Amplifier circuits and electronic equipment

Abstract

The present invention provides an amplifier circuit and an electronic device, wherein the amplifier circuit comprises: a transistor and a feedback oscillation module, wherein the gate of the transistor is connected to a signal to be processed, and the source of the transistor is directly or indirectly grounded; the drain of the transistor is directly or indirectly connected to an antenna port; and the feedback oscillation module is connected between the source and the gate of the transistor, and is used to provide feedback oscillation to the gate of the transistor according to a signal at the source of the transistor.

Description

Technical Field

[0001] The present invention relates to the field of signal processing, and in particular to an amplifier circuit and electronic equipment. Background Art

[0002] Bluetooth Low Energy (BLE) plays a crucial role in ultra-low power (ULP) radios within the Internet of Things (IoT). The power consumption of the power amplifier (PA) and mixer at the receiving end determines the total power consumption of the RF transceiver. Therefore, improving the efficiency of these PAs and mixers at high power levels is currently a key research topic.

[0003] In the prior art, a digitally controlled oscillator-power amplifier technology can be used to enable a power amplifier to be self-driven, thereby generating self-oscillation, thereby improving the overall transmission efficiency.

[0004] However, in the prior art, in a power amplifier using digital oscillator-power amplifier technology, since the circuit at the transistor gate is coupled with the circuit at the antenna, the resonance generated by the circuit is exposed to the antenna and is easily interfered with by the antenna. Summary of the Invention

[0005] The present invention provides an amplifier circuit and an electronic device to solve the problem that the resonance is exposed to the antenna and is easily interfered by the antenna.

[0006] According to a first aspect of the present invention, there is provided an amplifier circuit, comprising: a transistor and a feedback oscillation module, wherein the gate of the transistor is connected to a signal to be processed, and the source of the transistor is directly or indirectly grounded;

[0007] The drain of the transistor is directly or indirectly connected to the antenna port;

[0008] The feedback oscillation module is connected between the source and the gate of the transistor, and is used to provide feedback oscillation to the gate of the transistor according to the signal of the source of the transistor.

[0009] Optionally, the feedback oscillation module includes a feedback oscillation transformer, wherein the first end of the first side of the feedback oscillation transformer is connected to the source of the transistor, and the second end of the first side of the feedback oscillation transformer is grounded; the first end of the second side of the feedback oscillation transformer is connected to the gate of the transistor, and the second end of the second side of the feedback oscillation transformer is connected to a voltage source.

[0010] Optionally, the amplifier circuit also includes a first capacitor, and the feedback oscillation transformer includes a coupled first winding and a second winding; the first end of the first winding is connected to the source of the transistor, and the second end of the first winding is grounded; the first end of the second winding is connected to the gate of the transistor, and the second end of the second winding is connected to the voltage source, the first end of the first capacitor is connected to the source of the transistor, and the second end of the first capacitor is grounded.

[0011] Optionally, the amplifier circuit further includes a matching transformer;

[0012] The first end of the first side of the matching transformer is directly or indirectly connected to the drain of the transistor, the second end of the first side of the matching transformer is connected to the power supply end, and the second side of the matching transformer is connected to the antenna port.

[0013] Optionally, the amplifier circuit also includes a second capacitor, the matching transformer includes a coupled third winding and a fourth winding, the first end of the third winding is directly or indirectly connected to the drain of the transistor, the second end of the third winding is connected to the power supply end, the fourth winding is connected to the antenna port, and the second capacitor is connected in parallel to the fourth winding; the impedance provided by the third winding and the fourth winding is different.

[0014] Optionally, the amplifier circuit also includes a resonance point adjustment capacitor, the first end of the resonance point adjustment capacitor is connected to the second end of the second side of the feedback oscillation transformer, the second end of the resonance point adjustment capacitor is grounded, and the resonance adjustment capacitor is a variable capacitor.

[0015] Optionally, the amplifier circuit further includes a low noise amplifier, and the low noise amplifier is connected to the first side of the matching transformer;

[0016] When the antenna connected to the antenna port receives a signal, the antenna, the matching transformer and the low-noise amplifier form a receiving channel;

[0017] When the antenna transmits a signal, the transistor, the matching transformer and the antenna form a transmission channel.

[0018] Optionally, the amplifier circuit further includes a switching switch, wherein a first end of the switching switch is connected to an input side of the low-noise amplifier, a second end of the switching switch is connected to a first end of the third winding, and a third end of the switching switch is connected to a drain of the transistor; the switching switch is configured to:

[0019] The first end and the second end of the switching switch are connected to form the receiving channel, or the second end and the third end of the switching switch are connected to form the sending channel.

[0020] Optionally, the amplifier circuit further includes a control module, wherein the control module is electrically connected to the switching switch to control the switching switch to change the conduction state.

[0021] According to a second aspect of the present invention, an electronic device is provided, comprising the amplifier circuit according to the first aspect of the present invention and its optional solutions.

[0022] It can be seen that in the amplifier circuit and electronic device provided by the present invention, the oscillation feedback circuit and the matching circuit (such as a matching transformer) are isolated by a transistor. As a result, the oscillation feedback circuit at the transistor gate is no longer coupled with the circuit at the transistor drain (such as the winding in the matching transformer), and the corresponding resonance will no longer be interfered with by the antenna, which is conducive to ensuring accurate and stable signal transmission.

[0023] In a further embodiment of the present invention, a matching transformer can be combined with a low-noise amplifier to form a receiving channel, and can also be combined with a transistor to form a transmitting channel. This avoids the need for additional circuitry to form the receiving channel, reducing costs and board area, thus opening up more possibilities for selecting low-noise amplifiers. Furthermore, when forming the receiving channel, properly configuring the matching transformer to transform impedance can also increase the input gain of the amplifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic diagram of an amplifier circuit. Figure 1 ;

[0026] Figure 2 This is a schematic diagram of an amplifier circuit. Figure 2 ;

[0027] Figure 3 This is a schematic diagram of an amplifier circuit. Figure 3 ;

[0028] Figure 4 This is a schematic diagram of an amplifier circuit. Figure 4 ;

[0029] Figure 5 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 1 ;

[0030] Figure 6is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 2 ;

[0031] Figure 7 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 3 ;

[0032] Figure 8 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 4 ;

[0033] Figure 9 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 5 ;

[0034] Figure 10 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 6 ;

[0035] Figure 11 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 7 ;

[0036] Figure 12 is a schematic diagram of an amplifier circuit in one embodiment of the present invention Figure 8 ;

[0037] Description of reference numerals:

[0038] 1- Feedback oscillation module;

[0039] 11- Feedback oscillation transformer;

[0040] 2-antenna port;

[0041] 3-matching transformer;

[0042] 4-Low noise amplifier;

[0043] 5- Toggle switch;

[0044] a-first end;

[0045] b-second end;

[0046] c-third end;

[0047] 6-Control module;

[0048] 71-Oscillator;

[0049] 72-divider;

[0050] 73-buffer;

[0051] 74-power amplifier;

[0052] 75-power amplifier;

[0053] M0 - transistor;

[0054] M1 - transistor;

[0055] L1, L2, L3 - windings;

[0056] C1, C2, C3 - capacitors;

[0057] K1, K2, K3 - coupling factors;

[0058] kgs, kdo - coupling factors;

[0059] Lg-first winding;

[0060] Ls-second winding;

[0061] Ld-tertiary winding;

[0062] Lo-fourth winding;

[0063] Cs-first capacitor;

[0064] Co-second capacitor;

[0065] Cg-resonance adjustment capacitor;

[0066] Vdd-power supply terminal;

[0067] VGB - voltage source. DETAILED DESCRIPTION

[0068] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0069] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0070] The following specific embodiments are used to describe the technical solution of the present invention in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0071] In addition, the term "connection" in the specification and claims of the present invention refers to an electrical connection, which may include a direct connection or an indirect connection.

[0072] The present invention has fully studied various traditional amplifier circuits and their characteristics. To facilitate the demonstration of the beneficial effects of the embodiments of the present invention, the following will introduce circuit solutions that are different from the embodiments of the present invention to a certain extent. This does not mean that they are all prior art.

[0073] Due to the energy-saving advantages of open-loop modulation, all-digital phase-locked loops (ADPLLs) have widely adopted this technology. Among them, further reducing the flicker noise of the digital oscillator (DCO) can effectively improve the carrier frequency.

[0074] In the open-loop case, the TX architecture can be simplified to an independent oscillator (such as a voltage-controlled oscillator (VCO) or DCO) and a power amplifier (PA), which are also the two modules with the highest power consumption.

[0075] Please refer to Figure 1 , the input side of the oscillator 71 is connected to the supply voltage VDD vco The output side of the oscillator 71 is connected to the input side of the frequency divider 72, the output side of the frequency divider 72 is connected to the input side of the buffer 73, the output side of the buffer 73 is connected to the power amplifier 74, and the input side of the power amplifier 74 is connected to the supply voltage VDD PA .

[0076] Typically, oscillator 71 runs at twice the PA frequency to mitigate potential injection factors caused by parasitic coupling capacitance in the PA. Therefore, a cascaded frequency divider 72 and buffer 73 are required to drive a power amplifier 74 (i.e., the PA shown in the figure), where the power consumed by the PA does not decrease as the transmit (TX) output power decreases. However, at higher power backoff, the power consumed by the driver in the power amplifier is comparable to the target RF current (RF, Radio Frequency Communication) power, severely impacting the overall TX efficiency. By improving the module based on this structure, the overall TX efficiency is limited to 8% even at deep power backoff (-10dBm).

[0077] Please refer to Figure 2 The current-multiplexed PA-VCO architecture optimizes both into a single integrated system. However, this structure is incompatible with ultra-low voltage operating environments, primarily due to reduced voltage margins and output power limitations. Furthermore, the power distribution between the two PAs creates a trade-off between oscillator 71's PN and overall PA efficiency, hindering overall TX efficiency.

[0078] Please refer to Figure 3 and Figure 4 , relative current multiplexing TX topology technology, Figure 3 As shown, the utilization of the supply voltage VDD can be fully absorbed into the DCO-PA (i.e., the power amplifier 75), and the supply voltage VDD can be fully utilized, breaking the trade-off between PN and efficiency mentioned above, and fully adopting the passive (transformer) optimization technology. However, the six-port transformer that combines the oscillator resonant tank and the PA matching network (MN) will inevitably produce the disadvantage of mutual coupling between the two, as shown in FIG. Figure 4 As shown by the coupling factor k3 in , this Class F DCO-PA (i.e., power amplifier 75) is therefore very susceptible to antenna interference. Furthermore, to improve the efficiency of this Class F DCO-PA (i.e., power amplifier 75), the second impedance peak at the third harmonic may inevitably require off-chip filtering of HD3.

[0079] Please refer to Figure 4 , wherein the winding L1 and the winding L3 can be coupled with a coupling factor K2, and the winding L2 and the winding L3 can be coupled with a coupling factor K3. At the same time, the gate of the transistor M0 can be connected to the voltage source VGB through the winding L3 and the capacitor C3 respectively, and the drain of the transistor M0 can be connected to the power supply end through the winding L1 and the capacitor C1. The winding L2 can be connected in parallel with the capacitor C2, and the corresponding coupling can also be achieved by the coupling factor K1.

[0080] Although the DCO-PA architecture can eliminate the need for independent PA drive circuits for oscillators, dividers, and buffers, especially when the PA reaches power levels, its power consumption is difficult to reduce easily. Therefore, the DCO-PA architecture (especially in low-power solutions) can improve overall TX efficiency. In order to meet the oscillation criteria of the Barkhasusen criterion, a third winding L3 can be added, which produces another 180° loop phase shift through the anti-phase coupling between winding L3 and winding L1, thereby achieving feedback oscillation of the drain to gate (D to G) transformer. However, the coupling between winding L3 and winding L2, characterized by the coupling factor k3, will expose the resonant cavity to the antenna, making it susceptible to interference.

[0081] It can be seen that the above solutions cannot take into account both high TX efficiency and strong anti-interference ability. Therefore, in order to avoid Figure 4 In the shared six-port (i.e., three-winding) transformer of the amplifier shown, mutual coupling is caused by the forced coexistence of the oscillation loop and the impedance MN. An embodiment of the present invention proposes a single-ended structure MOS-DCO-PA based on source-to-gate (i.e., S-to-G) transformer feedback oscillation, which replaces the D-to-G feedback oscillation with S-to-G feedback. That is, the feedback oscillation module is isolated from the matching circuit through a transistor to enhance the isolation from the antenna to the DCO, breaking the trade-off between system efficiency and interference resilience.

[0082] Please refer to Figure 5 The amplifier circuit includes a transistor M1 and a feedback oscillation module 1, wherein the gate of the transistor M1 is connected to the signal to be processed, and the source of the transistor M1 is directly or indirectly grounded;

[0083] The drain of the transistor M1 is directly or indirectly connected to the antenna port 2;

[0084] The feedback oscillation module 1 is connected between the source and the gate of the transistor M1 , and is configured to provide feedback oscillation to the gate of the transistor M1 according to a signal at the source of the transistor M1 .

[0085] The signal to be processed may be understood as a radio frequency signal generated in a front-stage circuit of a transmitter, or a signal obtained by processing the radio frequency signal by other devices.

[0086] The amplifier circuit involved in the embodiment of the present invention can be understood as a part of the circuit that amplifies the signal, and it can be a separate chip or a part of a chip.

[0087] Please refer to Figure 6 The feedback oscillation module 1 includes a feedback oscillation transformer 11, a first end of a first side of the feedback oscillation transformer 11 is connected to the source of the transistor M1, and a second end of the first side of the feedback oscillation transformer 11 is grounded; a first end of a second side of the feedback oscillation transformer 11 is connected to the gate of the transistor M1, and a second end of the second side of the feedback oscillation transformer 11 is connected to a voltage source VGB.

[0088] The voltage source VGB can provide a bias for the transistor M1 , and the bias voltage provided to the transistor M1 can be changed by changing the size of the voltage source VGB, thereby controlling the on and off of the transistor M1 .

[0089] For an example, please refer to Figure 7The feedback oscillation transformer 11 includes a coupled first winding Lg and a coupled second winding Ls. The first winding Lg and the second winding Ls are coupled based on a coupling factor kgs. A first end of the first winding Lg is connected to the source of the transistor M1, and a second end of the first winding Lg is grounded. A first end of the second winding Ls is connected to the gate of the transistor M1, and a second end of the second winding Ls is connected to the voltage source VGB. A first end of the first capacitor Cs is connected to the source of the transistor M1, and a second end of the first capacitor Cs is grounded.

[0090] Among them, please refer to Figure 7 The amplifier circuit further includes a first capacitor Cs, a first end of the first capacitor Cs is connected to the source of the transistor M1, and a second end of the first capacitor Cs is grounded. In one embodiment, please refer to Figure 8 The amplifier circuit also includes a matching transformer 3, the first end of the first side of the matching transformer 3 is directly or indirectly connected to the drain of the transistor M1, the second end of the first side of the matching transformer 3 is connected to the power supply terminal Vdd, and the second side of the matching transformer 3 is connected to the antenna port 2.

[0091] Among them, please refer to Figure 8 The amplifier circuit also includes a second capacitor Co, the matching transformer 3 includes a coupled third winding Ld and a fourth winding Lo, the first end of the third winding Ld is directly or indirectly connected to the drain of the transistor M1, the second end of the third winding Ld is connected to the power supply terminal Vdd, the fourth winding Lo is connected to the antenna port 2, and the second capacitor Co is connected in parallel to the fourth winding Lo.

[0092] In one example, the impedance provided by the third winding Ld and the fourth winding Lo is different, and then, the power of the drain oscillation waveform is transmitted to the antenna to achieve power amplification through the appropriate impedance transformation ratio provided by the matching transformer 3 (the third winding Ld and the fourth winding Lo), wherein the third winding Ld and the fourth winding Lo are coupled based on the coupling factor kdo.

[0093] For further solutions, please refer to Figure 9 The amplifier circuit further includes a resonance adjustment capacitor Cg, a first end of the resonance point adjustment capacitor Cg is connected to the second end of the second side of the feedback oscillation transformer, and a second end of the resonance point adjustment capacitor Cg is grounded.

[0094] Among them, the resonance point adjustment capacitor Cg is used to adjust the resonant frequency of the amplifier circuit. In one example, the resonance point adjustment capacitor Cg is a variable capacitor. By changing the capacity of the resonance point adjustment capacitor Cg, the resonant frequency point of the amplifier circuit is changed.

[0095] It can be seen that the amplifier circuit provided by the present invention isolates the feedback oscillation circuit (for example, the feedback oscillation transformer 11) from the matching circuit (for example, the matching transformer 3) through the transistor M1. Furthermore, the feedback oscillation circuit at the gate of the transistor M1 is no longer coupled with the circuit at the drain of the transistor M1 (for example, the winding in the matching transformer 3), and the corresponding resonance will no longer be interfered with by the antenna, which is conducive to ensuring accurate and stable signal transmission.

[0096] Please refer to Figure 10 In one embodiment, the amplifier circuit further includes a low noise amplifier 4, which is connected to the first side of the matching transformer 3. In one example, the low noise amplifier 4 is connected to one end of the third winding Ld. In a further example, the low noise amplifier is a push-pull low noise amplifier.

[0097] Furthermore, when the antenna connected to the antenna port 2 receives a signal, the antenna, the matching transformer 3 and the low-noise amplifier 4 form a receiving channel; when the antenna sends a signal, the transistor M1, the matching transformer 3 and the antenna form a transmitting channel.

[0098] Therefore, in the embodiment of the present invention, matching transformer 3 can be combined with low-noise amplifier 4 to form a receiving channel, and can also be combined with transistor M1 to form a transmitting channel. This avoids the need for other circuits to form the receiving channel, reducing costs and board area, and providing more options for selecting low-noise amplifier 4. In addition, when forming the receiving channel, by properly configuring the impedance transformation of matching transformer 3, the input gain of the amplifier circuit can be increased.

[0099] During the specific implementation process, the size of the voltage source VGB can be changed, thereby changing the voltage provided to the gate of the transistor M1 to control the on and off of the transistor M1 to form a required path. For example: when sending a signal, the transistor M1 is turned on, and then the transistor M1, the matching transformer 3 and the antenna form a transmitting channel; when receiving a signal, the transistor M1 is turned off, and then the antenna, the matching transformer 3 and the low-noise amplifier 4 form a receiving channel.

[0100] In one example, the transistor M1 is an NMOS transistor. The voltage source VGB can be reduced, thereby reducing the bias voltage provided to the transistor M1, so as to control the transistor M1 to be turned off. At this time, the matching transformer 3, the second capacitor C0 and the low-noise amplifier 4 form a receiving channel; in other examples, the use of other transistors (such as triodes) to achieve similar functional conversion solutions is not excluded.

[0101] In one example, the transistor M1 is an NMOS transistor. By increasing the voltage source VGB, the bias voltage provided to the transistor M1 is increased to control the conduction of the transistor M1. In this case, through reasonable configuration, the transistor M1, the matching transformer 3, and the second capacitor Co form a transmission channel. In other examples, the use of other transistors (such as triodes) to achieve similar functional conversion is not excluded.

[0102] Further, in order to better implement the switching between the sending channel and the receiving channel, please refer to Figure 11 The amplifier circuit further includes a switch 5, wherein a first end a of the switch 5 is connected to the input side of the low noise amplifier 4, a second end b of the switch 5 is connected to the first end of the third winding Ld, and a third end c of the switch 5 is connected to the drain of the transistor M1. The switch 5 is used to:

[0103] The first end a and the second end b of the switching switch 5 are turned on (i.e., the matching transformer 3 and the low-noise amplifier 4 are turned on) to form a receiving channel, or the second end b and the third end c of the switching switch 5 are turned on (i.e., the transistor M1 and the matching transformer 3 are turned on) to form a transmitting channel.

[0104] The form of the switching switch 5 is not limited. No matter how the switching switch 5 is switched, as long as the switching of the switching switch 5 can enable the matching transformer 3 to form a receiving channel in combination with the low-noise amplifier 4 and to form a transmitting channel in combination with the transistor M1, it does not depart from the protection scope of this embodiment.

[0105] For further information, please refer to Figure 12 The amplifier circuit further includes a control module 6, which is electrically connected to the switching switch 5 (for example, it can be connected to the control end of the switching switch 5) to control the switching switch 5 to change the conduction state. The conduction state can refer to which end of the switching switch is conductive with which end, for example, it can include a conduction state in which the first end a of the switching switch is conductive with the second end b, and another conduction state in which the second end b of the switching switch is conductive with the third end c.

[0106] The control function may be implemented by the circuit hardware of the control module 6 , or by the combination of circuit hardware and software, or by software.

[0107] The present invention also provides an electronic device comprising the amplifier circuit of any of the above optional solutions.

[0108] The above electronic devices can be any electronic devices with communication functions, such as mobile phones, tablet computers, computers, smart wearable devices, network devices, vehicle-mounted devices, and other devices dedicated to or not dedicated to communication, etc.

[0109] In summary, the amplifier circuit provided by the present invention isolates the feedback oscillation circuit (for example, the feedback oscillation transformer 11) from the matching circuit (for example, the matching transformer 3) through the transistor M1. Furthermore, the feedback oscillation circuit at the gate of the transistor M1 is no longer coupled with the circuit at the drain of the transistor M1 (for example, the winding in the matching transformer 3), and the corresponding resonance will no longer be interfered with at the antenna, which is conducive to ensuring accurate and stable signal transmission.

[0110] In a further embodiment of the present invention, matching transformer 3 can be combined with low-noise amplifier 4 to form a receiving channel, and can also be combined with transistor M1 to form a transmitting channel. This avoids the need for additional circuitry to form the receiving channel, reducing costs and board area, and offering more options for selecting low-noise amplifier 4. Furthermore, when forming the receiving channel, properly configuring the impedance transformation of matching transformer 3 can also increase the input gain of the amplifier circuit.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An amplifier circuit, characterized in that: include: A transistor and a feedback oscillation module, wherein the gate of the transistor is connected to the signal to be processed, and the source of the transistor is directly or indirectly grounded; The drain of the transistor is directly or indirectly connected to the antenna port; The feedback oscillation module is connected between the source and the gate of the transistor, and is used to provide feedback oscillation to the gate of the transistor according to the signal of the source of the transistor; Wherein, the amplifier circuit further includes a matching transformer; The first end of the first side of the matching transformer is directly or indirectly connected to the drain of the transistor, the second end of the first side of the matching transformer is connected to the power supply end, and the second side of the matching transformer is connected to the antenna port; The amplifier circuit further includes a second capacitor, the matching transformer includes a coupled third winding and a fourth winding, a first end of the third winding is directly or indirectly connected to the drain of the transistor, a second end of the third winding is connected to the power supply end, the fourth winding is connected to the antenna port, and the second capacitor is connected in parallel to the fourth winding; the impedances provided by the third winding and the fourth winding are different; The feedback oscillation module includes a feedback oscillation transformer, wherein a first end of a first side of the feedback oscillation transformer is connected to a source of the transistor, and a second end of the first side of the feedback oscillation transformer is grounded; a first end of a second side of the feedback oscillation transformer is connected to a gate of the transistor, and a second end of a second side of the feedback oscillation transformer is connected to a voltage source.

2. The amplifier circuit according to claim 1, characterized in that It also includes a first capacitor, and the feedback oscillation transformer includes a coupled first winding and a second winding; the first end of the first winding is connected to the source of the transistor, and the second end of the first winding is grounded; the first end of the second winding is connected to the gate of the transistor, and the second end of the second winding is connected to the voltage source, the first end of the first capacitor is connected to the source of the transistor, and the second end of the first capacitor is grounded.

3. The amplifier circuit according to claim 1 or 2, characterized in that: It also includes a resonance point adjustment capacitor, a first end of the resonance point adjustment capacitor is connected to the second end of the second side of the feedback oscillation transformer, a second end of the resonance point adjustment capacitor is grounded, and the resonance adjustment capacitor is a variable capacitor.

4. The amplifier circuit according to claim 1 or 2, characterized in that: Also included is a low noise amplifier connected to the first side of the matching transformer; When the antenna connected to the antenna port receives a signal, the antenna, the matching transformer and the low-noise amplifier form a receiving channel; When the antenna sends a signal, the transistor, the matching transformer and the antenna form a transmission channel.

5. The amplifier circuit according to claim 4, characterized in that The device further comprises a switching switch, wherein a first end of the switching switch is connected to an input side of the low noise amplifier, a second end of the switching switch is connected to a first end of the third winding, and a third end of the switching switch is connected to a drain of the transistor, and the switching switch is used to: The first end and the second end of the switching switch are turned on to form the receiving channel, or the second end and the third end of the switching switch are turned on to form the sending channel.

6. The amplifier circuit according to claim 5, characterized in that It also includes a control module, which is electrically connected to the switch to control the switch to change the conduction state.

7. An electronic device, characterized in that: The amplifier circuit comprises the amplifier circuit according to any one of claims 1 to 6.

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