are connected by the first connecting part 2 so that the first extension 1 and the second extension 3 are arranged vertically opposite to each other. When current is applied, the current direction of the first extension 1 and the current direction of the second extension 3 are opposite. According to the right-hand rule, the magnetic field lines generated by the first extension 1 and the magnetic field lines generated by the second extension 3 will partially cancel each other out. The longer the connection from the connecting end to the second end of the inductor body 5, the more magnetic field lines are canceled out. That is, when the second connecting end Ls2 is connected to the first amplification unit to apply current, the magnetic field lines generated by the first extension 1 and the magnetic field lines generated on the second extension 3 cancel out more than the part canceled out when the first connecting end Ls1 is connected to the first amplification unit.

[0073] Combination Figure 5 and Figure 6 As shown, the closer the distance S1 between the first extension 1 and the second extension 3, the more magnetic field lines cancel each other out, and the greater the degree of cancellation. After the width W1 of the first extension 1 and the width W2 of the second extension 3 are determined, the degree of magnetic field line cancellation can be adjusted by adjusting the distance S1 between the first extension 1 and the second extension 3. This, in turn, adjusts the inductance value of the connection between the first connecting end Ls1 and the inductor body 5 and the inductance value of the connection between the second connecting end Ls2 and the inductor body 5, so that the first connecting end... The inductance value of the connection between Ls1 and the inductor body 5 is equal to the inductance value of the connection between the second connection Ls2 and the inductor body 5. Since the first connection Ls1 and the second connection Ls2 share the same inductor body 5, the inductance value of the connection between the first connection Ls1 and the second end of the inductor body 5 is also equal to the inductance value of the connection between the second connection Ls2 and the second end of the inductor body 5. That is, the inductance value connected to the first connection Ls1 is equal to the inductance value connected to the second connection Ls2.

[0074] Furthermore, the distance between the first extension 1 and the second extension 3 is between 15 μm and 25 μm. When the distance between the first extension 1 and the second extension 3 is between 15 μm and 25 μm, the inductance value connected to the connection terminals at different positions on the first extension 1 can be equal. Wherein, the widths of the first extension 1 and the second extension 3 are different, and the corresponding distance between the first extension 1 and the second extension 3 will also vary. For example, if the widths of the first extension 1 and the second extension 3 are both 10 μm, when the distance between the first extension 1 and the second extension 3 is 20 μm, the inductance value connected to the connection terminals at different positions on the first extension 1 is equal; or, if the widths of the first extension 1 and the second extension 3 are both 12 μm, then the distance between the first extension 1 and the second extension 3 can be appropriately increased to 24 μm or 25 μm to ensure that the inductance value connected to the connection terminals at different positions on the first extension 1 is equal.

[0075] In one embodiment, the inductance value of the feedback circuit is verified using simulation software. For example... Figure 12 As shown, the widths of the first extension 1, the first connecting portion 2, and the third connecting portion are all 10 μm. When the distance S1 between the first extension 1 and the second extension 3 is 30 μm, the inductance value of the connection portion from the first connecting terminal Ls1 to the inductor body 5 is equal to 178.1 pH, and the inductance value of the connection portion from the second connecting terminal Ls2 to the inductor body 5 is equal to 188.5 pH. When the distance S1 between the first extension 1 and the second extension 3 is 20 μm, the inductance value of the connection portion from the first connecting terminal Ls1 to the inductor body... The inductance value of the connection portion of 5 is equal to 169.0 pH, and the inductance value of the connection portion from the second connection terminal Ls2 to the inductor body 5 is equal to 170.3 pH. These can be considered as the inductance values ​​of the two connection terminals being equal. When the distance S1 between the first extension portion 1 and the second extension portion 3 is 10 μm, the inductance value of the connection portion from the first connection terminal Ls1 to the inductor body 5 is equal to 152.3 pH, and the inductance value of the connection portion from the second connection terminal Ls2 to the inductor body 5 is equal to 170.3 pH.

[0076] The feedback circuit of this invention utilizes the magnetic field line cancellation principle to make the inductance values ​​of the connection portions from at least two connection terminals on the first extension 1 to the second end of the inductor body 5 equal. This ensures that the inductance values ​​connected to the first amplification units corresponding to different RF input ports in a multi-port low-noise amplifier are equal, thus solving the problem of unbalanced inductance values ​​provided by the feedback circuit and reducing the difference in amplification gain between different RF input ports.

[0077] In some embodiments, the projection of any connecting end on the first extension 1 along the first direction is located on the second extension 3, and the first direction is perpendicular to the extension direction of the second extension 3.

[0078] The projections of the connection ends on the first extension portion 1 along the first direction are all located on the second extension portion 3, which can make the current flowing positions on the second extension portion 3 cover the connection ends at various different positions, thereby enhancing the interaction effect between the first extension portion 1 and the second extension portion 3 when generating a magnetic field, enhancing the degree of cancellation of magnetic field lines, and when the connection end farther away from the first connection portion 2 accesses current, the enhancement effect is greater, and thus it is more convenient to achieve the same inductance.

[0079] In some embodiments, the inductor further includes a third extension portion 4 and a second connection portion; at least two connection ends are provided at intervals on the third extension portion 4; both ends of the second connection portion are respectively connected to the second end of the second extension portion 3 and one end of the third extension portion 4, the second extension portion 3 and the third extension portion 4 are parallel, when current is accessed, the current directions of the second extension portion 3 and the third extension portion 4 are opposite, and the magnetic induction lines generated by the second extension portion 3 and the magnetic induction lines generated by the third extension portion 4 partially cancel each other, so that the inductance values of the connection lines of at least two connection ends on the third extension portion 4 to the second end of the inductor body 5 are equal.

[0080] Specifically, the structures of the first connection portion 2 and the second connection portion are the same, and both adopt a "U" - shaped structure or a "匚" - shaped structure. Through the "U" - shaped structure or the "匚" - shaped structure, the first extension portion 1 and the third extension portion 4 can be respectively parallel to the second extension portion 3, and both the first extension portion 1 and the third extension portion 4 overlap with the second extension portion 3 in the first direction, which is beneficial to realizing that when there is current, the current direction of the first extension portion 1 is opposite to the current direction of the second extension portion 3, and the current direction of the third extension portion 4 is opposite to the current direction of the second extension portion 3.

[0081] It should be understood that due to the limitation of layout design, the arc part in the "U" - shaped structure is obtained by chamfering treatment, that is, the arc part in the "U" - shaped structure is actually composed of one or more mutually connected broken lines.

[0082] In one example, the second extension portion 3 is a smooth line segment, the first extension portion 1 and the third extension portion 4 are symmetrically arranged with respect to the central perpendicular line of the second extension portion 3, and there is a certain interval between the first extension portion 1 and the third extension portion 4 to facilitate the connection of the second extension portion 3 to the inductor body 5.

[0083] In another example, as Figure 6 shown, a stepped structure is provided in the part of the second extension portion 3 between the first extension portion 1 and the third extension portion 4, which can make the inductor be flexibly arranged at different positions on the layout.

[0084] In this embodiment, by adding the third extension portion, the number of connection ends can be expanded, and it can better meet the port number requirements of a multi - port low - noise amplifier.

[0085] In some embodiments, the inductor body 5 includes a first connecting portion 51 and a coil portion 52. The first end of the first connecting portion 51 and the second extension portion 3 are connected, the second end of the first connecting portion 51 and the first end of the coil portion 52 are connected, and the second end of the coil portion 52 is connected to a ground terminal.

[0086] Specifically, the first connecting part 51 can be a straight line segment structure or a broken line structure.

[0087] The coil section 52 consists of several coils, each coil being formed by connecting several broken line segments in sequence.

[0088] Depending on the actual circuit layout space, the connection position of the first connection part 51 and the second extension part 3 can be located on the side of the second extension part 3 away from the first extension part 1; or, the connection position of the first connection part 51 and the second extension part 3 can be located on the side of the second extension part 3 facing the first extension part 1.

[0089] The first connection portion 51 allows the coil portion 52 to be arranged in a suitable position in the layout of the multi-port low-noise amplifier, and also allows the coil portion 52 to be moved away from the first extension portion 1, the second extension portion 3 and the third extension portion 4, thereby reducing the influence of the coil portion 52 on the magnetic field of the first extension portion 1, the second extension portion 3 and the third extension portion 4.

[0090] In some embodiments, the second end of the coil portion 52 is connected to the ground terminal via the first switch s1, and the third end of the coil portion 52 is connected to the ground terminal via the second switch s2. The third end of the coil portion 52 is located between the first end and the second end of the coil portion 52.

[0091] Specifically, the third end of the coil section 52 is located at the midpoint of the overall trace distance of the coil section 52. When the first switch s1 is closed and the second switch s2 is open, the entire coil section 52 is connected to the circuit, resulting in a large inductance value. When the second switch s2 is closed and the first switch s1 is open, only the first half of the coil section 52 is connected to the circuit, resulting in a smaller inductance value. Therefore, the first switch s1 can be controlled to close or open according to the amplification gain requirements, thereby changing the connected inductance value and improving the flexibility of the feedback circuit.

[0092] In some embodiments, combined with Figure 8 and Figure 9 As shown, the coil section 52 includes a first coil 521 and a second coil 522. The first end of the first coil 521 is connected to the second end of the first connecting section 51. The second end of the first coil 521 is connected to the first end of the second coil 522 through the second connecting section. The second connecting section is connected to the ground terminal through the third switch s3. The second end of the second coil 522 is connected to the ground terminal through the fourth switch s4.

[0093] Specifically, the first connecting portion 51 can be an extension or a broken line segment. The first coil 521 and the second coil 522 are connected in series.

[0094] When the third switch S3 is open and the fourth switch S4 is closed, both the first coil 521 and the second coil 522 are connected to the circuit, resulting in a larger inductance value. When the third switch S3 is closed and the fourth switch S4 is open, only the first coil 521 is connected to the circuit, resulting in a smaller inductance value. Therefore, the third switch S3 and the fourth switch S4 can be controlled to open or close according to the amplification gain requirements, thereby changing the inductance value and improving the flexibility of the feedback circuit. Furthermore, by using two coils, the range of inductance value variation can be increased.

[0095] In some embodiments, when the distance between the coil portion 52 and the second extension portion 3 is greater than a first threshold and the first connecting portion 51 is perpendicular to the second extension portion 3, the connection position of the first connecting portion 51 and the second extension portion 3 is located at the center of the second extension portion 3.

[0096] Specifically, the first threshold can be set according to the actual magnetic field influence range of the coil portion 52. For example, the first threshold can be set to 500μm, 600μm, etc. When the distance between the coil portion 52 and the second extension portion 3 is greater than the first threshold and the first connecting portion 51 is perpendicular to the second extension portion 3, the influence of the coil portion 52 on the magnetic field of the first extension portion 1 and the third extension portion 4 is small, and the influence on both sides is basically the same. The coupling effect of the coil portion 52 on the first extension portion 1 and the third extension portion 4 can be ignored. Therefore, when the connection position of the first connecting portion 51 and the third extension portion 4 is located at the center position of the second extension portion 3, it can be ensured that the inductance value of the connection portion from the connection end on the first extension portion 1 to the second end of the inductor body 5 is equal to the inductance value of the connection portion from the connection end on the third extension portion 4 to the second end of the inductor body 5.

[0097] It should be understood that the distance between the coil portion 52 and the second extension portion 3 is the length of the projection of the line connecting the second end of the first connection portion 51 to the first end of the inductor body 5 in the first direction.

[0098] Combination Figure 13 and Figure 14As shown, when the distance between the coil portion 52 and the second extension portion 3 is greater than 600μm, and the magnetic field influence of the coil portion 52 on the first extension portion 1 and the third extension portion 4 is not considered, with an inductor transmission line width of 10μm and a distance S1 between the first extension portion 1 and the second extension portion 3 of 19μm, the distance between the first connection portion 51 and the first extension portion 1 is 58.21μm. The first extension portion and the third extension portion are symmetrically arranged. The inductance value of the feedback circuit is verified by simulation software. The distance from the first connection terminal Ls1 to... The inductance value L15 of the connection portion of the inductor body 5 is equal to 168.8288 pH, the inductance value L25 of the connection portion from the second connection terminal Ls2 to the inductor body 5 is equal to 168.4947 pH, the inductance value L35 of the connection portion from the third connection terminal Ls3 to the inductor body 5 is equal to 168.4515 pH, and the inductance value L45 of the connection portion from the fourth connection terminal Ls4 to the inductor body 5 is equal to 168.7755 pH. These can be considered as the inductance values ​​connected to the four connection terminals being equal.

[0099] In some embodiments, when the distance between the coil portion 52 and the second extension portion 3 is less than a second threshold, the connection position of the first connecting portion 51 and the second extension portion 3 is biased toward the first extension portion 1 or toward the third extension portion 4.

[0100] Specifically, the second threshold can be set according to the actual magnetic field influence range of the coil portion 52. For example, the second threshold can be set to 500μm, 600μm, etc. When the distance between the coil portion 52 and the second extension portion 3 is small, for example, less than 500μm, the magnetic field coupling of the coil portion 52 will cause the inductance value connected to the connection end on the first extension portion 1 to be different from the inductance value connected to the connection end on the third extension portion 4. Therefore, it is necessary to adjust the connection position of the first connection portion 51 and the second extension portion 3 to shift towards the first extension portion 1 or the third extension portion 4 so that the inductance value connected to the connection end on the first extension portion 1 and the inductance value connected to the connection end on the third extension portion 4 are the same.

[0101] When designing an inductor, first adjust the connection positions of the first connecting part 51 and the second extension part 3 so that the inductance value connected to the connection end on the first extension part 1 is equal to the inductance value connected to the connection end on the third extension part 4. Then adjust the distance between the first extension part 1 and the second extension part 3, as well as the distance between the second extension part 3 and the third extension part 4, so that the inductance value connected to the connection end on the first extension part 1 is the same, and the inductance value connected to the connection end on the third extension part 4 is the same. In other examples, the distance can be adjusted first and then the connection position can be adjusted.

[0102] Specifically, when the first connecting part 51 and the second extension part 3 are perpendicular and do not deflect, the offset direction of the connection position of the first connecting part 51 and the second extension part 3 is opposite to the current direction of the trace of the coil part 52 closest to the second extension part 3.

[0103] When the first connecting part 51 and the second extension part 3 are perpendicular, the trace closest to the second extension part 3 in the coil part 52 weakens the inductance value of the magnetic field coupling to the second extension part 3 opposite to it. Therefore, it is necessary to shift the connection position of the first connecting part 51 and the second extension part 3 in the opposite direction to the current direction of the trace closest to the second extension part 3 in the coil part 52 to counteract the weakening effect of the magnetic field coupling.

[0104] In one example, such as Figure 15 As shown, the first connecting part 51 and the second extension part 3 are perpendicular. The current direction of the trace closest to the second extension part 3 in the coil part 52 (i.e., the bottommost trace) is to the left (i.e., the current direction of the coil part 52 is clockwise). The distance S1 between the first extension part 1 and the second extension part 3 is 20μm, and the distance S2 between the third extension part 4 and the second extension part 3 is 21.8μm. The connection position of the first connecting part 51 and the second extension part 3 is offset to the right. When the distance between the first connecting part 51 and the first extension part 1 is 50μm, and the distance between the first connecting part 51 and the third extension part 4 is 45μm, the inductance value of the feedback circuit is verified by simulation software, and the simulation results are as follows. Figure 16 As shown, the inductance value L15 of the connection between the first connection terminal Ls1 and the inductor body 5 is equal to 387.5 pH, the inductance value L25 of the connection between the second connection terminal Ls2 and the inductor body 5 is equal to 387.2 pH, the inductance value L35 of the connection between the third connection terminal Ls3 and the inductor body 5 is equal to 387.1 pH, and the inductance value L45 of the connection between the fourth connection terminal Ls4 and the inductor body 5 is equal to 387.2 pH. These can be considered as the inductance values ​​connected to the four connection terminals being equal.

[0105] When the first connecting portion 51 deflects toward the first extension portion 1 or the third extension portion 4, the inductive coupling of the coil portion 52 will cause the inductance value connected to the connecting end on the first extension portion 1 to be different from the inductance value connected to the connecting end on the third extension portion 4. At this time, depending on the deflection direction of the first connecting portion 51 and the direction of current flow, shifting the connection position of the first connecting portion 51 and the second extension portion 3 toward the first extension portion 1 or the third extension portion 4 can also make the inductance value connected to the connecting end on the first extension portion 1 and the inductance value connected to the connecting end on the third extension portion 4 equal.

[0106] Specifically, when the current direction of the trace closest to the second extension 3 in the coil portion 52 is opposite to the current direction of the deflected extension, the connection position of the first connection portion 51 and the second extension 3 shifts away from the deflected extension. Here, the "deflected extension" refers to the extension (first extension 1 or third extension 4) that is closest to the coil portion 52 in the direction perpendicular to the second extension 3 after the first connection portion 51 is deflected.

[0107] According to the inductor layout requirements, the first connection portion 51 can be deflected toward the first extension portion 1 or the third extension portion 4. At this time, if the current direction of the trace closest to the second extension portion 3 in the coil portion 52 is opposite to the current direction of the deflected extension portion, the coupling effect of the coil portion 52 has a weakening effect on the inductance value connected to the connection terminal on the deflected extension portion. Therefore, the connection position of the first connection portion 51 and the second extension portion 3 is shifted away from the deflected extension portion to reduce the inductance value connected to the connection terminal on the deflected extension portion, ensuring that the inductance values ​​connected to the connection terminals on the two extension portions are equal.

[0108] like Figure 10 As shown, the first connecting part 51 deflects toward the third extension part 4, and the current in the coil part 52 closest to the second extension part 3 is opposite to that in the third extension part 4 (at this time, the current direction of the coil part 52 is clockwise). Inductive coupling weakens the inductance. The connection position of the first connecting part 51 and the second extension part 3 is shifted away from the deflected extension part, thereby making the inductance value connected to the connection end on the two extension parts equal.

[0109] In one example, the first connecting portion 51 is deflected and adjusted toward the third extension portion 4, such as... Figure 17 As shown, when the distance between the first connecting part 51 and the first extension part 1 is 45.5 μm, and the distance from the first connecting part 51 to the third extension part 4 is 50 μm, the inductance value of the feedback circuit is verified by simulation software, and the simulation results are as follows. Figure 18 As shown, the inductance value L25 of the connection portion from the second connection terminal Ls2 to the inductor body 5 is equal to 463.1 pH, and the inductance value L35 of the connection portion from the third connection terminal Ls3 to the inductor body 5 is equal to 463.4 pH. These can be considered as the inductance values ​​connected to the connection terminals on the first extension 1 and the third extension 4 being equal.

[0110] When the current direction of the trace closest to the second extension 3 in the coil section 52 is the same as the current direction of the deflected extension, the coupling effect of the coil section 52 enhances the inductance value connected to the connection terminal on the deflected extension. Therefore, the connection position of the first connection section 51 and the second extension 3 is shifted towards the direction closer to the deflected extension to reduce the inductance value connected to the connection terminal on the deflected extension and ensure that the inductance values ​​connected to the connection terminals on the two extensions are equal.

[0111] like Figure 11 As shown, when the current in the trace closest to the second extension 3 of the coil section 52 is the same as that in the deflected extension (at this time, the current direction of the coil section 52 is counterclockwise), the inductive coupling plays a role in enhancing the inductance, and the connection position of the first connection section 51 and the second extension 3 is shifted away from the deflected extension.

[0112] In this embodiment, the coil portion 52 cancels or enhances the magnetic field of the first extension portion 1 and / or the third extension portion 4. By biasing the connection position of the first connecting portion 51 and the second extension portion 3 toward the first extension portion 1 or toward the third extension portion 4, the magnetic field coupling effect of the coil portion 52 can be reduced by different connection distances on both sides, so that the inductance value of the connection portion from the connection end on the first extension portion 1 to the second end of the inductor body 5 is equal to the inductance value of the connection portion from the connection end on the third extension portion 4 to the second end of the inductor body 5.

[0113] This invention also provides a multi-port low-noise amplifier, such as... Figure 19 As shown, the multi-port low-noise amplifier includes at least two radio frequency input ports and a feedback circuit as described in any of the embodiments of the present invention. Each radio frequency input port is connected to a first amplification unit, and the sources of at least two first amplification units are respectively connected to at least two connection terminals in the feedback circuit.

[0114] Specifically, the first amplification unit adopts a transconductance amplification unit, which includes a first field-effect transistor. The gate of the first field-effect transistor is connected to the corresponding radio frequency input port RFN, and the source of the first field-effect transistor is connected to the corresponding connection terminal in the feedback circuit.

[0115] The multi-port low-noise amplifier also includes a common-source cascode amplifier unit. The drain of each first field-effect transistor is connected to the common-source cascode amplifier unit through a corresponding switching switch to achieve dual amplification.

[0116] The multi-port low-noise amplifier of this invention can make the inductance values ​​connected to the first amplification unit corresponding to different RF input ports equal, thus solving the problem of unbalanced inductance values ​​provided by the feedback circuit and reducing the difference in amplification gain between different RF input ports.

[0117] This invention also provides an RF front-end module, including a multi-port low-noise amplifier as described in the above embodiments of this invention.

[0118] This invention also provides a feedback circuit design method for optimizing any of the feedback circuits described in the above embodiments of this invention, including:

[0119] Adjust the distance between the first extension 1 and the second extension 3 so that the inductance values ​​of the connecting portions from at least two connection terminals on the first extension 1 to the inductor body 5 are equal.

[0120] Adjust the distance between the second extension 3 and the third extension 4 so that the inductance values ​​of the connection portions from at least two connection terminals on the third extension 4 to the inductor body 5 are equal.

[0121] Adjust the connection position of the first connecting part 51 and the second extension part 3 so that the inductance value of the connection portion from the connecting end on the first extension part 1 to the second end of the inductor body 5 is the same as the inductance value of the connection portion from the connecting end on the second extension part 3 to the second end of the inductor body 5.

[0122] It should be understood that the above steps may be performed in the following order: first, adjust the distance between the first extension 1 and the second extension 3 and adjust the distance between the second extension 3 and the third extension 4, and then adjust the connection position between the first connecting part 51 and the second extension 3; or first, adjust the connection position between the first connecting part 51 and the second extension 3, and then adjust the distance between the first extension 1 and the second extension 3 and adjust the distance between the second extension 3 and the third extension 4.

[0123] Based on the above steps, any of the feedback circuits in the above embodiments of the present invention can be optimized to ensure that the inductance values ​​connected to the connection terminal on the first extension 1 and the third extension 4 are equal, thereby solving the problem of unbalanced inductance values ​​provided by the feedback circuit and reducing the difference in amplification gain between different RF input ports.

[0124] While exemplary embodiments and their advantages have been described in detail, those skilled in the art can make various changes, substitutions and modifications to these embodiments without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined herein.

Claims

1. A feedback circuit applied to a multi-port low noise amplifier, characterized in that, The application relates to an inductor, which comprises a first extension, a second extension, a first connecting part and an inductor body. At least two connecting ends are arranged on the first extension at intervals, and different connecting ends are connected with different first amplification units corresponding to different radio frequency input ports of a multi-port low-noise amplifier. The two ends of the first connecting part are connected with one end of the first extension and the first end of the second extension, and the first extension and the second extension are oppositely arranged. The first end of the inductor body is connected with the second extension, and the second end of the inductor body is connected with a grounding end. The projection of any connecting end on the first extension along a first direction is located on the second extension, and the first direction is perpendicular to the extension direction of the second extension.

2. The feedback circuit of claim 1, wherein, The inductor further comprises a third extension and a second connecting part.

3. The feedback circuit of claim 1, wherein, At least two connecting ends are arranged on the third extension at intervals, and different connecting ends are connected with different first amplification units corresponding to different radio frequency input ports of a multi-port low-noise amplifier. The two ends of the second connecting part are connected with the second end of the second extension and one end of the third extension, and the second extension and the third extension are oppositely arranged. The first end of the inductor body is connected with the second extension, and the second end of the inductor body is connected with a grounding end.

4. The feedback circuit of claim 3, wherein, When the distance between the coil part and the second extension is greater than a first threshold value and the first connecting part is perpendicular to the second extension, the connecting position of the first connecting part and the second extension is located at the center position of the second extension.

5. The feedback circuit of claim 4, wherein, When the distance between the coil part and the second extension is less than a second threshold value, the connecting position of the first connecting part and the second extension is deviated towards the first extension or the third extension.

6. The feedback circuit of claim 4, wherein, The first connecting part is deviated towards the first extension or the third extension, the current direction of the wire closest to the second extension in the coil part is opposite to the current direction of the deviated extension, and the connecting position of the first connecting part and the second extension is deviated towards the direction away from the deviated extension.

7. The feedback circuit of claim 6, wherein, ​ 8. The feedback circuit of claim 6, wherein, ​ 9. The feedback circuit of claim 6, wherein, The first connecting part is deflected to the first extending part or the third extending part, the current direction of the wire of the coil part closest to the second extending part is the same as the current direction of the deflected extending part, and the connecting position of the first connecting part and the second extending part is offset to the direction close to the deflected extending part.

10. The feedback circuit of claim 4, wherein, The distance between the first extending part and the second extending part is between 15 μm and 25 μm.

11. The feedback circuit of claim 4, wherein, The second end of the coil part is connected with the ground end through a first switch, the third end of the coil part is connected with the ground end through a second switch, and the third end of the coil part is located between the first end of the coil part and the second end of the coil part.

12. The feedback circuit of claim 4, wherein, The coil part comprises a first coil and a second coil, the first end of the first coil is connected with the second end of the first connecting part, the second end of the first coil is connected with the first end of the second coil through a second connecting part, the second connecting part is connected with the ground end through a third switch, and the second end of the second coil is connected with the ground end through a fourth switch.

13. A multi-port low noise amplifier, characterized by, The feedback circuit comprises at least two radio frequency input ports and at least two first amplification units, each radio frequency input port is connected with one first amplification unit, and the sources of the at least two first amplification units are connected with at least two connecting ends in the feedback circuit respectively.

14. A radio frequency front end module, comprising: The multi-port low-noise amplifier comprises the multi-port low-noise amplifier according to claim 13.

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