Double-frequency millimeter wave power amplifier based on composite right / left hand transmission line

Abstract

The invention discloses a double-frequency millimeter wave power amplifier based on a composite right / left hand transmission line. The double-frequency millimeter wave power amplifier comprises an input matching circuit, a first-stage amplifying circuit, a first-second-stage matching circuit, a second-stage amplifying circuit, a second-third-stage matching circuit, a third-stage amplifying circuit and an output matching circuit. According to the invention, the input matching circuit utilizes the multi-resonance characteristic of a composite right / left hand transmission line structure, and adopts a dual-frequency matching scheme that a dual-frequency filter network designed based on an asymmetric composite right / left hand transmission line is combined with an input matching branch, so that simultaneous matching of fundamental waves is realized on two frequency points which are far away from each other; therefore, the dual-frequency millimeter wave power amplifier has the characteristic of dual-frequency simultaneous high-efficiency output. The circuit of the dual-frequency millimeter wave power amplifier avoids introduction of a switching circuit, is simple in structure and easy to realize, can realize stable dual-frequency high-efficiency characteristics without an additional control circuit, and has a wide application prospect in the field of wireless communication.

Description

Technical Field

[0001] The invention belongs to the field of microwave radio frequency communication, and in particular relates to a dual-frequency millimeter wave power amplifier based on a composite left-handed and right-handed transmission line. Background Art

[0002] With the continuous development of communication technology, spectrum resources in low-frequency bands are becoming increasingly scarce. With the continuous introduction of new communication standards, millimeter-wave bands are gradually being included in the scope of communication applications to improve communication capacity. As an important component in RF front-end communication, the performance of the power amplifier directly affects the quality of communication. Traditional broadband amplifiers are difficult to guarantee good power and efficiency characteristics while covering two operating frequency bands that are far apart at the same time, especially in the millimeter-wave band, where the parasitic effects and losses of components will be further deteriorated. In this context, high-performance millimeter-wave power amplifiers that can meet multiple frequency bands at the same time are of great significance.

[0003] Existing dual-band power amplifiers generally use switching circuits to achieve the reconstruction or switching of matching networks in different operating frequency bands, which increases the circuit area and faces problems such as high loss and complex design. Especially in the high-frequency millimeter wave band, the power loss and related parasitic effects will become more serious. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a dual-frequency millimeter wave power amplifier based on a composite left-handed and right-handed transmission line. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] The present invention provides a dual-frequency millimeter wave power amplifier based on a composite left-handed and right-handed transmission line, comprising:

[0006] An input matching circuit, a first-stage amplifying circuit, a first- and second-stage matching circuit, a second-stage amplifying circuit, a second- and third-stage matching circuit, a third-stage amplifying circuit, and an output matching circuit; wherein,

[0007] The input matching circuit is used to provide a first gate bias voltage to the first-stage amplifier circuit, match the characteristic impedance of the radio frequency system to the source impedance of the first-stage amplifier circuit, and transmit the input radio frequency signal to the first-stage amplifier circuit; the input matching circuit includes an input matching branch and a dual-frequency filtering network based on an asymmetric composite left-handed transmission line design;

[0008] The first-stage amplifier circuit is used to amplify the input radio frequency signal and output a first amplified signal;

[0009] The first-stage and second-stage matching circuit is used to provide a first drain bias voltage to the first-stage amplifier circuit, provide a second gate bias voltage to the second-stage amplifier circuit, match the conjugate of the load impedance of the first-stage amplifier circuit with the source impedance of the second-stage amplifier circuit, and transmit the first amplified signal to the second-stage amplifier circuit;

[0010] The second-stage amplifier circuit is used to amplify the first amplified signal and output a second amplified signal;

[0011] The second-stage and third-stage matching circuit is used to provide a second drain bias voltage to the second-stage amplifier circuit, provide a third gate bias voltage to the third-stage amplifier circuit, match the conjugate of the load impedance of the second-stage amplifier circuit with the source impedance of the third-stage amplifier circuit, and transmit the second amplified signal to the third-stage amplifier circuit;

[0012] The third-stage amplifier circuit is used to amplify the second amplified signal and output a third amplified signal;

[0013] The output matching circuit is used to provide a third drain bias voltage to the third-stage amplifier circuit, match the conjugate of the load impedance of the third-stage amplifier circuit to the characteristic impedance of the radio frequency system, and output the third amplified signal.

[0014] In one embodiment of the present invention, an input matching branch includes: an input matching sub-circuit and a first gate bias circuit.

[0015] In one embodiment of the present invention, the first gate bias circuit comprises:

[0016] Resistor R1, capacitor C1, microstrip line TL2;

[0017] The first end of the resistor R1 is connected to the bias voltage VG1, and the second end is connected to the first end of the microstrip line TL2;

[0018] The first end of the capacitor C1 is connected to the first end of the microstrip line TL2, and the second end is grounded;

[0019] The second end of the microstrip line TL2 serves as an output end of the first gate bias circuit.

[0020] In one embodiment of the present invention, the input matching sub-circuit comprises:

[0021] Capacitor C2, capacitor C3, microstrip line TL1 and microstrip line TL3;

[0022] The first end of the capacitor C2 is grounded, and the second end is connected to the first end of the microstrip line TL1;

[0023] The first end of the capacitor C3 serves as the input end of the input matching branch to receive the input RF signal, and the second end is connected to the first end of the microstrip line TL3;

[0024] The second end of the microstrip line TL1 is connected to the second end of the microstrip line TL2 as the output end of the input matching branch;

[0025] The second end of the microstrip line TL3 is connected to the first end of the microstrip line TL1 .

[0026] In one embodiment of the present invention, the dual-frequency filtering network comprises:

[0027] Capacitor C4, capacitor C5, capacitor C6, microstrip line TL4, microstrip line TL5 and microstrip line TL6; wherein,

[0028] The first end of the capacitor C4 is connected to the first end of the capacitor C6, and the second end is connected to the first end of the microstrip line TL4;

[0029] The first end of the capacitor C5 is connected to the first end of the microstrip line TL5, and the second end is connected to the first end of the capacitor C4;

[0030] The second end of the capacitor C6 is grounded;

[0031] The second end of the microstrip line TL4 is connected to the output end of the input matching branch as the output end of the input matching circuit;

[0032] A first end of the microstrip line TL6 is connected to a first end of the capacitor C6 , and a second end of the microstrip line TL6 is connected to a second end of the capacitor C6 .

[0033] In one embodiment of the present invention, each amplifier circuit comprises: a transistor and a grounded microstrip line; wherein,

[0034] The gate of the transistor serves as the input terminal of each level of the amplifier circuit, the source is connected to the first end of the ground microstrip line, and the drain serves as the output terminal of each level of the amplifier circuit;

[0035] A second end of the ground microstrip line is grounded.

[0036] In one embodiment of the present invention, the sizes of transistors in each stage of the amplifier circuit are determined according to the amplifier output conditions.

[0037] In one embodiment of the present invention, a first-level and second-level matching circuit includes:

[0038] Capacitor C7, capacitor C8, capacitor C9, capacitor C10, microstrip line TL7, microstrip line TL8, microstrip line TL9, microstrip line TL10 and resistor R2; wherein,

[0039] The first end of the capacitor C7 is connected to the bias voltage VD1, and the second end is grounded;

[0040] The first end of the capacitor C8 is connected to the second end of the microstrip line TL7, and the second end is connected to the first end of the microstrip line TL8;

[0041] The first end of the capacitor C9 is grounded, and the second end is connected to the second end of the microstrip line TL8;

[0042] The first end of the capacitor C10 is grounded, and the second end is connected to the second end of the resistor R2;

[0043] The first end of the microstrip line TL7 is connected to the first end of the capacitor C7, and the second end serves as the input end of the primary and secondary matching circuit;

[0044] The first end of the microstrip line TL9 is connected to the second end of the microstrip line TL8, and the second end is connected to the second end of the microstrip line TL10;

[0045] The first end of the microstrip line TL10 is connected to the second end of the resistor R2, and the second end serves as the output end of the primary and secondary matching circuit;

[0046] The first end of the resistor R2 is connected to the bias voltage VG2.

[0047] In one embodiment of the present invention, the second and third level matching circuit comprises:

[0048] Capacitor C11, capacitor C12, capacitor C13, capacitor C14, capacitor C15, microstrip line TL13, microstrip line TL14, microstrip line TL15, microstrip line TL17 and resistor R3; wherein,

[0049] The first end of the capacitor C11 is connected to the second end of the microstrip line TL15, and the second end is connected to the first end of the microstrip line TL13;

[0050] The first end of the capacitor C12 is grounded, and the second end is connected to the second end of the microstrip line TL13;

[0051] The first end of the capacitor C13 is grounded, and the second end is connected to the second end of the microstrip line TL14;

[0052] The first end of the capacitor C14 is connected to the bias voltage VD2, and the second end is grounded;

[0053] The first end of the capacitor C15 is connected to the second end of the resistor R3, and the second end is grounded;

[0054] The second end of the microstrip line TL13 is connected to the first end of the microstrip line TL14;

[0055] The second end of the microstrip line TL14 is connected to the second end of the microstrip line TL17;

[0056] The first end of the microstrip line TL15 is connected to the first end of the capacitor C14, and the second end serves as the input end of the second and third level matching circuit;

[0057] The first end of the microstrip line TL17 is connected to the second end of the resistor R3, and the second end serves as the output end of the second and third level matching circuit;

[0058] The first end of the resistor R3 is connected to the bias voltage VG3.

[0059] In one embodiment of the present invention, the output matching circuit comprises:

[0060] Capacitor C16, capacitor C17, capacitor C18, microstrip line TL18, microstrip line TL19 and microstrip line TL20; wherein,

[0061] The first end of the capacitor C16 is connected to the bias voltage VD3, and the second end is grounded;

[0062] The first end of the capacitor C17 is connected to the first end of the capacitor C18, and the second end is grounded;

[0063] The first end of the capacitor C18 is connected to the second end of the microstrip line TL19, and the second end serves as the output end of the output matching circuit;

[0064] The first end of the microstrip line TL18 serves as the input end of the output matching circuit, and the second end is connected to the first end of the microstrip line TL19;

[0065] A first end of the microstrip line TL20 is connected to a first end of the capacitor C16 , and a second end of the microstrip line TL19 is connected to a first end of the microstrip line TL19 .

[0066] Beneficial effects of the present invention:

[0067] In the scheme provided by the present invention, the multi-resonance characteristics of the composite left-handed transmission line structure are utilized through the input matching circuit, and a dual-frequency matching scheme combining a dual-frequency filtering network based on the asymmetric composite left-handed transmission line design and an input matching branch is adopted to achieve simultaneous fundamental wave matching at two far-apart frequency points, so that the dual-frequency millimeter-wave power amplifier has the characteristics of dual-frequency simultaneous high-efficiency output. The circuit of the dual-frequency millimeter-wave power amplifier avoids the introduction of a switching circuit, has a simple structure, is easy to implement, and can achieve stable dual-frequency high-efficiency characteristics without an additional control circuit, and has broad application prospects in the field of wireless communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic diagram of the principle of a dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided by an embodiment of the present invention;

[0069] Figure 2 A schematic diagram of the structure of an input matching circuit of a dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided by an embodiment of the present invention;

[0070] Figure 3 A simulation result diagram of the filtering effect of a filtering network based on a left-handed composite transmission line provided by an embodiment of the present invention;

[0071] Figure 4 A diagram showing simulation results of an input matching circuit of a dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided in an embodiment of the present invention;

[0072] Figure 5 A diagram showing the simulation results of small signal scattering parameters of a dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided in an embodiment of the present invention;

[0073] Figure 6 A diagram showing the simulation results of small signal scattering parameters in two frequency bands of a dual-band millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided in an embodiment of the present invention;

[0074] Figure 7 This is a diagram of large signal simulation results of a dual-band millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided in an embodiment of the present invention.

[0075] Reference numerals:

[0076] 1-input matching circuit, 2-first stage amplifier circuit, 3-first and second stage matching circuit, 4-second stage amplifier circuit, 5-second and third stage matching circuit, 6-third stage amplifier circuit, 7-output matching circuit, 11-input matching branch, 12-dual-frequency filter network. DETAILED DESCRIPTION

[0077] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0078] In order to solve the problem of complex design and high loss of the existing millimeter wave dual-band power amplifier, the embodiment of the present invention provides a dual-band millimeter wave power amplifier based on a composite left-handed transmission line, such as Figure 1 As shown, this may include:

[0079] An input matching circuit 1, a first-stage amplifier circuit 2, a first- and second-stage matching circuit 3, a second-stage amplifier circuit 4, a second- and third-stage matching circuit 5, a third-stage amplifier circuit 6, and an output matching circuit 7; wherein,

[0080] An input matching circuit 1 is used to provide a first gate bias voltage to the first-stage amplifier circuit 2, match the characteristic impedance of the radio frequency system to the source impedance of the first-stage amplifier circuit 2, and transmit the input radio frequency signal to the first-stage amplifier circuit 2; the input matching circuit 1 includes an input matching branch 11 and a dual-frequency filter network 12 based on an asymmetric composite left-handed transmission line design;

[0081] A first-stage amplifier circuit 2, used to amplify the input radio frequency signal and output a first amplified signal;

[0082] A first-stage and second-stage matching circuit 3, used to provide a first drain bias voltage to the first-stage amplifier circuit 2, provide a second gate bias voltage to the second-stage amplifier circuit 4, match the conjugate of the load impedance of the first-stage amplifier circuit 2 with the source impedance of the second-stage amplifier circuit 4, and transmit the first amplified signal to the second-stage amplifier circuit 4;

[0083] The second stage amplifier circuit 4 is used to amplify the first amplified signal and output a second amplified signal;

[0084] The second-stage and third-stage matching circuit 5 is used to provide a second drain bias voltage to the second-stage amplifier circuit, provide a third gate bias voltage to the third-stage amplifier circuit 6, match the conjugate of the load impedance of the second-stage amplifier circuit 4 with the source impedance of the third-stage amplifier circuit 6, and transmit the second amplified signal to the third-stage amplifier circuit 6;

[0085] A third-stage amplifier circuit 6, used for amplifying the second amplified signal and outputting a third amplified signal;

[0086] The output matching circuit 7 is used to provide a third drain bias voltage to the third-stage amplifier circuit 6, match the conjugate of the load impedance of the third-stage amplifier circuit 6 to the characteristic impedance of the radio frequency system, and output the third amplified signal.

[0087] The dual-frequency millimeter wave power amplifier based on the composite left-handed transmission line provided in the embodiment of the present invention utilizes the multi-resonance characteristics of the composite left-handed transmission line structure through the input matching circuit, and adopts a dual-frequency matching scheme combining a dual-frequency filter network designed based on an asymmetric composite left-handed transmission line and an input matching branch to achieve simultaneous fundamental wave matching at two far-apart frequency points, so that the dual-frequency millimeter wave power amplifier has the characteristics of dual-frequency simultaneous high-efficiency output. The circuit of the dual-frequency millimeter wave power amplifier avoids the introduction of a switching circuit, has a simple structure, is easy to implement, and can achieve stable dual-frequency high-efficiency characteristics without an additional control circuit, and has broad application prospects in the field of wireless communications.

[0088] For ease of understanding, each module of the dual-band millimeter-wave power amplifier provided in an embodiment of the present invention is introduced separately below.

[0089] Input matching circuit

[0090] Input matching circuit 1 Figure 2 As shown, this may include:

[0091] An input matching branch 11 and a dual-frequency filtering network 12 designed based on an asymmetric composite left-handed transmission line.

[0092] Specifically, from Figure 2 It can be seen from the figure that the input matching branch 11 may include: an input matching sub-circuit and a first gate bias circuit.

[0093] The first gate bias circuit may include:

[0094] Resistor R1, capacitor C1, microstrip line TL2;

[0095] The first end of the resistor R1 is connected to the bias voltage VG1, and the second end is connected to the first end of the microstrip line TL2;

[0096] A first end of the capacitor C1 is connected to a first end of the microstrip line TL2, and a second end is grounded;

[0097] The second end of the microstrip line TL2 serves as an output end of the first gate bias circuit.

[0098] The first gate bias circuit can be used to provide a first gate bias voltage to the transistor M1 in the first-stage amplifying circuit 2 .

[0099] Input matching subcircuit, which may include:

[0100] Capacitor C2, capacitor C3, microstrip line TL1 and microstrip line TL3;

[0101] A first end of the capacitor C2 is grounded, and a second end is connected to a first end of the microstrip line TL1;

[0102] The first end of the capacitor C3 serves as the input end of the input matching branch 11 to receive the input RF signal, and the second end is connected to the first end of the microstrip line TL3;

[0103] The second end of the microstrip line TL1 is connected to the second end of the microstrip line TL2 as the output end of the input matching branch 11;

[0104] The second end of the microstrip line TL3 is connected to the first end of the microstrip line TL1 .

[0105] It can be understood that the input end of the input matching sub-circuit serves as the input end of the input matching branch 11 to receive the input radio frequency signal.

[0106] The dual-frequency filtering network 12 may include:

[0107] Capacitor C4, capacitor C5, capacitor C6, microstrip line TL4, microstrip line TL5 and microstrip line TL6; wherein,

[0108] A first end of the capacitor C4 is connected to a first end of the capacitor C6, and a second end is connected to a first end of the microstrip line TL4;

[0109] A first end of the capacitor C5 is connected to a first end of the microstrip line TL5, and a second end is connected to a first end of the capacitor C4;

[0110] The second end of the capacitor C6 is grounded;

[0111] The second end of the microstrip line TL4 is connected to the output end of the input matching branch 11, serving as the output end of the input matching circuit 1;

[0112] A first end of the microstrip line TL6 is connected to a first end of the capacitor C6 , and a second end of the microstrip line TL6 is connected to a second end of the capacitor C6 .

[0113] The dual-frequency filter network 12 inserts filter zeros between the traditional matching networks in parallel to reduce the insertion loss of the matching network. At the same time, in order to overcome the shortcomings of the inductor elements in the traditional composite left-handed unit structure in the millimeter wave frequency band, which are serious parasitic effects and difficult to layout, the inductors in the traditional composite left-handed units are replaced by microstrip lines, which effectively reduces the insertion loss introduced by the dual-frequency input matching network and achieves a good filter passband. On the other hand, in order to flexibly adjust the filter zeros in the frequency band, the dual-frequency filter network based on the composite left-handed transmission line is set to an asymmetric structure, that is, the values ​​of the left-handed unit and the right-handed unit are different, thereby overcoming the problem of the difficulty in adjusting the filter zeros in the frequency band. For the simulation result diagram of the filtering effect of the filter network based on the left-handed composite transmission line, please refer to Figure 3 ,from Figure 3 It can be seen that between the center frequencies of 28 GHz and 38 GHz, the filtering band notch effect is effectively introduced, and at the same time, a good dual-frequency matching effect can be achieved. Figure 4 ,from Figure 4 It can be seen that good matching can be achieved at the center frequency of 28GHz / 38GHz, and the power transmission of the intermediate spurious frequency points can be effectively suppressed.

[0114] The input matching circuit matches the characteristic impedance of the RF system to the source impedance of the first-stage amplifier circuit 2, thereby minimizing the loss of signal transmission. The RF system (RF system) refers to a system that uses RF signals for communication, signal processing, or energy transmission. In the RF system, impedance is a critical parameter in the signal transmission link. The characteristic impedance of the RF system usually refers to the input or output impedance of RF components such as transmission lines, antennas, and amplifiers. The characteristic impedance of the RF system can be 50 ohms or 75 ohms.

[0115] It can be understood that the input matching circuit 1 provided in the embodiment of the present invention utilizes the multi-resonance characteristics of the composite left-handed transmission line structure, and adopts a dual-frequency matching scheme combining a dual-frequency filtering network designed based on an asymmetric composite left-handed transmission line and an input matching branch to achieve simultaneous fundamental wave matching at two far-apart frequency points, so that the dual-frequency millimeter-wave power amplifier has the characteristics of dual-frequency simultaneous high-efficiency output. While matching the dual frequencies, a filtering zero point is introduced into the frequency band by connecting the dual-frequency filtering network designed in parallel with an asymmetric composite left-handed transmission line, so that a good matching effect can be achieved at low loss at the two center frequencies, and a band notch effect is introduced between the two center frequencies to suppress the transmission of intermediate stray signals, filter out stray signals, and achieve dual-band matching output.

[0116] Amplifier circuits at all levels

[0117] Each level of amplifier circuit performs corresponding amplification processing on the signal it receives.

[0118] Each level of amplifier circuit may include: a transistor and a grounded microstrip line; wherein,

[0119] The gate of the transistor serves as the input terminal of each level of the amplifier circuit, the source is connected to the first end of the grounded microstrip line, and the drain serves as the output terminal of each level of the amplifier circuit;

[0120] A second end of the ground microstrip line is grounded.

[0121] Specifically, from Figure 1 It can be seen that for the first-stage amplifier circuit 2, it can include a transistor M1 and a ground microstrip line TL11; for the second-stage amplifier circuit 4, it can include a transistor M2 and a ground microstrip line TL12; for the third-stage amplifier circuit 6, it can include a transistor M3 and a ground microstrip line TL16.

[0122] It can be understood that for transistors in each level of amplifier circuit, the gate is the control terminal of the transistor. By providing a bias voltage to the gate, the electric field strength inside the transistor can be controlled, thereby adjusting the switching state or amplification capacity of the transistor. The essence of the bias voltage is to keep the passive device in a normal working state and realize the control of the input and output characteristics. In the amplifier circuit, the appropriate gate bias voltage can make the transistor or other nonlinear components always present electrical characteristics similar to DC operation when the input signal changes, so as to meet the correct transmission and amplification of the information signal. In addition, the gate bias voltage can also remove noise in the circuit, improve the reliability of the system, accelerate the turn-on and turn-off of the transistor, reduce the turn-on and turn-off losses, reduce DI / DT, protect the transistor and suppress EMI interference. The drain is the port where the current flows out of the transistor. By providing a bias voltage to the drain, the amplification capacity and output characteristics of the transistor can be adjusted. In the amplifier circuit, the appropriate drain bias voltage can optimize the amplification effect of the transistor and ensure that the transistor can work stably when amplifying tasks such as audio signals. In addition, the drain bias voltage also helps to protect the power grid and prevent the power grid from being broken down under abnormally high voltage conditions. The embodiment of the present invention provides appropriate bias voltages to the gate and drain of transistors in each level of amplifier circuits, which can not only ensure the normal operation of the transistors, but also optimize circuit performance and improve system reliability and stability.

[0123] Specifically, the size of the transistors in each level of the amplifier circuit is determined according to the amplifier output conditions, which may include:

[0124] The size selection of transistors M1, M2 and M3 can first determine the appropriate size of the output stage transistor M3 according to the requirements, wherein the size selection of transistor M3 can be reasonably balanced according to the difficulty of saturated output and dual-frequency matching to ensure the feasibility of dual-frequency output matching. The size selection of transistors M1 and M2 can be determined according to the power drive ratio to ensure that the power stage can be driven to saturation to achieve maximum power and efficiency, while avoiding the driver stage from entering the back-off region too early to reduce the overall linearity.

[0125] The dual-band millimeter-wave power amplifier provided in the embodiment of the present invention may be designed based on a 100nmGaN process, wherein the sizes of the transistor M1, the transistor M2, and the transistor M3 may be 4×25μm, 4×50μm, and 6×50μm, respectively.

[0126] Matching circuit between primary and secondary

[0127] The primary and secondary matching circuit 3 may include:

[0128] Capacitor C7, capacitor C8, capacitor C9, capacitor C10, microstrip line TL7, microstrip line TL8, microstrip line TL9, microstrip line TL10 and resistor R2; wherein,

[0129] A first end of the capacitor C7 is connected to the bias voltage VD1, and a second end is grounded;

[0130] A first end of the capacitor C8 is connected to the second end of the microstrip line TL7, and a second end of the capacitor C8 is connected to the first end of the microstrip line TL8;

[0131] A first end of the capacitor C9 is grounded, and a second end is connected to a second end of the microstrip line TL8;

[0132] A first end of the capacitor C10 is grounded, and a second end is connected to a second end of the resistor R2;

[0133] The first end of the microstrip line TL7 is connected to the first end of the capacitor C7, and the second end serves as the input end of the primary and secondary matching circuit 3;

[0134] A first end of the microstrip line TL9 is connected to a second end of the microstrip line TL8, and a second end is connected to a second end of the microstrip line TL10;

[0135] The first end of the microstrip line TL10 is connected to the second end of the resistor R2, and the second end serves as the output end of the primary and secondary matching circuit 3;

[0136] The first end of the resistor R2 is connected to the bias voltage VG2.

[0137] The first-stage and second-stage matching circuit 3 provides a first drain bias voltage to the first-stage amplifier circuit 2 and a second gate bias voltage to the second-stage amplifier circuit 4, matches the conjugate of the load impedance of the first-stage amplifier circuit 2 with the source impedance of the second-stage amplifier circuit 4, and transmits the first amplified signal to the second-stage amplifier circuit 4.

[0138] Specifically, from Figure 1 It can be seen that in the first-stage and second-stage matching circuit 3, capacitor C7 and microstrip line TL7 can constitute a first drain bias circuit, and the first drain bias circuit provides a first drain bias voltage to the first-stage amplifier circuit 2; capacitor C10, microstrip line TL10 and resistor R2 can constitute a second gate bias circuit, and the second gate bias circuit provides a second gate bias voltage to the second-stage amplifier circuit 4; capacitor C8, capacitor C9, microstrip line TL8 and microstrip line TL9 can constitute a first inter-stage matching sub-circuit, and the first inter-stage matching sub-circuit matches the conjugate of the load impedance of the first-stage amplifier circuit 2 with the source impedance of the second-stage amplifier circuit 4, so that the first-stage and second-stage matching circuit 3 transmits the first amplified signal to the second-stage amplifier circuit 4.

[0139] Matching circuit between the second and third stages

[0140] The second and third level matching circuit 5 may include:

[0141] Capacitor C11, capacitor C12, capacitor C13, capacitor C14, capacitor C15, microstrip line TL13, microstrip line TL14, microstrip line TL15, microstrip line TL17 and resistor R3; wherein,

[0142] A first end of the capacitor C11 is connected to a second end of the microstrip line TL15, and a second end of the capacitor C11 is connected to a first end of the microstrip line TL13;

[0143] A first end of the capacitor C12 is grounded, and a second end is connected to a second end of the microstrip line TL13;

[0144] A first end of the capacitor C13 is grounded, and a second end is connected to a second end of the microstrip line TL14;

[0145] A first end of the capacitor C14 is connected to the bias voltage VD2, and a second end is grounded;

[0146] A first end of the capacitor C15 is connected to a second end of the resistor R3, and a second end of the capacitor C15 is grounded;

[0147] The second end of the microstrip line TL13 is connected to the first end of the microstrip line TL14;

[0148] The second end of the microstrip line TL14 is connected to the second end of the microstrip line TL17;

[0149] The first end of the microstrip line TL15 is connected to the first end of the capacitor C14, and the second end serves as the input end of the second and third level matching circuit 5;

[0150] The first end of the microstrip line TL17 is connected to the second end of the resistor R3, and the second end serves as the output end of the second and third level matching circuit 5;

[0151] The first end of the resistor R3 is connected to the bias voltage VG3.

[0152] The second-stage and third-stage matching circuit 5 provides a second drain bias voltage to the second-stage amplifier circuit and a third gate bias voltage to the third-stage amplifier circuit, matches the conjugate of the load impedance of the second-stage amplifier circuit 4 with the source impedance of the third-stage amplifier circuit 6, and transmits the second amplified signal to the third-stage amplifier circuit 6.

[0153] Specifically, from Figure 1It can be seen that in the second-stage and third-stage matching circuit 5, the capacitor C14 and the microstrip line TL15 can constitute a second drain bias circuit, and the second drain bias circuit provides a second drain bias voltage to the second-stage amplifier circuit; the capacitor C15, the microstrip line TL17 and the resistor R3 can constitute a third gate bias circuit, and the third gate bias circuit provides a third gate bias voltage to the third-stage amplifier circuit 6; the capacitor C11, the capacitor C12, the capacitor C13, the microstrip line TL13 and the microstrip line TL14 can constitute a second inter-stage matching sub-circuit, and the second inter-stage matching sub-circuit matches the conjugate of the load impedance of the second-stage amplifier circuit 4 with the source impedance of the third-stage amplifier circuit 6, so that the second-stage and third-stage matching circuit 5 transmits the second amplified signal to the third-stage amplifier circuit 6.

[0154] Output matching circuit

[0155] The output matching circuit 7 may include:

[0156] Capacitor C16, capacitor C17, capacitor C18, microstrip line TL18, microstrip line TL19 and microstrip line TL20; wherein,

[0157] A first end of the capacitor C16 is connected to the bias voltage VD3, and a second end is grounded;

[0158] A first end of the capacitor C17 is connected to a first end of the capacitor C18, and a second end is grounded;

[0159] A first end of the capacitor C18 is connected to a second end of the microstrip line TL19, and the second end serves as an output end of the output matching circuit 7;

[0160] The first end of the microstrip line TL18 serves as the input end of the output matching circuit 7, and the second end is connected to the first end of the microstrip line TL19;

[0161] A first end of the microstrip line TL20 is connected to a first end of the capacitor C16 , and a second end of the microstrip line TL19 is connected to a first end of the microstrip line TL19 .

[0162] The output matching circuit 7 provides a third drain bias voltage to the third-stage amplifier circuit, matches the conjugate of the load impedance of the third-stage amplifier circuit 6 to the characteristic impedance of the radio frequency system, and outputs the third amplified signal. In order to simplify the structure of the output matching circuit 7 and reduce the loss of the power output stage to improve the saturated output power and efficiency of the dual-band power amplifier, the principle of component reuse is followed during the design process. The microstrip line TL20 and the capacitor C16 are used to provide a third drain bias voltage to the third-stage amplifier circuit to isolate the radio frequency signal, and are also used to match the conjugate of the load impedance of the third-stage amplifier circuit 6 to the characteristic impedance of the radio frequency system, thereby realizing component reuse and reducing the layout area.

[0163] In order to facilitate demonstration of the beneficial effects of the dual-band millimeter-wave power amplifier provided by the embodiment of the present invention, simulations of large signals and small signals are performed below respectively.

[0164] The simulation results of the small signal scattering parameters of the dual-band millimeter-wave power amplifier provided in the embodiment of the present invention are shown in FIG. Figure 5 The simulation results of small signal scattering parameters of dual-band millimeter-wave power amplifier in two frequency bands can be found in Figure 6 ;from Figure 5 and Figure 6 It can be seen that the dual-band millimeter-wave power amplifier can achieve simultaneous matching at the center frequencies of 28GHz and 38GHz, and the small signal gain can be 24dB and 21.8dB. In the low frequency band of 27-29GHz, the input reflection coefficient can be below -15dB, and the small signal gain is greater than 23.7dB; in the high frequency band of 37-39GHz, the input reflection coefficient can be below -15dB, and the small signal gain is greater than 21dB.

[0165] See the large signal simulation result diagram of the dual-band millimeter wave power amplifier provided in the embodiment of the present invention. Figure 7 .from Figure 7 It can be seen that the saturated output power of the dual-band millimeter-wave power amplifier is greater than 31dBm at the center frequencies of 28GHz and 38GHz, and the power added efficiency is greater than 37% and 34% respectively, which shows good dual-band output characteristics.

[0166] The embodiment of the present invention utilizes the multi-resonance characteristics of the composite left-handed transmission line structure through an input matching circuit, and adopts a dual-frequency matching scheme combining a dual-frequency filtering network designed based on an asymmetric composite left-handed transmission line and an input matching branch to achieve simultaneous fundamental wave matching at two far-apart frequency points, so that the dual-frequency millimeter-wave power amplifier has the characteristics of dual-frequency simultaneous high-efficiency output. The circuit of the dual-frequency millimeter-wave power amplifier avoids the introduction of a switching circuit, has a simple structure, is easy to implement, and can achieve stable dual-frequency high-efficiency characteristics without an additional control circuit. Combining dual-frequency matching technology with circuit element multiplexing technology, a design scheme for a dual-frequency millimeter-wave power amplifier with a simple structure and low loss is provided. The dual-frequency millimeter-wave power amplifier has a compact structure, is easy to implement, has the advantages of dual-band simultaneous output and high efficiency, and has broad application prospects in the field of modern wireless communications.

[0167] It should be noted that in the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0168] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line, characterized in that: include: An input matching circuit (1), a first-stage amplifying circuit (2), a first-stage and second-stage matching circuit (3), a second-stage amplifying circuit (4), a second-stage and third-stage matching circuit (5), a third-stage amplifying circuit (6), and an output matching circuit (7); wherein: The input matching circuit (1) is used to provide a first gate bias voltage to the first-stage amplifier circuit (2), match the characteristic impedance of the radio frequency system to the source impedance of the first-stage amplifier circuit (2), and transmit the input radio frequency signal to the first-stage amplifier circuit (2); the input matching circuit (1) comprises an input matching branch (11) and a dual-frequency filter network (12) designed based on an asymmetric composite left-handed transmission line; The first-stage amplifier circuit (2) is used to amplify the input radio frequency signal and output a first amplified signal; The first-stage and second-stage matching circuit (3) is used to provide a first drain bias voltage to the first-stage amplifier circuit (2), provide a second gate bias voltage to the second-stage amplifier circuit (4), match the conjugate of the load impedance of the first-stage amplifier circuit (2) with the source impedance of the second-stage amplifier circuit (4), and transmit the first amplified signal to the second-stage amplifier circuit (4); The second-stage amplifier circuit (4) is used to amplify the first amplified signal and output a second amplified signal; The second-stage and third-stage matching circuit (5) is used to provide a second drain bias voltage to the second-stage amplifier circuit, provide a third gate bias voltage to the third-stage amplifier circuit (6), match the conjugate of the load impedance of the second-stage amplifier circuit (4) with the source impedance of the third-stage amplifier circuit (6), and transmit the second amplified signal to the third-stage amplifier circuit (6); The third-stage amplifier circuit (6) is used to amplify the second amplified signal and output a third amplified signal; The output matching circuit (7) is used to provide a third drain bias voltage to the third-stage amplifier circuit (6), match the conjugate of the load impedance of the third-stage amplifier circuit (6) to the characteristic impedance of the radio frequency system, and output a third amplified signal.

2. The dual-frequency millimeter-wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: The input matching branch (11) comprises: an input matching subcircuit and a first gate bias circuit.

3. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 2, characterized in that: The first gate bias circuit comprises: Resistor R1, capacitor C1, microstrip line TL2; The first end of the resistor R1 is connected to the bias voltage VG1, and the second end is connected to the first end of the microstrip line TL2; The first end of the capacitor C1 is connected to the first end of the microstrip line TL2, and the second end is grounded; The second end of the microstrip line TL2 serves as an output end of the first gate bias circuit.

4. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 3, characterized in that: The input matching sub-circuit comprises: Capacitor C2, capacitor C3, microstrip line TL1 and microstrip line TL3; The first end of the capacitor C2 is grounded, and the second end is connected to the first end of the microstrip line TL1; The first end of the capacitor C3 serves as the input end of the input matching branch (11) to receive an input radio frequency signal, and the second end is connected to the first end of the microstrip line TL3; The second end of the microstrip line TL1 is connected to the second end of the microstrip line TL2 to serve as the output end of the input matching branch (11); The second end of the microstrip line TL3 is connected to the first end of the microstrip line TL1 .

5. The dual-frequency millimeter-wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: The dual-frequency filtering network (12) comprises: Capacitor C4, capacitor C5, capacitor C6, microstrip line TL4, microstrip line TL5 and microstrip line TL6; wherein, The first end of the capacitor C4 is connected to the first end of the capacitor C6, and the second end is connected to the first end of the microstrip line TL4; The first end of the capacitor C5 is connected to the first end of the microstrip line TL5, and the second end is connected to the first end of the capacitor C4; The second end of the capacitor C6 is grounded; The second end of the microstrip line TL4 is connected to the output end of the input matching branch (11) to serve as the output end of the input matching circuit (1); A first end of the microstrip line TL6 is connected to a first end of the capacitor C6 , and a second end of the microstrip line TL6 is connected to a second end of the capacitor C6 .

6. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: Each level of amplifier circuit includes: a transistor and a grounded microstrip line; wherein, The gate of the transistor serves as the input terminal of each level of the amplifier circuit, the source is connected to the first end of the ground microstrip line, and the drain serves as the output terminal of each level of the amplifier circuit; A second end of the ground microstrip line is grounded.

7. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 6, characterized in that: The size of the transistors in each stage of the amplifier circuit is determined according to the amplifier output conditions.

8. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: The primary and secondary matching circuit (3) comprises: Capacitor C7, capacitor C8, capacitor C9, capacitor C10, microstrip line TL7, microstrip line TL8, microstrip line TL9, microstrip line TL10 and resistor R2; wherein, The first end of the capacitor C7 is connected to the bias voltage VD1, and the second end is grounded; The first end of the capacitor C8 is connected to the second end of the microstrip line TL7, and the second end is connected to the first end of the microstrip line TL8; The first end of the capacitor C9 is grounded, and the second end is connected to the second end of the microstrip line TL8; The first end of the capacitor C10 is grounded, and the second end is connected to the second end of the resistor R2; The first end of the microstrip line TL7 is connected to the first end of the capacitor C7, and the second end serves as the input end of the primary and secondary matching circuit (3); The first end of the microstrip line TL9 is connected to the second end of the microstrip line TL8, and the second end is connected to the second end of the microstrip line TL10; The first end of the microstrip line TL10 is connected to the second end of the resistor R2, and the second end serves as the output end of the primary and secondary matching circuit (3); The first end of the resistor R2 is connected to the bias voltage VG2.

9. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: The second and third level matching circuit (5) comprises: Capacitor C11, capacitor C12, capacitor C13, capacitor C14, capacitor C15, microstrip line TL13, microstrip line TL14, microstrip line TL15, microstrip line TL17 and resistor R3; wherein, The first end of the capacitor C11 is connected to the second end of the microstrip line TL15, and the second end is connected to the first end of the microstrip line TL13; The first end of the capacitor C12 is grounded, and the second end is connected to the second end of the microstrip line TL13; The first end of the capacitor C13 is grounded, and the second end is connected to the second end of the microstrip line TL14; The first end of the capacitor C14 is connected to the bias voltage VD2, and the second end is grounded; The first end of the capacitor C15 is connected to the second end of the resistor R3, and the second end is grounded; The second end of the microstrip line TL13 is connected to the first end of the microstrip line TL14; The second end of the microstrip line TL14 is connected to the second end of the microstrip line TL17; The first end of the microstrip line TL15 is connected to the first end of the capacitor C14, and the second end serves as the input end of the second and third level matching circuit (5); The first end of the microstrip line TL17 is connected to the second end of the resistor R3, and the second end serves as the output end of the second- and third-stage matching circuit (5); The first end of the resistor R3 is connected to the bias voltage VG3.

10. The dual-frequency millimeter wave power amplifier based on composite left-handed and right-handed transmission lines according to claim 1, characterized in that: The output matching circuit (7) comprises: Capacitor C16, capacitor C17, capacitor C18, microstrip line TL18, microstrip line TL19 and microstrip line TL20; wherein, The first end of the capacitor C16 is connected to the bias voltage VD3, and the second end is grounded; The first end of the capacitor C17 is connected to the first end of the capacitor C18, and the second end is grounded; The first end of the capacitor C18 is connected to the second end of the microstrip line TL19, and the second end serves as the output end of the output matching circuit (7); The first end of the microstrip line TL18 serves as the input end of the output matching circuit (7), and the second end is connected to the first end of the microstrip line TL19; A first end of the microstrip line TL20 is connected to a first end of the capacitor C16 , and a second end of the microstrip line TL19 is connected to a first end of the microstrip line TL19 .

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