Multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit

Abstract

The invention discloses a multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit, and belongs to the technical field of microwave integrated circuits. Switching between the ultra wide band and multiple communication frequency bands can be realized by adjusting the control voltage and the drain electrode power supply circuit of the pre-stage circuit, and the center frequency of the communication frequency bands can be independently designed. And the center frequency of the communication frequency band can be changed by changing the values of the capacitor and the inductor in the continuous adjustable branch knot and the inductor in the drain power supply circuit of the pre-stage circuit. Through on-chip voltage and external voltage switching control, mode switching of the ultra wide band and multiple communication frequency bands can be realized, and the problems that the ultra wide band and the communication frequency bands of the high-performance power amplifier can be switched and the communication frequency is continuously adjustable are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave integrated circuits, and in particular relates to a multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit for electronic warfare systems and multi-band communication systems. Background Art

[0002] In 2023, Liu Shuang et al. from Chongqing University in China designed a multi-mode power amplifier based on a three-way reverse gate biased Doherty architecture. The amplifier can operate in three narrowband communication modes: 1.85 GHz, 1.18 GHz / 2.53 GHz, and 0.73 GHz / 2.37 GHz, with an output power greater than 44.2 dBm. However, this is limited to switching between several narrower communication bands and cannot cover ultra-wideband operation. See [S. Liu et al., "Triple-Mode Reciprocal Doherty Power Amplifier With Multi-Band Operation and Extended High Efficiency Range," in IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 70, no. 5, pp. 1928-1939, May 2023, doi: 10.1109 / TCSI.2023.3242693.].

[0003] In 2024, Zhu Shiquan and others from the University of Electronic Science and Technology of China used an adjustable output matching network and ultra-wideband input and inter-stage matching network to design a 6-18GHz power amplifier that can switch between the 6-18GHz electronic warfare mode and the 12-14GHz satellite communication mode. This is also the first reported high-power GaN MMIC PA that can perform mode switching. However, the technology is not yet mature, and the power amplifier has only been simulated and has not yet been verified on the wafer. See [Zhu Shiquan. Research on 6-18GHz dual-mode high-power gallium nitride power amplifier chip [D]. University of Electronic Science and Technology of China, 2024. DOI: 10.27005 / d.cnki.gdzku.2024.000557.].

[0004] It can be seen that the current multi-mode power amplifier design can only switch between several narrow frequency bands or an ultra-wideband band and a narrow frequency band. The main technologies include dual-band matching networks, coupled line / duplexer forms, reverse gate bias Doherty architecture, adjustable matching networks, etc. However, there are no reports on power amplifiers that can simultaneously cover the ultra-wideband operation required by electronic warfare and the multiple narrowband operating modes required by communications. Summary of the Invention

[0005] In order to solve the multi-mode operation problem of the power amplifier in ultra-wideband and multiple communication frequency bands, the present invention proposes a circuit design method, which can achieve switchability between ultra-wideband and communication frequency bands and continuously adjustable communication frequency while ensuring high performance of the power amplifier.

[0006] The technical solutions adopted in the present invention are as follows:

[0007] A multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit, comprising a front-stage amplifier circuit, a mode switching circuit, a rear-stage amplifier circuit and continuously adjustable branches;

[0008] The pre-amplifier circuit includes: a DC blocking capacitor C B1 , stabilizing resistor R in , isolation resistor RG1, inductor L0, mode switching capacitor C BS1 , control switching transistor Q s1 , gate supply inductor L G , transistor Q0, decoupling capacitor C de1 , the first continuously adjustable branch, output matching inductor L1, DC blocking capacitor C B2 , drain power supply circuit; the DC blocking capacitor C B1 One end is used as the input of the pre-amplifier circuit, and the other end is connected to the stabilizing resistor R in , mode switching capacitor C BS1 , input matching inductor L0, gate supply inductor L G , isolation resistor RG1, decoupling capacitor C de1 , decoupling capacitor C de1 The other end of the ground is connected to the decoupling capacitor C de1 The common point is connected to the DC power supply V gs1 , input matching inductor L0 and gate supply inductor L G The common point of the first continuously adjustable branch and the gate of the transistor Q0 are additionally connected, and the stabilizing resistor R in and mode switching capacitor C BS1 The common point of the control switch transistor Q s1 The source of the mode switching capacitor C BS1 The common point with the input matching inductor L0 is connected to the control switch transistor Q s1 The drain of the switching transistor Q s1 The gate is connected to the control voltage V dp The source of transistor Q0 is grounded, and the drain is connected to one end of the output matching inductor L1. The other end of the output matching inductor L1 is connected to the DC blocking capacitor C. B2 One end of the DC blocking capacitor C B2 The other end is used as the output of the pre-stage circuit; the output is matched with the inductor L1 and the DC blocking capacitor C B2 A drain power supply circuit is connected therebetween;

[0009] A mode switching circuit is provided between the pre-stage amplifier circuit and the post-stage amplifier circuit;

[0010] The post-amplifier circuit includes: a first matching microstrip line MLIN1, an inductor L g , the second matching microstrip line MLIN2, the third matching microstrip line MLIN3, three RC parallel networks, the drain matching inductor L d , fourth matching microstrip line MLIN4, fifth matching microstrip line MLIN5, sixth matching microstrip line MLIN6, isolation resistor R G2 , mode switching resistor R GS2 and the corresponding control switch transistor Q s4 , decoupling capacitor C de3 and C de4 , the first LC series resonant network, the switching transistor Q s5 , the second LC series resonant network, the DC blocking capacitor C B3 , isolation inductance L D2 , transistors Q1, Q2, Q3; one end of the first matching microstrip line MLIN1 is used as the input end of the post-amplifier circuit, and the other end is connected to the inductor L in sequence g , the second matching microstrip line MLIN2, the third matching microstrip line MLIN3, the isolation resistor R G2 , decoupling capacitor C de3 , decoupling capacitor C de3 The end of the first matching microstrip line MLIN1 and the inductor L g The middle of the second continuously adjustable branch and one end of the first RC parallel network are connected. The other end of the first RC parallel network is connected to the gate of the transistor Q1. The drain of the transistor Q1 is connected to the drain matching inductor L in turn. d , fourth matching microstrip line MLIN4, fifth matching microstrip line MLIN5, sixth matching microstrip line MLIN6, DC blocking capacitor C B3 , DC blocking capacitor C B3 The end of is the output end; the inductor L g The middle of the second matching microstrip line MLIN2 is connected to the third continuously adjustable branch and one end of the second RC parallel network. The other end of the second RC parallel network is connected to the gate of the transistor Q2. The drain of the transistor Q2 is connected to the matching inductor L. d The middle of the fourth matching microstrip line MLIN4; the middle of the second matching microstrip line MLIN2 and the third matching microstrip line MLIN3 is connected to the fourth continuously adjustable branch and one end of the third RC parallel network, the other end of the third RC parallel network is connected to the gate of the transistor Q3, and the drain of the transistor Q3 is connected to the middle of the fourth matching microstrip line MLIN4 and the fifth matching microstrip line MLIN5; the third matching microstrip line MLIN3 and the isolation resistor R G2The middle is connected to the switching transistor Q s4 The source of the switching transistor Q s4 The gate of the switching transistor Q is connected to the control voltage V0. s4 The drain-connected mode switching resistor R GS2 One end of the mode switching resistor R GS2 The other end is connected to the isolation resistor R G2 With the decoupling capacitor C de3 The common node of the fifth matching microstrip line MLIN5 and the sixth matching microstrip line MLIN6 is connected to one end of the first LC series resonant network, and the other end of the first LC series resonant network is grounded; the sixth matching microstrip line MLIN6 is connected to the DC blocking capacitor C B3 The middle of the second LC series resonant network is connected to one end, and the other end of the second LC series resonant network is connected to the switching transistor Q s5 The source of the switching transistor Q s5 The gate is connected to the control voltage V H , switching transistor Q s5 The drain of the sixth matching microstrip line MLIN6 is grounded; the DC blocking capacitor C B3 The decoupling capacitor C is connected in the middle de4 One end and the isolation inductor L D2 One end of the decoupling capacitor C de4 The other end of the ground, the isolation inductor L D2 One end is connected to a DC power supply V ds2 .

[0011] The first LC series resonant network and the second LC series resonant network have the same structure, which is a series structure of an inductor and a capacitor.

[0012] Furthermore, the first continuously adjustable branch, the second continuously adjustable branch, the third continuously adjustable branch, and the fourth continuously adjustable branch have the same structure and all include: a control switch transistor Q sc , capacitor C c 、Inductor L c , four reconfigurable capacitors C cn , four switching transistors Q scn , n=1,2,3,4; control switch transistor Q sc The source of the control switch transistor Q sc The gate is connected to the control voltage V c , controls the switching transistor Q sc The drain connection capacitance C c One end of the capacitor C c The other end is connected to the switching transistor Q scn The source and inductor L c One end of the switching transistor Q scnThe gates of the cn , switching transistor Q scn The drains of the capacitors C are connected one by one. cn One end of the capacitor C forms a reconfigurable capacitor group consisting of four reconfigurable capacitors; cn The other end of the inductor L c The connection serves as the input end of the continuously adjustable branch.

[0013] Furthermore, the drain power supply circuit is a two-way power supply connected in parallel, one of which is connected in turn to the inductor L D1,1 , decoupling capacitor C de2,1 To ground, inductor L D1,1 With the decoupling capacitor C de2,1 Connect a DC power supply V ds1,1 , the other one is connected to the inductor L D1 , decoupling capacitor C de2,2 To ground, inductor L D1,2 With the decoupling capacitor C c2,2 Connect a DC power supply V ds1,2 .

[0014] Furthermore, the mode switching circuit includes: a DC blocking capacitor C B2 , mode switching inductor L2 and corresponding control switch transistor Q s2 , mode switching capacitor C BS2 and the corresponding control switch transistor Q s3 ; The mode switching circuit starts from the input end and connects the DC blocking capacitor C B2 , mode switching inductor L2, mode switching capacitor C BS2 , DC blocking capacitor C B2 Connect the switching transistor Q between the mode switching inductor L2 s2 The source of the mode switching inductor L2 and the mode switching capacitor C BS2 Connected to the switching transistor Q s2 The drain of the switching transistor Q s3 The source of the switching transistor Q s2 The gate is connected to the control voltage V Z ;Switching transistor Q s3 The gate is connected to the control voltage V dp , mode switching capacitor C BS2 With the switching transistor Q s3 The drains are connected in common as the output end of the mode switching circuit.

[0015] The present invention proposes a multimode microwave power amplifier circuit with switchable ultra-wideband and communication bands, and continuously adjustable communication frequency. Switching between ultra-wideband and multiple communication bands is achieved by adjusting the control voltage and the drain power supply circuit of the preceding circuit. The center frequency of the communication band can be independently designed, and the center frequency of the communication band can be changed by varying the values ​​of the capacitor and inductor in the continuously adjustable branch and the inductor in the drain power supply circuit of the preceding circuit. Mode switching between ultra-wideband and multiple communication bands is achieved through on-chip voltage and external voltage switching control, solving the problem of high-performance power amplifiers with switchable ultra-wideband and communication bands and continuously adjustable communication frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the amplifier circuit and mode switching circuit in Example 1 of the present invention, connected to the continuously adjustable branch through the "△" terminal;

[0017] Figure 2 This is a schematic diagram of the continuously adjustable branch in Example 1 of the present invention, which is connected to the amplifier circuit and the mode switching circuit via the "△" terminal;

[0018] Figure 3 This is a diagram of the output power simulation results of Example 1 of the present invention;

[0019] Figure 4 This is a diagram showing the power added efficiency simulation results of Example 1 of the present invention. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in conjunction with the following specific embodiments and with reference to the accompanying drawings.

[0021] Example 1:

[0022] This embodiment provides a multimode microwave power amplifier circuit structure with switchable ultra-wideband and communication frequency bands and continuously adjustable communication frequency, including a transistor, a matching inductor, a stabilizing resistor, a DC blocking capacitor, a matching microstrip line, an AC blocking resistor, a decoupling capacitor, a switching transistor, a mode switching capacitor, a mode switching inductor, a mode switching resistor, a capacitor in a continuously adjustable branch, an inductor, and a switching transistor. The input of a single transistor is matched using an inductor, a resistor, and a microstrip line, while the output is matched using only a microstrip line. After passing through the DC blocking capacitor, the amplifier is connected to a multi-stage traveling wave amplifier circuit via a microstrip line. Switching between ultra-wideband and multiple communication frequency bands can be achieved by changing the control voltage of the switching transistor that controls the mode switching capacitor, inductor, and resistor, the control voltage of the switching transistor in the continuously adjustable branch, and the drain power supply circuit of the preceding circuit.

[0023] like Figure 1It is a multi-mode microwave power amplifier circuit structure with switchable ultra-wideband and communication frequency band and continuously adjustable communication frequency. c =V0=V H =-40V, V dp =V Z =0V and the power supply circuit of the front-stage drain is a DC source V ds1,1 When the power supply branch is in operation, due to the DC source V ds1,1 Inductance L on the power supply branch D1,1 The value is 1500nH. At this time, the low-frequency signal cannot leak from the drain, and each continuously adjustable branch is turned off. Therefore, the power amplifier works in ultra-wideband mode. The RF signal is first amplified by the pre-amplifier circuit composed of transistor Q0 and its matching network. The pre-amplifier transistor Q0 is selected to have a smaller size for matching to obtain ultra-wideband flat amplification. The RF signal output by the pre-amplifier circuit passes through the DC blocking capacitor C B2 Then it enters the post-amplifier circuit. When the continuously adjustable branch is turned off, the post-amplifier circuit is a distributed amplifier topology with a low-pass structure. The microstrip line MLIN1 at the input end still participates in the output matching of transistor Q0. Transistors Q1, Q2, and Q3 are selected with different sizes to achieve the best power and efficiency matching. The drain matching inductor L of transistor Q1 d Select the inductor to match. DC blocking capacitor C B1 、C B3 Select a large external capacitor, C B2 Select large on-chip capacitors to isolate low frequencies from DC and AC inductors L D1 and L D2 Choose a large external inductor to prevent low-frequency signal leakage.

[0024] When the control voltage V c =0V, V dp = -40V and the drain power supply circuit of the previous stage is switched to the DC source V ds1,2 When the power supply branch is in operation, the continuously adjustable branch passband and band-stop network works, and the DC blocking capacitor C B1 、C B2 and the on-chip mode switching capacitor C BS1 、C BS2 The series connection forms a high-pass network, and the DC source V ds1,2 Inductance L on the power supply branch D1,2 The value is 3.3nH. At this time, the power amplifier works in the narrowband communication mode. By changing the Q of the switching transistor in the continuously adjustable branch scn The control voltage of (n=1,2,3,4) can change the equivalent capacitance value of a single reconfigurable capacitor, thereby changing the equivalent capacitance value of the reconfigurable capacitor group, realizing the movement of the center frequency of the bandpass network. The entire reconfigurable bandpass network and the band-stop capacitor C cThe parallel connection forms a reconfigurable bandpass and bandstop network, and then by changing the control voltage V0, V Z and V H Optimize narrowband performance. When the control voltage V c1 =V c2 =V c3 =V c4 =V0=V Z =V H = 0V, the power amplifier works in mode 1. When the control voltage V c1 =V c3 =0V, V c2 =V c4 =V0=V Z =V H =-40V, the power amplifier works in mode 2. When the control voltage V c2 =V0=0V, V c1 =V c3 =V c4 =-10V, V Z =V H =-40V, the power amplifier works in mode 3. When V0 = 0V, V c1 =V c2 =V c3 =V c4 =V Z =V H =-40V, the power amplifier works in mode 4.

[0025] The simulation power and efficiency of Example 1 in the ultra-wideband working mode and the multi-communication frequency band working mode are respectively as follows: Figure 3 、 4Simulations show that in ultra-wideband mode, the amplifier operates at frequencies from 0.03 to 6 GHz, with an output power greater than 40.2 dBm, a power-added efficiency greater than 39%, and a gain greater than 16 dB, as shown by the red curve. In communication-band mode, example mode 1 operates at frequencies from 2.3 to 2.5 GHz, with an output power greater than 41 dBm and a power-added efficiency greater than 47%, as shown by the blue curve. Example mode 2 operates at frequencies from 3.3 to 3.6 GHz, with an output power greater than 40.3 dBm and a power-added efficiency greater than 45%, as shown by the green curve. Example mode 3 operates at frequencies from 4.4 to 4.7 GHz, with an output power greater than 41.1 dBm and a power-added efficiency greater than 48%, as shown by the purple curve. Example mode 4 operates at frequencies from 5.1 to 5.4 GHz, with an output power greater than 41 dBm and a power-added efficiency greater than 51%, as shown by the orange curve. (The above communication-band operating frequencies are typical frequencies and do not represent all operating bands.) By changing the control mode of the switching transistors that switch the capacitors, inductors, and resistors and the control voltage of the switching transistors in the continuously adjustable branches, the center frequency of the communication band can theoretically move continuously within 2.4 to 5.4 GHz, realizing continuous adjustment of the narrowband frequency.

[0026] In summary, the present invention proposes a novel multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit for electronic warfare and multi-band communication systems. By adjusting the control voltage of the switching transistor and switching the drain power supply circuit of the front-stage circuit, the mode switching of ultra-wideband and multi-band communication can be achieved, realizing a multi-mode microwave power amplifier with switchable ultra-wideband and communication bands on the entire chip and continuously adjustable communication frequency.

Claims

1. A multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit, comprising a pre-amplifier circuit, a mode switching circuit, a post-amplifier circuit, and a continuously adjustable branch; The pre-stage amplifier circuit comprises: DC blocking capacitor C B1 , stabilizing resistor R in , isolation resistor RG1, inductor L0, mode switching capacitor C BS1 , control switching transistor Q s1 , gate supply inductor L G , transistor Q0, decoupling capacitor C de1 , the first continuously adjustable branch, output matching inductor L1, DC blocking capacitor C B2 , drain power supply circuit; the DC blocking capacitor C B1 One end is used as the input of the pre-amplifier circuit, and the other end is connected to the stabilizing resistor R in , mode switching capacitor C BS1 , input matching inductor L0, gate supply inductor L G , isolation resistor RG1, decoupling capacitor C de1 , decoupling capacitor C de1 The other end of the ground is connected to the decoupling capacitor C de1 The common point is connected to the DC power supply V gs1 , input matching inductor L0 and gate supply inductor L G The common point of the first continuously adjustable branch and the gate of the transistor Q0 are additionally connected, and the stabilizing resistor R in and mode switching capacitor C BS1 The common point of the control switch transistor Q s1 The source of the mode switching capacitor C BS1 The common point with the input matching inductor L0 is connected to the control switch transistor Q s1 The drain of the switching transistor Q s1 The gate is connected to the control voltage V dp The source of transistor Q0 is grounded, and the drain is connected to one end of the output matching inductor L1. The other end of the output matching inductor L1 is connected to the DC blocking capacitor C. B2 One end of the DC blocking capacitor C B2 The other end is used as the output of the pre-stage circuit; the output is matched with the inductor L1 and the DC blocking capacitor C B2 A drain power supply circuit is connected therebetween; A mode switching circuit is provided between the pre-stage amplifier circuit and the post-stage amplifier circuit; The post-amplifier circuit includes: a first matching microstrip line MLIN1, an inductor L g , the second matching microstrip line MLIN2, the third matching microstrip line MLIN3, three RC parallel networks, the drain matching inductor L d , fourth matching microstrip line MLIN4, fifth matching microstrip line MLIN5, sixth matching microstrip line MLIN6, isolation resistor R G2 , mode switching resistor R GS2 and the corresponding control switch transistor Q s4 , decoupling capacitor C de3 and C de4 , the first LC series resonant network, the switching transistor Q s5 , the second LC series resonant network, the DC blocking capacitor C B3 , isolation inductance L D2 , transistors Q1, Q2, Q3; one end of the first matching microstrip line MLIN1 is used as the input end of the post-amplifier circuit, and the other end is connected to the inductor L in sequence g , the second matching microstrip line MLIN2, the third matching microstrip line MLIN3, the isolation resistor R G2 , decoupling capacitor C de3 , decoupling capacitor C de3 The end of the first matching microstrip line MLIN1 and the inductor L g The middle of the second continuously adjustable branch and one end of the first RC parallel network are connected. The other end of the first RC parallel network is connected to the gate of the transistor Q1. The drain of the transistor Q1 is connected to the drain matching inductor L in turn. d , fourth matching microstrip line MLIN4, fifth matching microstrip line MLIN5, sixth matching microstrip line MLIN6, DC blocking capacitor C B3 , DC blocking capacitor C B3 The end of is the output end; the inductor L g The middle of the second matching microstrip line MLIN2 is connected to the third continuously adjustable branch and one end of the second RC parallel network. The other end of the second RC parallel network is connected to the gate of the transistor Q2. The drain of the transistor Q2 is connected to the matching inductor L. d The middle of the fourth matching microstrip line MLIN4; the middle of the second matching microstrip line MLIN2 and the third matching microstrip line MLIN3 is connected to the fourth continuously adjustable branch and one end of the third RC parallel network, the other end of the third RC parallel network is connected to the gate of the transistor Q3, and the drain of the transistor Q3 is connected to the middle of the fourth matching microstrip line MLIN4 and the fifth matching microstrip line MLIN5; the third matching microstrip line MLIN3 and the isolation resistor R G2 The middle is connected to the switching transistor Q s4 The source of the switching transistor Q s4 The gate of the switching transistor Q is connected to the control voltage V0. s4 The drain-connected mode switching resistor R GS2 One end of the mode switching resistor R GS2 The other end is connected to the isolation resistor R G2 With the decoupling capacitor C de3 The common node of the fifth matching microstrip line MLIN5 and the sixth matching microstrip line MLIN6 is connected to one end of the first LC series resonant network, and the other end of the first LC series resonant network is grounded; the sixth matching microstrip line MLIN6 is connected to the DC blocking capacitor C B3 The middle of the second LC series resonant network is connected to one end, and the other end of the second LC series resonant network is connected to the switching transistor Q s5 The source of the switching transistor Q s5 The gate is connected to the control voltage V H , switching transistor Q s5 The drain of the sixth matching microstrip line MLIN6 is grounded; the DC blocking capacitor C B3 The decoupling capacitor C is connected in the middle de4 One end and the isolation inductor L D2 One end of the decoupling capacitor C de4 The other end of the ground, the isolation inductor L D2 One end is connected to a DC power supply V ds2 . The first LC series resonant network and the second LC series resonant network have the same structure, which is a series structure of an inductor and a capacitor.

2. The multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit according to claim 1, characterized in that: The first continuously adjustable branch, the second continuously adjustable branch, the third continuously adjustable branch and the fourth continuously adjustable branch have the same structure and all include: a control switch transistor Q sc , capacitor C c 、Inductor L c , four reconfigurable capacitors C cn , four switching transistors Q scn , n=1,2,3,4; control switch transistor Q sc The source of the control switch transistor Q sc The gate is connected to the control voltage V c , controls the switching transistor Q sc The drain connection capacitance C c One end of the capacitor C c The other end is connected to the switching transistor Q scn The source and inductor L c One end of the switching transistor Q scn The gates of the cn , switching transistor Q scn The drains of the capacitors C are connected one by one. cn One end of the capacitor C forms a reconfigurable capacitor group consisting of four reconfigurable capacitors; cn The other end of the inductor L c The connection serves as the input end of the continuously adjustable branch.

3. The multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit according to claim 1, characterized in that: The drain power supply circuit is a two-way power supply connected in parallel, one of which is connected in turn to the inductor L D1,1 , decoupling capacitor C de2,1 To ground, inductor L D1,1 With the decoupling capacitor C de2,1 Connect a DC power supply V ds1,1 , the other one is connected to the inductor L D1 , decoupling capacitor C de2,2 To ground, inductor L D1,2 With the decoupling capacitor C c2,2 Connect a DC power supply V ds1,2 .

4. The multi-mode ultra-wideband continuously adjustable microwave power amplifier circuit according to claim 1, wherein: The mode switching circuit includes: a DC blocking capacitor C B2 , mode switching inductor L2 and corresponding control switch transistor Q s2 , mode switching capacitor C BS2 and the corresponding control switch transistor Q s3 ; The mode switching circuit starts from the input end and connects the DC blocking capacitor C B2 , mode switching inductor L2, mode switching capacitor C BS2 , DC blocking capacitor C B2 Connect the switching transistor Q between the mode switching inductor L2 s2 The source of the mode switching inductor L2 and the mode switching capacitor C BS2 Connected to the switching transistor Q s2 The drain of the switching transistor Q s3 The source of the switching transistor Q s2 The gate is connected to the control voltage V Z ;Switching transistor Q s3 The gate is connected to the control voltage V dp , mode switching capacitor C BS2 With the switching transistor Q s3 The drains are connected in common as the output end of the mode switching circuit.

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