Integrated radio frequency transceiver switch structure of fusion doherty power amplifier and radio frequency front end

Abstract

This invention provides an integrated RF transceiver switch structure and RF front-end that incorporates a Doherty power amplifier, relating to the field of RF transceiver front-end technology. The integrated RF transceiver switch structure includes primary coils of two Doherty power amplifiers, a secondary coil of a single low-noise amplifier, a common coil, and a MOSFET. One end of the differential output port of the common coil is connected to an external antenna. The primary coils of the two Doherty power amplifiers are coupled to the common coil. The secondary coil of the single low-noise amplifier is coupled to the common coil. When the MOSFET is in the ON state, the secondary coil of the low-noise amplifier is short-circuited and mismatched with the common coil. When the MOSFET is in the OFF state, the secondary coil of the low-noise amplifier is matched with the common coil. This invention achieves an integrated design of the matching structure and switch of the transformer-synthesized two-channel Doherty power amplifier and the single-channel common-source low-noise amplifier, effectively reducing the insertion loss of the RF switch structure.

Description

Technical Field

[0001] This invention relates to the field of radio frequency transceiver front-end technology, specifically to an integrated radio frequency transceiver switch structure and radio frequency front-end that incorporates a Doherty power amplifier. Background Technology

[0002] With the development of mobile communication technology, a situation has emerged where multiple mobile communication standards coexist. Due to the advent of the 5G era, the modulation modes of radio frequency signals are more complex, and the linearity requirements are higher. Existing on-chip transceiver switches mostly adopt transistor-based series-parallel switching structures, which are independent circuit modules with relatively large insertion losses. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides an integrated RF transceiver switch structure and RF front-end that incorporates a Doherty power amplifier, solving the technical problem of high insertion loss in existing RF switch structures.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides an integrated RF transceiver switch structure incorporating a Doherty power amplifier, comprising primary coils of two Doherty power amplifiers, a secondary coil of a single low-noise amplifier, a common coil, and a MOSFET.

[0008] The differential output port of the common coil is connected to an external antenna. The primary coils of the two Doherty power amplifiers are coupled to the common coil. The secondary coil of the single low-noise amplifier is coupled to the common coil.

[0009] The source and drain of the MOSFET are bridged on the transmission lines at both ends of the differential port of the secondary coil of the single-channel low-noise amplifier, and the gate is connected to an external control signal. When the MOSFET is in the on state, the secondary coil of the low-noise amplifier is short-circuited and mismatched with the common coil. When the MOSFET is in the off state, the secondary coil of the low-noise amplifier is matched with the common coil.

[0010] Preferably, the common coil includes two turns of winding, wherein the first turn of winding serves as the primary coil of the differential common-source low-noise amplifier, and the first turn of winding and the second turn of winding serve as the secondary coils of the power combining network of the two Doherty power amplifiers.

[0011] Preferably, the primary coils of the two Doherty power amplifiers are stacked on top of the common coil, and the secondary coil of the single low-noise amplifier is arranged in a staggered manner on the same layer as the primary coils of the two power amplifiers.

[0012] Preferably, the center point of a section of metal transmission line between the secondary coil of the single-channel low-noise amplifier and the differential output port of the common coil is used as a radio frequency virtual point for connecting to an external bias.

[0013] Preferably, the differential port of the secondary coil of the single-channel low-noise amplifier is connected to the differential input terminal of the low-noise amplifier.

[0014] Preferably, the primary coils of the two Doherty power amplifiers are symmetrical to each other, and the differential ports of the primary coils of the two Doherty power amplifiers face the left and right sides of the common coil, respectively. Where the metal of the two primary coils intersects in the same layer, they are arranged in a cross-layer metal bridging manner.

[0015] Preferably, the differential ports of the primary coils of the two Doherty power amplifiers are respectively connected to the differential output terminals of the main power amplifier and the auxiliary power amplifier; the center point of the two sets of coils is a radio frequency virtual point used to connect to a DC power supply.

[0016] Preferably, an adjustable capacitor is connected to each transmission line of the differential port of the primary coil of the two Doherty power amplifiers to achieve asymmetric matching of the final stage synthesis network of the Doherty power amplifier.

[0017] Secondly, the present invention provides a radio frequency front-end, the radio frequency front-end including an integrated radio frequency transceiver switch structure that integrates a Doherty power amplifier as described above.

[0018] (III) Beneficial Effects

[0019] This invention provides an integrated RF transceiver switch structure and RF front-end that incorporates a Doherty power amplifier. Compared with the prior art, it has the following advantages:

[0020] The integrated RF transceiver switch structure of this invention includes primary coils of two Doherty power amplifiers, a secondary coil of a single low-noise amplifier, a common coil, and a MOSFET. The differential output port of the common coil is connected to an external antenna. The primary coils of the two Doherty power amplifiers are coupled to the common coil. The secondary coil of the single low-noise amplifier is also coupled to the common coil. The source and drain of the MOSFET are bridged on the transmission lines at both ends of the differential port of the secondary coil of the single low-noise amplifier, and the gate is connected to an external control signal. When the MOSFET is in the ON state, the secondary coil of the low-noise amplifier is short-circuited and mismatched with the common coil. When the MOSFET is in the OFF state, the secondary coil of the low-noise amplifier is matched with the common coil. This invention provides an integrated RF transceiver switch structure that integrates the matching network of two Doherty power amplifiers and a differential common-source low-noise amplifier, solving the technical problem of high insertion loss in existing RF switch structures. It achieves an integrated design of Doherty power amplifier, low-noise amplifier, and transceiver switch based on transformer synthesis in the RF front-end, effectively improving integration and reducing insertion loss. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0022] Figure 1 This is a schematic diagram of the integrated radio frequency transceiver switch structure in an embodiment of the present invention;

[0023] Figure 2 This is a three-dimensional model diagram of the multilayer transformer coil of the integrated radio frequency transceiver switch structure in an embodiment of the present invention;

[0024] Figure 3 This is a three-dimensional model diagram of an embodiment of the present invention that does not include a common-source low-noise amplifier coil;

[0025] Figure 4 This is a schematic diagram of the integrated RF transceiver switch structure in the transmission mode, as shown in the embodiment.

[0026] Figure 5 This is a 3D model diagram of the embodiment that does not include the Doherty power amplifier coil;

[0027] Figure 6 This is a schematic diagram of the integrated RF transceiver switch structure in the receiving mode, as shown in the embodiment.

[0028] Among them, 11-antenna port, 12-auxiliary power amplifier differential port, 13-main power amplifier differential port, 14-low noise amplifier differential port, 21-primary coil of the final stage power combiner of the main power amplifier, 22-primary coil of the final stage power combiner of the auxiliary power amplifier, 23-main power amplifier RF virtual ground, connected to power supply, 24-auxiliary power amplifier RF virtual ground, connected to power supply, 25-ground plane, 31-common balun coil, 32-secondary coil of the low noise amplifier, 33-cross-layer metal wire, 34-low noise amplifier virtual ground, connected to external bias, 35-ground plane. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0030] This application provides an integrated RF transceiver switch structure that incorporates a Doherty power amplifier, solving the technical problem of high insertion loss in existing RF switch structures. It achieves an integrated design of the matching structure and switch of a transformer-synthesized two-channel Doherty power amplifier and a single-channel common-source low-noise amplifier, effectively reducing the insertion loss of the RF switch structure.

[0031] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0032] Doherty power amplifiers are widely used to improve the transmission efficiency of RF circuits. Existing transformer-combined Doherty power amplifiers typically use two sets of asymmetrical discrete coils connected in series as a power combining matching network to achieve active load modulation of the main and auxiliary power amplifiers. In this structure, the primary coils of the power combining network of the two power amplifiers are symmetrically laid out in the same plane, forming a network with the secondary coils. This power combining network is relatively large, has a low coupling coefficient, and consequently reduces output power and efficiency. The secondary coils of this power combining network are also large and irregularly shaped. If a common matching design is implemented with the coils of a low-noise amplifier (LNOA), the secondary coil of the LNOA's input matching transformer will also be too large, introducing significant parasitic resistance. Furthermore, the irregular shape will create additional parasitic coupling between the coupled transmission lines, both of which worsen the impedance and noise matching of the LNOA. Typically, the transceiver front-end of a Doherty power amplifier requires an additional switching module to switch between the receive and transmit channels. Traditional RF switching modules require integrating numerous switching paths, resulting in high insertion loss and poor power capacity.

[0033] To address the aforementioned issues, this invention proposes an integrated RF transceiver switch structure that combines a Doherty power amplifier and a common-source low-noise amplifier matching network.

[0034] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0035] This invention provides an integrated RF transceiver switch structure that incorporates a Doherty power amplifier, comprising: primary coils of two Doherty power amplifiers, secondary coils of a single low-noise amplifier, a common coil, and a MOSFET.

[0036] In this configuration, one end of the differential output port of the common coil is connected to an external antenna. The primary coils of the two Doherty power amplifiers are coupled to the common coil. The secondary coil of the single-channel low-noise amplifier is also coupled to the common coil. The source and drain of the MOSFET are bridged on the transmission lines at both ends of the differential port of the secondary coil of the single-channel low-noise amplifier, and the gate is connected to an external control signal. When the MOSFET is in the ON state, the secondary coil of the low-noise amplifier is short-circuited and mismatched with the common coil. When the MOSFET is in the OFF state, the secondary coil of the low-noise amplifier is matched with the common coil.

[0037] This invention provides an integrated RF transceiver switch structure that combines a matching network of two Doherty power amplifiers and a differential common-source low-noise amplifier. This solves the technical problem of high insertion loss in existing RF switch structures and realizes an integrated design of Doherty power amplifier, low-noise amplifier and transceiver switch based on transformer synthesis in the RF front end, effectively improving integration and reducing insertion loss.

[0038] The schematic diagram of the integrated radio frequency switch structure of this invention is shown below. Figure 1 As shown, different types of lines represent different metal layers. A long dashed line represents a two-turn balun coil, i.e., a common coil. Where the coil lines intersect, a short dashed line represents a metal transmission line bridging to the adjacent next layer via a via. A long solid line represents two symmetrical sets of single-turn coils. Where the coils intersect, a dotted line represents a metal transmission line bridging to the adjacent next layer via a via. The metal transmission line represented by the long solid line is located directly above the metal transmission line represented by the long dashed line. The outermost long solid line is staggered with the two inner sets of long solid lines on the same layer, without any metal layer intersections.

[0039] like Figures 1-6As shown, this embodiment of the invention includes four sets of transformer coils, one set of MOSFETs, and two sets of adjustable capacitors. The antenna winding is a two-turn balun coil, which is a common coil connected to the external antenna. The common coil serves as the secondary coil of the Doherty power amplifier power combining network based on transformer combining and the primary coil of the differential common-source low-noise amplifier. All intersections between the coil windings are avoided using connections similar to 13-layer metal wire.

[0040] Located directly above the common coil are two sets of single-turn winding coils symmetrical about the common coil. The differential ports of the two sets of coils face the left and right sides of the common coil, respectively. Where one set of coils intersects with the other set of coils in the same metal layer, a cross-layer metal bridge is used instead. These two sets of coils are respectively connected to the final stage amplifiers of the main and auxiliary circuits of the Doherty power amplifier. The center point of the two sets of coils is the radio frequency virtual point, which is used to connect to the DC power supply.

[0041] The secondary coil of the common-source differential low-noise amplifier and the primary coil of the Doherty power amplifier are arranged in a staggered manner on the same plane. The diameter of the coil is larger than that of the common coil and it is a single-turn winding coil. The center point of a section of metal transmission line between the coil and the differential output port of the balun coil is a radio frequency virtual point used to connect to an external bias.

[0042] Figure 4 In transmit mode, a bias voltage is applied to the gate of the MOSFET. At this time, the MOSFET is in the on state, the secondary coil of the low noise amplifier is shorted and mismatched with the common coil, and the final stage power amplifier of the power amplifier is in the matched state. Figure 6 In receive mode, the gate of the switching MOSFET has no bias voltage, the MOSFET is in the off state, and the secondary coil of the low-noise amplifier is matched with the common coil.

[0043] This invention also provides a radio frequency front-end, which includes an integrated radio frequency transceiver switch structure that incorporates a Doherty power amplifier as described above.

[0044] In summary, compared with existing technologies, it has the following beneficial effects:

[0045] 1. This invention provides an integrated RF transceiver switch structure that integrates a matching network of two asymmetric Doherty power amplifiers and a differential common-source low-noise amplifier. This solves the technical problem of high insertion loss in existing RF switch structures and realizes an integrated design of Doherty power amplifier, low-noise amplifier and transceiver switch based on transformer synthesis in the RF front end, effectively improving integration and reducing insertion loss.

[0046] 2. The coil-multiplexed input-output common-matching structure of this invention effectively reduces the area of ​​the matching network, improves the coupling coefficient of the power combining network, and reduces the loss of the passive matching network. Ultimately, it can effectively improve the output power and efficiency of the transmit link and the noise performance of the receive link.

[0047] 3. In the embodiments of the present invention, the two primary coils of the Doherty power amplifier are symmetrically crossed, and the overlapping metal wires are connected by cross-layer metal bridging, which effectively solves the problem of large size and low coupling coefficient of series power combining network, making the output power combining matching network of Doherty power amplifier more compact and easier to integrate; and the introduction of adjustable capacitors realizes the asymmetric matching of the final stage combining network of Doherty power amplifier.

[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 invention.

Claims

1. An integrated RF transceiver switch structure incorporating a Doherty power amplifier, characterized in that, This includes the primary coils of two Doherty power amplifiers, the secondary coils of a single low-noise amplifier, a common coil, and a MOSFET. The differential output port of the common coil is connected to an external antenna. The primary coils of the two Doherty power amplifiers are coupled to the common coil. The secondary coil of the single low-noise amplifier is coupled to the common coil. The source and drain of the MOSFET are bridged on the transmission lines at both ends of the differential port of the secondary coil of the single-channel low-noise amplifier, and the gate is connected to an external control signal. When the MOSFET is in the on state, the secondary coil of the single-channel low-noise amplifier is short-circuited and mismatched with the common coil. When the MOSFET is in the off state, the secondary coil of the single-channel low-noise amplifier is matched with the common coil. The common coil includes two turns of winding, wherein the first turn of winding serves as the primary coil of a single-channel low-noise amplifier, and the first and second turns of winding serve as the secondary coils of a power combining network for two-channel Doherty power amplifiers.

2. The integrated RF transceiver switch structure incorporating a Doherty power amplifier as described in claim 1, characterized in that, The primary coils of the two Doherty power amplifiers are stacked on top of the common coil, and the secondary coil of the single low-noise amplifier is arranged in a staggered manner on the same layer as the primary coils of the two Doherty power amplifiers.

3. The integrated RF transceiver switch structure incorporating a Doherty power amplifier as described in claim 1, characterized in that, The secondary coil of the single-channel low-noise amplifier has a metal transmission line with its center point located at the differential output port of the common coil as a radio frequency virtual point, which is used to connect to an external bias.

4. The integrated RF transceiver switch structure incorporating a Doherty power amplifier as described in claim 1, characterized in that, The differential port of the secondary coil of the single-channel low-noise amplifier is connected to the differential input terminal of the low-noise amplifier.

5. The integrated RF transceiver switch structure with Doherty power amplifier as described in any one of claims 1 to 4, characterized in that, The primary coils of the two Doherty power amplifiers are symmetrical to each other. The differential ports of the primary coils of the two Doherty power amplifiers face the left and right sides of the common coil, respectively. Where the metal of the two primary coils intersects in the same layer, they are arranged in a cross-layer metal bridging manner.

6. The integrated RF transceiver switch structure incorporating a Doherty power amplifier as described in claim 5, characterized in that, The differential ports of the primary coils of the two Doherty power amplifiers are respectively connected to the differential output terminals of the main power amplifier and the auxiliary power amplifier; the center point of the two sets of coils is the radio frequency virtual ground point, which is used to connect to the DC power supply.

7. The integrated RF transceiver switch structure incorporating a Doherty power amplifier as described in claim 5, characterized in that, An adjustable capacitor is connected to each transmission line of the differential port of the primary coil of the two Doherty power amplifiers to achieve asymmetric matching of the final stage synthesis network of the Doherty power amplifier.

8. A radio frequency front end, characterized in that, The radio frequency front end includes an integrated radio frequency transceiver switch structure that incorporates a Doherty power amplifier as described in any one of claims 1 to 7.

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