A dual-frequency millimeter-wave power amplifier based on composite left- and right-handed transmission lines

Abstract

This invention discloses a dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line, comprising: an input matching circuit, a first-stage amplifier circuit, a first-stage and second-stage matching circuit, a second-stage amplifier circuit, a second-stage and third-stage matching circuit, a third-stage amplifier circuit, and an output matching circuit. This invention utilizes the multi-resonance characteristics of the composite left-handed and right-handed transmission line structure in the input matching circuit. It employs a dual-frequency matching scheme combining a dual-frequency filter network designed based on an asymmetric composite left-handed and right-handed transmission line with the input matching branch. This achieves simultaneous fundamental frequency matching at two relatively far-distance frequency points, enabling the dual-frequency millimeter-wave power amplifier to possess the characteristic of simultaneous high-efficiency output at both frequencies. The circuit of this dual-frequency millimeter-wave power amplifier avoids the introduction of switching circuits, has a simple structure, is easy to implement, and can achieve stable dual-frequency high-efficiency characteristics without additional control circuitry, showing broad application prospects in the field of wireless communication.

Description

Technical Field

[0001] This invention belongs to the field of microwave radio frequency communication, specifically relating to a dual-frequency millimeter-wave power amplifier based on composite left and right hand transmission lines. Background Technology

[0002] With the continuous development of communication technology, low-frequency spectrum resources are becoming increasingly scarce. As new communication standards are constantly being introduced, millimeter-wave bands are gradually being incorporated into communication applications to improve communication capacity. Power amplifiers, as a crucial component in radio frequency (RF) front-end communication, directly impact communication quality. Traditional broadband amplifiers struggle to maintain good power and efficiency characteristics while simultaneously covering two widely separated operating frequency bands, especially in the millimeter-wave band where parasitic effects and losses are further exacerbated. Against this backdrop, high-performance millimeter-wave power amplifiers capable of simultaneously meeting the requirements of multiple frequency bands are of paramount importance.

[0003] Existing dual-band power amplifiers typically employ switching circuits to reconstruct or switch the matching network for different operating frequency bands. This increases circuit area and also presents problems such as high losses and complex design. Especially in the high-frequency millimeter-wave band, the power losses and related parasitic effects become even more severe. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line. The technical problem to be solved by this invention is achieved through the following technical solution:

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

[0006] The circuit includes an input matching circuit, a first-stage amplifier circuit, a first-stage / second-stage matching circuit, a second-stage amplifier circuit, a second-stage / third-stage matching circuit, a third-stage amplifier circuit, and an output matching circuit; among which,

[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 RF system to the source impedance of the first stage amplifier circuit, and transmit the input RF signal to the first stage amplifier circuit; the input matching circuit includes an input matching branch and a dual-frequency filter network based on an asymmetric composite left- and right-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, 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 interstage matching circuit is used to provide a second drain bias voltage to the second stage amplifier circuit, 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 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, the 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 includes:

[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 terminal of capacitor C1 is connected to the first terminal of microstrip line TL2, and the second terminal is grounded.

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

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

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

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

[0023] The first terminal of capacitor C3 serves as the input terminal of the input matching branch, receiving the input radio frequency signal, and the second terminal is connected to the first terminal of microstrip line TL3.

[0024] The second end of the microstrip line TL1 is connected to the second end of the microstrip line TL2, serving 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 includes:

[0027] Capacitors C4, C5, and C6; microstrip line TL4, TL5, and TL6; among them,

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

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

[0030] The second terminal of capacitor C6 is grounded;

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

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

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

[0034] The gate of the transistor serves as the input terminal of each stage 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 stage of the amplifier circuit.

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

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

[0037] In one embodiment of the present invention, the inter-level matching circuit includes:

[0038] Capacitors C7, C8, C9, and C10; microstrip line TL7, TL8, TL9, and TL10; and resistor R2; among which,

[0039] The first terminal of the capacitor C7 is connected to the bias voltage VD1, and the second terminal 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 terminal of the capacitor C9 is grounded, and the second terminal is connected to the second terminal of the microstrip line TL8.

[0042] The first terminal of the capacitor C10 is grounded, and the second terminal is connected to the second terminal 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 inter-stage 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 first-second inter-stage matching circuit.

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

[0047] In one embodiment of the present invention, the inter-stage matching circuit includes:

[0048] Capacitors C11, C12, C13, C14, and C15; microstrip line TL13, TL14, TL15, and TL17; and resistor R3; among which,

[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 terminal of the capacitor C12 is grounded, and the second terminal is connected to the second terminal of the microstrip line TL13.

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

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

[0053] The first terminal of capacitor C15 is connected to the second terminal of resistor R3, and the second terminal 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 inter-stage 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 inter-stage matching circuit.

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

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

[0060] Capacitors C16, C17, and C18; microstrip line TL18, TL19, and TL20; among them,

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

[0062] The first terminal of capacitor C17 is connected to the first terminal of capacitor C18, and the second terminal 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] The first end of the microstrip line TL20 is connected to the first end of the capacitor C16, and the second end is connected to the first end of the microstrip line TL19.

[0066] The beneficial effects of this invention are:

[0067] The solution provided by this invention utilizes the multi-resonance characteristics of a composite left-handed and right-handed transmission line structure through an input matching circuit. It employs a dual-frequency matching scheme combining a dual-frequency filter network based on an asymmetric composite left-handed and right-handed transmission line design with an input matching branch. This achieves simultaneous fundamental frequency matching at two relatively far-distance frequency points, enabling the dual-frequency millimeter-wave power amplifier to exhibit simultaneous high-efficiency output at both frequencies. This dual-frequency millimeter-wave power amplifier circuit avoids the introduction of switching circuits, resulting in a simple and easy-to-implement structure. It achieves stable dual-frequency high-efficiency characteristics without the need for additional control circuitry, and has broad application prospects in the field of wireless communication. Attached Figure Description

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

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

[0070] Figure 3 The figure shows the simulation results of the filtering effect of the filtering network based on the left-handed composite transmission line provided in the embodiment of the present invention.

[0071] Figure 4 The simulation results of the input matching circuit of a dual-frequency millimeter-wave power amplifier based on a composite left- and right-hand transmission line provided in an embodiment of the present invention are shown in the figure.

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

[0073] Figure 6 The following is a simulation result diagram of small signal scattering parameters in two frequency bands for a dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line provided in an embodiment of the present invention.

[0074] Figure 7 The figure shows the large-signal simulation results of a dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line, as provided in an embodiment of the present invention.

[0075] Figure label:

[0076] 1-Input matching circuit, 2-First stage amplifier circuit, 3-Matching circuit between first and second stages, 4-Second stage amplifier circuit, 5-Matching circuit between second and third stages, 6-Third stage amplifier circuit, 7-Output matching circuit, 11-Input matching branch, 12-Dual-frequency filter network. Detailed Implementation

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

[0078] To address the challenges of complex design and high loss in existing millimeter-wave dual-frequency power amplifiers, this invention provides a dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line, such as... Figure 1 As shown, it may include:

[0079] The circuit comprises: input matching circuit 1, first-stage amplifier circuit 2, first-stage / second-stage matching circuit 3, second-stage amplifier circuit 4, second-stage / third-stage matching circuit 5, third-stage amplifier circuit 6, and output matching circuit 7; wherein,

[0080] 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 RF system to the source impedance of the first stage amplifier circuit 2, and transmit the input RF signal to the first stage amplifier circuit 2; input matching circuit 1 includes input matching branch 11 and dual-frequency filter network 12 based on asymmetric composite left and right hand transmission line design;

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

[0082] 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 and a second gate bias voltage to the second-stage amplifier circuit 4, to 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 to 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 the second amplified signal;

[0084] The interstage matching circuit 5 is used to provide a second drain bias voltage to the second stage amplifier circuit and a third gate bias voltage to the third stage amplifier circuit 6. It 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.

[0085] The third-stage amplifier circuit 6 is used to amplify the second amplified signal and output the third amplified signal;

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

[0087] The dual-frequency millimeter-wave power amplifier based on a composite left-handed and right-handed transmission line provided in this invention utilizes the multi-resonance characteristics of the composite left-handed and right-handed transmission line structure through an input matching circuit. It employs a dual-frequency matching scheme combining a dual-frequency filter network designed based on an asymmetric composite left-handed and right-handed transmission line with an input matching branch. This achieves simultaneous fundamental frequency matching at two relatively far-distance frequency points, enabling the dual-frequency millimeter-wave power amplifier to exhibit simultaneous high-efficiency output at both frequencies. The circuit of this dual-frequency millimeter-wave power amplifier avoids the introduction of switching circuits, resulting in a simple structure that is easy to implement. It achieves stable dual-frequency high-efficiency characteristics without the need for additional control circuitry, and has broad application prospects in the field of wireless communication.

[0088] For ease of understanding, the various modules of the dual-frequency millimeter-wave power amplifier provided in the embodiments of the present invention will be described below.

[0089] Input matching circuit

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

[0091] Input matching branch 11 and dual-frequency filter network 12 based on asymmetric composite left and right hand transmission lines.

[0092] Specifically, from Figure 2 As can be seen from this, 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 terminal of resistor R1 is connected to the bias voltage VG1, and the second terminal is connected to the first terminal of microstrip line TL2.

[0096] The first terminal of capacitor C1 is connected to the first terminal of microstrip line TL2, and the second terminal is grounded.

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

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

[0099] The input matching sub-circuit may include:

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

[0101] The first terminal of capacitor C2 is grounded, and the second terminal is connected to the first terminal of microstrip line TL1.

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

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

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

[0105] Understandably, the input terminal of the input matching sub-circuit serves as the input terminal of the input matching branch 11, receiving the input radio frequency signal.

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

[0107] Capacitors C4, C5, and C6; microstrip line TL4, TL5, and TL6; among them,

[0108] The first terminal of capacitor C4 is connected to the first terminal of capacitor C6, and the second terminal is connected to the first terminal of microstrip line TL4.

[0109] The first terminal of capacitor C5 is connected to the first terminal of microstrip line TL5, and the second terminal is connected to the first terminal of capacitor C4.

[0110] The second terminal of 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] The first end of the microstrip line TL6 is connected to the first end of the capacitor C6, and the second end is connected to the second end of the capacitor C6.

[0113] The dual-frequency filter network 12 inserts filter zeros in parallel between the traditional matching networks, reducing the insertion loss of the matching networks. Simultaneously, to overcome the severe parasitic effects and layout difficulties of inductors in the traditional composite left- and right-handed unit structure in the millimeter-wave band, microstrip lines are used instead of inductors in the traditional composite left- and right-handed unit structure. This effectively reduces the insertion loss introduced by the dual-frequency input matching network and achieves a good filter passband. Furthermore, to flexibly adjust the filter zeros in the frequency band, the dual-frequency filter network based on the composite left- and right-handed transmission line is set as an asymmetric structure, i.e., the values ​​of the left-handed and right-handed units are different, thus overcoming the problem of difficulty in adjusting the filter zeros in the frequency band. For simulation results of the filtering effect of the filter network based on the left- and right-handed composite transmission line, please refer to [link to simulation results]. Figure 3 ,from Figure 3 As can be seen, a filtering band trap effect is effectively introduced between the center frequencies of 28GHz and 38GHz, while simultaneously achieving good dual-frequency matching. For simulation results of the input matching circuit provided in this embodiment of the invention, please refer to [link to simulation diagram]. Figure 4 ,from Figure 4 As can be seen, good matching can be achieved at the center frequency of 28GHz / 38GHz, and power transmission at 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 signal transmission loss. An RF system is a system that uses radio frequency signals for communication, signal processing, or power transmission. In an RF system, impedance is a crucial parameter in the signal transmission link. The characteristic impedance of an RF system typically refers to the input or output impedance of RF components such as transmission lines, antennas, and amplifiers. The characteristic impedance of an RF system can be 50 ohms or 75 ohms.

[0115] Understandably, the input matching circuit 1 provided in this embodiment of the invention utilizes the multi-resonance characteristics of a composite left-handed and right-handed transmission line structure. It employs a dual-frequency matching scheme combining a dual-frequency filter network designed based on an asymmetric composite left-handed and right-handed transmission line with an input matching branch. This achieves simultaneous fundamental frequency matching at two relatively far-distance frequency points, enabling the dual-frequency millimeter-wave power amplifier to exhibit simultaneous high-efficiency dual-frequency output. Simultaneously, the dual-frequency filter network, designed with a parallel asymmetric composite left-handed and right-handed transmission line, introduces a filter zero in the frequency band. This achieves good matching results with low loss at the two center frequencies. Furthermore, a band-depression effect is introduced between the two center frequencies, suppressing the transmission of intermediate spurious signals and filtering out spurious signals, thus achieving dual-band matched output.

[0116] Amplifier circuits at each stage

[0117] Each stage of the amplifier circuit amplifies the signal it receives.

[0118] Each stage of the amplifier circuit can include: a transistor and a grounded microstrip line; wherein,

[0119] The gate of the transistor serves as the input terminal of each stage 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 stage of the amplifier circuit.

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

[0121] Specifically, from Figure 1 As can be seen from the diagram, the first-stage amplifier circuit 2 may include transistor M1 and grounded microstrip line TL11; the second-stage amplifier circuit 4 may include transistor M2 and grounded microstrip line TL12; and the third-stage amplifier circuit 6 may include transistor M3 and grounded microstrip line TL16.

[0122] Understandably, for transistors in various stages of an amplifier circuit, the gate is the control terminal. By providing a bias voltage to the gate, the electric field strength inside the transistor can be controlled, thereby adjusting the transistor's switching state or amplification capability. The essence of the bias voltage is to ensure that passive devices are in a normal operating state, achieving control over input and output characteristics. In an amplifier circuit, an appropriate gate bias voltage can ensure that the transistor or other nonlinear components always exhibit DC-like electrical characteristics when the input signal changes, satisfying the correct transmission and amplification of information signals. Furthermore, the gate bias voltage can remove noise from the circuit, improve system reliability, accelerate transistor turn-on and turn-off, reduce turn-on and turn-off losses, reduce DI / DT, protect the transistor, and suppress EMI interference. The drain is the port from which current flows in the transistor. By providing a bias voltage to the drain, the transistor's amplification capability and output characteristics can be adjusted. In an amplifier circuit, an appropriate drain bias voltage can optimize the transistor's amplification effect, ensuring stable operation when amplifying audio signals and other tasks. In addition, the drain bias voltage also helps protect the power grid, preventing grid breakdown under abnormally high voltage conditions. The embodiments of the present invention provide appropriate bias voltages to the gate and drain of transistors in each stage of the amplifier circuit, which not only ensures the normal operation of transistors, but also optimizes circuit performance and improves the reliability and stability of the system.

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

[0124] The sizes of transistors M1, M2, and M3 can be selected based on requirements. First, the appropriate size of output stage transistor M3 can be determined. The size of transistor M3 can be chosen by balancing the ease of saturated output with dual-frequency matching, ensuring the feasibility of dual-frequency output matching. The sizes of transistors M1 and M2 can be determined based on the power drive ratio, ensuring that the power stage can be driven to saturation to achieve maximum power and efficiency, while preventing the drive stage from entering the fallback region prematurely, thus reducing overall linearity.

[0125] The dual-frequency millimeter-wave power amplifier provided in this embodiment of the invention can be designed based on 100nm GaN process, wherein the dimensions of transistor M1, transistor M2 and transistor M3 can be selected as 4×25μm, 4×50μm and 6×50μm respectively.

[0126] Inter-level matching circuit

[0127] Inter-level matching circuit 3 may include:

[0128] Capacitors C7, C8, C9, and C10; microstrip line TL7, TL8, TL9, and TL10; and resistor R2; among which,

[0129] The first terminal of capacitor C7 is connected to the bias voltage VD1, and the second terminal is grounded.

[0130] The first terminal of capacitor C8 is connected to the second terminal of microstrip line TL7, and the second terminal is connected to the first terminal of microstrip line TL8.

[0131] The first terminal of capacitor C9 is grounded, and the second terminal is connected to the second terminal of microstrip line TL8.

[0132] The first terminal of capacitor C10 is grounded, and the second terminal is connected to the second terminal of 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 of the inter-stage matching circuit 3.

[0134] The first end of microstrip line TL9 is connected to the second end of microstrip line TL8, and the second end of microstrip line TL8 is connected to the second end of 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 of the first-second stage matching circuit 3.

[0136] A bias voltage VG2 is connected to the first terminal of resistor R2.

[0137] The first-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, matching 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 transmitting the first amplified signal to the second-stage amplifier circuit 4.

[0138] Specifically, from Figure 1 As can be seen from the diagram, in the first-stage and second-stage matching circuit 3, capacitor C7 and microstrip line TL7 can form a first drain bias circuit, which provides a first drain bias voltage to the first-stage amplifier circuit 2; capacitor C10, microstrip line TL10 and resistor R2 can form a second gate bias circuit, which provides a second gate bias voltage to the second-stage amplifier circuit 4; capacitors C8 and C9, microstrip line TL8 and microstrip line TL9 can form a first-stage matching sub-circuit, which 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, thereby enabling the first-stage and second-stage matching circuit 3 to transmit the first amplified signal to the second-stage amplifier circuit 4.

[0139] Inter-level matching circuit

[0140] The inter-stage matching circuit 5 may include:

[0141] Capacitors C11, C12, C13, C14, and C15; microstrip line TL13, TL14, TL15, and TL17; and resistor R3; among which,

[0142] The first terminal of capacitor C11 is connected to the second terminal of microstrip line TL15, and the second terminal is connected to the first terminal of microstrip line TL13.

[0143] The first terminal of capacitor C12 is grounded, and the second terminal is connected to the second terminal of microstrip line TL13.

[0144] The first terminal of capacitor C13 is grounded, and the second terminal is connected to the second terminal of microstrip line TL14.

[0145] The first terminal of capacitor C14 is connected to the bias voltage VD2, and the second terminal is grounded.

[0146] The first terminal of capacitor C15 is connected to the second terminal of resistor R3, and the second terminal is grounded.

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

[0148] The second end of microstrip line TL14 is connected to the second end of 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 of the inter-stage 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 of the inter-stage matching circuit 5.

[0151] A bias voltage VG3 is connected to the first terminal of resistor R3.

[0152] The interstage 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. It 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 1As can be seen from the diagram, in the interstage matching circuit 5, capacitor C14 and microstrip line TL15 can form a second drain bias circuit, which provides a second drain bias voltage to the second stage amplifier circuit; capacitor C15, microstrip line TL17 and resistor R3 can form a third gate bias circuit, which provides a third gate bias voltage to the third stage amplifier circuit 6; capacitors C11, C12, and C13, microstrip line TL13 and microstrip line TL14 can form a second-stage matching sub-circuit, which 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, thereby enabling the interstage matching circuit 5 to transmit the second amplified signal to the third stage amplifier circuit 6.

[0154] Output matching circuit

[0155] The output matching circuit 7 may include:

[0156] Capacitors C16, C17, and C18; microstrip line TL18, TL19, and TL20; among them,

[0157] The first terminal of capacitor C16 is connected to the bias voltage VD3, and the second terminal is grounded.

[0158] The first terminal of capacitor C17 is connected to the first terminal of capacitor C18, and the second terminal is grounded.

[0159] The first end of capacitor C18 is connected to the second end of microstrip line TL19, and the second end serves as the output terminal of output matching circuit 7.

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

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

[0162] 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 RF system, and outputs the third amplified signal. To simplify the structure of output matching circuit 7, reduce power output stage losses, and improve the saturated output power and efficiency of the dual-band power amplifier, the design follows the principle of component reuse. Microstrip line TL20 and capacitor C16 are used to provide the third drain bias voltage to the third-stage amplifier circuit to isolate the RF signal, and also to match the conjugate of the load impedance of the third-stage amplifier circuit 6 to the characteristic impedance of the RF system, thus achieving component reuse and reducing layout area.

[0163] To facilitate demonstration of the beneficial effects of the dual-frequency millimeter-wave power amplifier provided in the embodiments of the present invention, simulations are performed below for both large and small signals.

[0164] For simulation results of the small-signal scattering parameters of the dual-frequency millimeter-wave power amplifier provided in this embodiment of the invention, please refer to [the relevant documentation / image]. Figure 5 For simulation results of small-signal scattering parameters of the dual-frequency millimeter-wave power amplifier in both frequency bands, please refer to the following figures. Figure 6 ;from Figure 5 and Figure 6 As can be seen, the dual-frequency millimeter-wave power amplifier can achieve simultaneous matching at center frequencies of 28GHz and 38GHz, with small-signal gains of 24dB and 21.8dB respectively. In the low-frequency band (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 (37-39GHz), the input reflection coefficient can be below -15dB, and the small-signal gain is greater than 21dB.

[0165] Please refer to the large-signal simulation results of the dual-frequency millimeter-wave power amplifier provided in this embodiment of the invention. Figure 7 .from Figure 7 As can be seen, the dual-frequency millimeter-wave power amplifier has a saturated output power greater than 31dBm at the center frequencies of 28GHz and 38GHz, and a power-added efficiency greater than 37% and 34% respectively, demonstrating good dual-frequency output characteristics.

[0166] This invention utilizes the multi-resonance characteristics of a composite left-handed and right-handed transmission line structure through an input matching circuit. It employs a dual-frequency matching scheme combining a dual-frequency filter network based on an asymmetric composite left-handed and right-handed transmission line design with an input matching branch. This achieves simultaneous fundamental frequency matching at two relatively far-distance frequency points, enabling the dual-frequency millimeter-wave power amplifier to exhibit simultaneous high-efficiency output at both frequencies. The circuit of this dual-frequency millimeter-wave power amplifier avoids the introduction of switching circuits, resulting in a simple and easy-to-implement structure. Stable dual-frequency high-efficiency characteristics can be achieved without additional control circuitry. Combining dual-frequency matching technology with circuit element multiplexing technology, a design scheme for a simple and low-loss dual-frequency millimeter-wave power amplifier is presented. This dual-frequency millimeter-wave power amplifier has a compact structure, is easy to implement, and offers the advantages of simultaneous dual-band output and high efficiency, making it promising for widespread application in modern wireless communication.

[0167] It should be noted that, in the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0168] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line, characterized in that, include: The circuit comprises an input matching circuit (1), a first-stage amplifier circuit (2), a first-stage and second-stage matching circuit (3), a second-stage amplifier circuit (4), a second-stage and third-stage matching circuit (5), a third-stage amplifier circuit (6), and an output matching circuit (7); among which, 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 RF system to the source impedance of the first stage amplifier circuit (2), and transmit the input RF 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 and right hand transmission line design. The first stage amplifier circuit (2) is used to amplify the input radio frequency signal and output the 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), 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 the second amplified signal; The interstage matching circuit (5) is used to provide a second drain bias voltage to the second stage amplifier circuit, 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 load impedance of the third stage amplifier circuit (6) to the characteristic impedance of the radio frequency system, and output the third amplified signal.

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

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

4. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line according to claim 3, characterized in that, The input matching sub-circuit includes: Capacitor C2, capacitor C3, microstrip line TL1, and microstrip line TL3; The first terminal of the capacitor C2 is grounded, and the second terminal is connected to the first terminal 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 the 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, serving 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. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line according to claim 1, characterized in that, The dual-frequency filter network (12) includes: Capacitors C4, C5, and C6; microstrip line TL4, TL5, and TL6; among them, The first terminal of capacitor C4 is connected to the first terminal of capacitor C6, and the second terminal is connected to the first terminal of microstrip line TL4. The first end of capacitor C5 is connected to the first end of microstrip line TL5, and the second end is connected to the first end of capacitor C4. The second terminal of capacitor C6 is grounded; The second end of the microstrip line TL4 is connected to the output end of the input matching branch (11) and serves as the output end of the input matching circuit (1); The second end of the microstrip line TL5 is open-circuited; The first end of the microstrip line TL6 is connected to the first end of the capacitor C6, and the second end is connected to the second end of the capacitor C6.

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

7. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line 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. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line according to claim 1, characterized in that, The inter-level matching circuit (3) includes: Capacitors C7, C8, C9, and C10; microstrip line TL7, TL8, TL9, and TL10; and resistor R2; among which, The first terminal of the capacitor C7 is connected to a bias voltage, and the second terminal 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 terminal of the capacitor C9 is grounded, and the second terminal is connected to the second terminal of the microstrip line TL8. The first terminal of the capacitor C10 is grounded, and the second terminal is connected to the second terminal 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 inter-stage 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 first-second stage matching circuit (3). The first terminal of the resistor R2 is connected to a bias voltage.

9. A dual-frequency millimeter-wave power amplifier based on a composite left- and right-handed transmission line according to claim 1, characterized in that, The inter-stage matching circuit (5) includes: Capacitors C11, C12, C13, C14, and C15; microstrip line TL13, TL14, TL15, and TL17; and resistor R3; among which, 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 terminal of the capacitor C12 is grounded, and the second terminal is connected to the second terminal of the microstrip line TL13. The first terminal of the capacitor C13 is grounded, and the second terminal is connected to the second terminal of the microstrip line TL14. The first terminal of the capacitor C14 is connected to a bias voltage, and the second terminal is grounded. The first terminal of capacitor C15 is connected to the second terminal of resistor R3, and the second terminal 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 inter-stage 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 inter-stage matching circuit (5). The first terminal of the resistor R3 is connected to a bias voltage.

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

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