Multistage monolithic microwave integrated circuit power amplifier

Abstract

The application provides a multi-stage monolithic microwave integrated circuit (MMIC) power amplifier, comprising: a radio frequency (RF) input end for receiving an RF signal; an amplification circuit module, comprising at least two cascade-connected transistor amplification circuit sub-modules, for cascade amplification and transmission of the RF signal; a bias filter circuit, having an output port connected to a gate voltage input end and a drain voltage input end of each transistor amplification circuit sub-module of the amplification circuit module, for providing a gate voltage and a drain voltage as a static operating point for each transistor amplification circuit sub-module of the amplification circuit module, and suppressing signal gain outside a working frequency band of the amplification circuit module through a filter network thereof; and an RF output end connected to an output end of a final-stage transistor amplification circuit sub-module of the amplification circuit module, for outputting an amplified RF signal of the amplification circuit module. The technical scheme of the application can improve the out-of-band stability of the multi-stage MMIC power amplifier.

Description

Technical Field

[0001] This invention relates to the field of radio frequency power amplifier technology, and more particularly to a multi-stage monolithic microwave integrated circuit power amplifier. Background Technology

[0002] Monolithic Microwave Integrated Circuit (MMIC) technology plays a crucial role in millimeter-wave circuit design. Power amplifiers, as the RF front-end modules in wireless communication systems, are decisive for the overall communication performance. With the increasing demand for millimeter waves in 5G and satellite communications, the operating frequencies of wireless communication systems are gradually expanding towards the Ku and Ka bands, which places higher demands on the performance of power amplifiers.

[0003] Multi-stage MMIC power amplifiers can address the higher gain requirements of millimeter-wave circuits, but they also impose a requirement for full-band stability. Current multi-stage MMIC power amplifiers, in order to maximize the gain characteristics of the transistors themselves, typically only ensure stability within the operating frequency band of each transistor stage, failing to achieve full-band stability and thus prone to instability outside the operating frequency band. Summary of the Invention

[0004] This invention provides a multi-stage monolithic microwave integrated circuit power amplifier to solve the defect of existing multi-stage MMIC power amplifiers that are prone to instability outside the operating frequency band, thereby improving the out-of-band stability of multi-stage MMIC power amplifiers.

[0005] This invention provides a multi-stage monolithic microwave integrated circuit power amplifier, comprising:

[0006] Radio frequency input terminal, used to receive radio frequency signals;

[0007] An amplifier circuit module includes at least two cascaded transistor amplifier circuit sub-modules. The input terminal of the first-stage transistor amplifier circuit sub-module of the amplifier circuit module is connected to the radio frequency input terminal. The amplifier circuit module is used to perform cascaded power amplification and transmission of the radio frequency signal.

[0008] A bias filter circuit is provided, the output port of which is connected to the gate voltage input terminal and drain voltage input terminal of each stage transistor amplifier sub-module of the amplifier circuit module. The bias filter circuit is used to provide the gate voltage and drain voltage as static operating points for each stage transistor amplifier sub-module of the amplifier circuit module, and to suppress the signal gain outside the operating frequency band of the amplifier circuit module through its filter network.

[0009] The radio frequency output terminal is connected to the output terminal of the final stage transistor amplifier circuit submodule of the amplifier circuit module, and is used to output the radio frequency signal amplified by the amplifier circuit module.

[0010] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the bias filter circuit includes at least one gate power supply circuit and at least one drain power supply circuit. The number of the gate power supply circuits is determined based on the number of gate voltage power supply terminals of the amplifier circuit module, and the number of the drain power supply circuits is determined based on the number of drain voltage power supply terminals of the amplifier circuit module. The gate power supply circuit and the drain power supply circuit include a filter network.

[0011] Each stage of the transistor amplifier circuit sub-module of the amplifier circuit module includes a gate voltage supply terminal and at least one drain voltage supply terminal. All gate voltage supply terminals of the amplifier circuit module are connected to the same gate power supply circuit, or the gate voltage supply terminals of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module are respectively connected to a gate power supply circuit. Each drain voltage supply terminal of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module is connected to a drain power supply circuit.

[0012] The gate power supply circuit is used to provide the gate voltage, and the drain power supply circuit is used to provide the drain voltage. The gate power supply circuit and the drain power supply circuit together determine the static operating point of each stage transistor amplifier sub-module of the amplifier circuit module, and suppress the signal gain outside the operating frequency band of the amplifier circuit module through the filter network.

[0013] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the drain power supply circuit includes a first power supply terminal, a drain voltage output terminal, a first filter resistor, a first filter capacitor, a second filter resistor, a second filter capacitor, a first passive microstrip line, a third filter capacitor, and an isolation inductor.

[0014] The first power supply terminal is used to connect to the first DC voltage source;

[0015] One end of the first filter resistor is connected to the first power supply terminal, and the other end is connected in series with the first filter capacitor and then grounded to form a first filter network.

[0016] The second filter resistor, the second filter capacitor and the first passive microstrip line are connected in parallel, with one end connected to the first power supply terminal and the other end connected to the first terminal of the isolation inductor to form a second filter network.

[0017] The first end of the isolation inductor is grounded through the third filter capacitor, and the second end of the isolation inductor is connected to the drain voltage output terminal.

[0018] The drain voltage output terminal serves as one of the output ports of the bias filter circuit and is connected to the drain voltage power supply terminal.

[0019] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the gate power supply circuit includes a second power supply terminal, a gate voltage output terminal, a third filter resistor, a fourth filter resistor, a fourth filter capacitor, a fifth filter capacitor, and a second passive microstrip line.

[0020] The second power supply terminal is used to connect to the second DC voltage source;

[0021] One end of the third filter resistor is connected to the second power supply terminal, and the other end is connected in series with the fourth filter capacitor and then grounded to form a third filter network.

[0022] The fourth filter resistor, the fifth filter capacitor, and the second passive microstrip line are connected in parallel, with one end connected to the second power supply terminal and the other end connected to the gate voltage output terminal to form the fourth filter network.

[0023] The gate voltage output terminal serves as one of the output ports of the bias filter circuit and is connected to the gate voltage power supply terminal.

[0024] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the voltages used by the gate power supply circuit and the drain power supply circuit are different.

[0025] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the first-stage transistor amplifier circuit sub-module of the amplifier circuit module includes an input matching circuit, a first-stage transistor amplifier unit circuit, and a first-stage inter-matching circuit.

[0026] The input matching circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the radio frequency input terminal, and the first output terminal is connected to the input terminal of the first-stage transistor amplifier unit circuit. The input matching circuit is used to match the impedance of the signal source transmitting the radio frequency signal with the input impedance of the first-stage transistor amplifier circuit submodule, and to superimpose a positive slope frequency response curve on the radio frequency signal received by the radio frequency input terminal.

[0027] The first-stage transistor amplifier unit circuit is used to amplify the radio frequency signal input from the radio frequency input terminal in the first stage.

[0028] The input terminal of the first-stage matching circuit is connected to the output terminal of the first-stage transistor amplifier unit circuit. The first-stage matching circuit is used to perform impedance matching between the first-stage transistor amplifier unit circuit and the next-stage transistor amplifier circuit submodule of the first-stage transistor amplifier circuit submodule.

[0029] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the input matching circuit includes a matching inductor, a matching resistor, a first matching capacitor, a second matching capacitor, a third passive microstrip line, and a fourth passive microstrip line;

[0030] One end of the matching inductor is connected to the radio frequency input terminal, and the other end is grounded;

[0031] The matching resistor, the first matching capacitor, and the third passive microstrip line are connected in parallel. One end of the parallel connection is connected to the RF input terminal, and the other end is connected in series with the second matching capacitor and the fourth passive microstrip line and then connected to the input terminal of the first stage transistor amplifier unit circuit.

[0032] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the final stage transistor amplifier circuit sub-module of the amplifier circuit module includes a final stage transistor amplifier unit circuit and an output power coupling circuit.

[0033] The input terminal of the final stage transistor amplifier unit circuit is connected to the output terminal of the previous stage transistor amplifier circuit submodule of the final stage transistor amplifier circuit submodule. The final stage transistor amplifier unit circuit is used to amplify the signal output by the previous stage transistor amplifier circuit submodule of the final stage transistor amplifier circuit submodule.

[0034] The output power coupling circuit includes a coupling input terminal and a coupling output terminal. The coupling input terminal is connected to the output terminal of the final stage transistor amplifier unit circuit, and the coupling output terminal is connected to the radio frequency output terminal. The output power coupling circuit is used to convert the load impedance of the back-end load connected to the radio frequency output terminal to match the output impedance of the final stage transistor amplifier unit circuit, and to couple the signal output by the final stage transistor amplifier unit circuit to the radio frequency output terminal.

[0035] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein the intermediate stage transistor amplifier circuit sub-module of the amplifier circuit module includes an intermediate stage transistor amplifier unit circuit and an intermediate stage inter-stage matching circuit.

[0036] The input terminal of the intermediate stage transistor amplifier unit circuit is connected to the output terminal of the preceding stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule. The intermediate stage transistor amplifier unit circuit is used to amplify the signal output by the preceding stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule.

[0037] The intermediate stage matching circuit is used to perform impedance matching on the intermediate stage transistor amplifier unit circuit and the next stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule.

[0038] According to the present invention, a multi-stage monolithic microwave integrated circuit power amplifier is provided, wherein each transistor amplification unit circuit includes at least one transistor, and the number of the at least one transistor is determined based on the target output power of the amplification circuit module.

[0039] The multi-stage monolithic microwave integrated circuit power amplifier provided by this invention, by setting a bias filter circuit on the periphery of the amplifier circuit module, and connecting the bias filter output port of the bias filter circuit to the gate voltage input terminal and drain voltage input terminal of each stage transistor amplifier sub-module of the amplifier circuit module, can provide gate voltage and drain voltage as static operating point for each stage transistor amplifier sub-module of the amplifier circuit module. By suppressing the signal gain outside the operating frequency band of the amplifier circuit module through the filter network in the bias filter circuit, the burst gain outside the operating frequency band of the amplifier circuit module can be reduced, thereby improving the out-of-band stability of the multi-stage MMIC power amplifier. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is one of the structural schematic diagrams of the MMIC power amplifier provided by the present invention;

[0042] Figure 2 This is a schematic diagram of the drain power supply circuit provided by the present invention;

[0043] Figure 3 This is a schematic diagram of the gate power supply circuit provided by the present invention;

[0044] Figure 4 This is a schematic diagram of the structure of the first-stage transistor amplifier circuit submodule of the amplifier circuit module provided by the present invention;

[0045] Figure 5 This is a schematic diagram of the input matching circuit provided by the present invention;

[0046] Figure 6 This is a schematic diagram of the final stage transistor amplifier circuit submodule of the amplifier circuit module provided by the present invention;

[0047] Figure 7 This is a schematic diagram of the output power coupling circuit provided by the present invention;

[0048] Figure 8 This is the second schematic diagram of the structure of the multi-stage MMIC power amplifier provided by the present invention;

[0049] Figure 9 This is a schematic diagram of the gain variation curve within the operating frequency band of the multi-stage MMIC power amplifier provided by the present invention.

[0050] Figure 10 This is a schematic diagram of the gain variation curve outside the operating frequency band of the multi-stage MMIC power amplifier provided by the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] In millimeter-wave circuit design, active and passive components can be integrated on a dielectric substrate using semiconductor processes to form stable, highly reliable, and long-life millimeter-wave circuits. SUB-6GHz refers to electromagnetic waves with frequencies below 6GHz. With the depletion of SUB-6GHz spectrum resources and the increasing demands for 5G and satellite communications, the operating frequencies of wireless communication systems are gradually expanding towards the Ku and Ka bands. This presents a broad application prospect for designing wideband, miniaturized, high-capacity, and high-speed communication devices. The Ku band refers to a frequency band lower than the K-band under the IEEE 521-2002 standard, while the Ka band refers to a frequency band higher than the K-band.

[0053] As a radio frequency front-end module in wireless communication, the power amplifier plays a decisive role in the overall wireless communication performance of the system. Research on power amplifiers in related technologies mainly focuses on high efficiency, high power, and large bandwidth. Due to the inherent characteristics of transistors, the maximum obtainable gain of a power amplifier decreases as the frequency increases, resulting in poor gain flatness over a wide operating frequency band. Consequently, the power and efficiency fluctuations of the amplification device become larger over a wide bandwidth, affecting the overall system performance.

[0054] Multistage power amplifiers can adapt to the various gain requirements and even higher gain demands of millimeter-wave circuits. However, variations in design, fabrication, and testing environments can induce instability in power amplifiers. Furthermore, multistage power amplifiers need to ensure unconditional stability across all stages throughout the entire frequency band. Therefore, designing a globally stable power amplifier has become a key research focus. In related technologies, the design of multistage power amplifiers typically only ensures stability within the operating frequency band of each transistor to maximize its inherent gain characteristics, thus failing to achieve full-band stability. For cascaded amplifiers, based on the inherent gain characteristics of transistors, they exhibit high gain at low frequencies, which decreases as the frequency increases. Within the operating frequency band, if the output matching network, input matching network, and interstage matching network lack frequency selectivity, the transistors can pass both in-band and out-of-band signals, resulting in a very high ideal low-frequency gain for the cascaded transistors. If the output matching network, input matching network, and inter-stage matching network have frequency selectivity, then the gain loss of signals passing through the operating frequency band is small and the throughput is good. Although there is suppression outside the band, it is difficult to guarantee that all out-of-band gain is well suppressed. There may be situations where the gain of some low-frequency signals is still very high, that is, there may be a situation where a certain frequency band outside the operating frequency band is unstable.

[0055] Based on this, embodiments of the present invention provide a multi-stage monolithic microwave integrated circuit (MMIC) power amplifier. A bias filter circuit is provided around an amplifier circuit module including at least two cascaded transistor amplifier circuit sub-modules. The bias filter output port of the bias filter circuit is connected to the gate voltage input terminal and drain voltage input terminal of each stage transistor amplifier circuit sub-module of the amplifier circuit module. The gate voltage and drain voltage of each stage transistor amplifier circuit sub-module of the amplifier circuit module are provided as static operating points. The signal gain outside the operating frequency band of the amplifier circuit module is suppressed by the filter network in the bias filter circuit.

[0056] The following is combined Figures 1-10 The MMIC power amplifier of the present invention will be described.

[0057] Figure 1An exemplary schematic diagram of one of the structures of the MMIC power amplifier provided in an embodiment of the present invention is shown, with reference to... Figure 1 As shown, the MMIC power amplifier may include an RF input terminal IN, an amplifier circuit module 10, a bias filter circuit 20, and an RF output terminal OUT. Specifically: the RF input terminal IN is used to receive RF signals; the amplifier circuit module 10 includes at least two cascaded transistor amplifier circuit sub-modules, the input terminal of the first-stage transistor amplifier circuit sub-module of the amplifier circuit module 10 is connected to the RF input terminal IN, and the amplifier circuit module 10 is used to cascade amplify and transmit the RF signal received at the RF input terminal IN; the output port D of the bias filter circuit 20 is connected to the gate voltage input terminal A1 and the drain voltage input terminal B1 of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module 10, and the bias filter circuit 20 is used to provide the gate voltage and drain voltage as the static operating point for each stage of the transistor amplifier circuit sub-module of the amplifier circuit module 10, and to suppress the signal gain outside the operating frequency band of the amplifier circuit module 10 through its filtering network; the RF output terminal OUT is connected to the output terminal of the final stage transistor amplifier circuit sub-module of the amplifier circuit module 10, and is used to output the amplified RF signal from the amplifier circuit module 10.

[0058] The MMIC power amplifier provided in this embodiment of the invention provides gate voltage, drain voltage, and quiescent operating point for each stage of the transistor amplifier sub-module by setting a bias filter circuit around the amplifier circuit module and connecting the bias filter output port of the bias filter circuit to the gate voltage input terminal and drain voltage input terminal of each stage of the transistor amplifier sub-module. By filtering out sudden signals outside the operating frequency band of the amplifier circuit module through the bias filter circuit, the burst gain outside the operating frequency band of the amplifier circuit module can be reduced, thereby improving the out-of-band stability of the multi-stage MMIC power amplifier.

[0059] based on Figure 1In a corresponding embodiment of the multi-stage MMIC power amplifier, in one example embodiment, the bias filter circuit 20 may include at least one gate power supply circuit and at least one drain power supply circuit, both of which include a filter network. The gate power supply circuit provides a gate voltage, and the drain power supply circuit provides a drain voltage. Together, the gate and drain power supply circuits determine the static operating point of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module 10, and suppress signal gain outside the operating frequency band of the amplifier circuit module 10 through their filter networks. The number of gate power supply circuits can be determined based on the number of gate voltage supply terminals of the amplifier circuit module 10, and the number of drain power supply circuits can be determined based on the number of drain voltage supply terminals of the amplifier circuit module 10. For example, each stage of the transistor amplifier circuit submodule of the amplifier circuit module 10 may include a gate voltage supply terminal and at least one drain voltage supply terminal. All gate voltage supply terminals of the amplifier circuit module 10 may be connected to the same gate power supply circuit, and each drain voltage supply terminal of each stage of the transistor amplifier circuit submodule of the amplifier circuit module 10 may be connected to a drain power supply circuit. In this case, the bias filter circuit 20 may include one gate power supply circuit and the same number of drain power supply circuits as the total number of drain voltage supply terminals in the amplifier circuit module 10. For example, if the amplifier circuit module 10 includes three stages of transistor amplifier circuit submodules, and each stage of the transistor amplifier circuit submodule includes one gate voltage supply terminal and two drain voltage supply terminals, the bias filter circuit 20 may include three gate power supply circuits and six drain power supply circuits.

[0060] Figure 2 An exemplary schematic diagram of the drain power supply circuit provided in an embodiment of the present invention is shown, with reference to... Figure 2As shown, the drain power supply circuit may include a first power supply terminal U1, a drain voltage output terminal V1, a first resistor R1, a first filter capacitor C1, a second filter resistor R2, a second filter capacitor C2, a first passive microstrip line W1, a third filter capacitor C3, and an isolation inductor L1. The first and second filter resistors R1 and R2 may be metal film resistors, the first and second capacitors C1 and C2 may be metal-insulator-metal (MIM) capacitors, and the isolation inductor L1 may be an on-chip inductor. The first power supply terminal U1 is connected to the first DC voltage source, which provides the first voltage signal. One end of the first filter resistor R1 is connected to the first power supply terminal U1, and the other end is connected in series with the first filter capacitor C1 and then grounded to form a first filter network. The second filter resistor R2, the second filter capacitor C2, and the first passive microstrip line W1 are connected in parallel, with one end connected to the first power supply terminal U1 and the other end connected to the first end of the isolation inductor L1 to form a second filter network. The parallel second filter resistor R2, the second filter capacitor C2, and the first passive microstrip line W1 can be equivalent to a lossy RLC circuit. The first end of the isolation inductor L1 is grounded through the third capacitor, and the second end of the isolation inductor L1 is connected to the drain voltage output terminal V1. The drain voltage output terminal V1 serves as a terminal of the output port D of the bias filter circuit 20 and is connected to the drain voltage power supply terminal in the amplifier circuit module 10.

[0061] Figure 3 An exemplary schematic diagram of the gate power supply circuit provided in an embodiment of the present invention is shown, with reference to... Figure 3 As shown, the gate power supply circuit includes a second power supply terminal U2, a gate voltage output terminal V2, a third filter resistor R3, a fourth filter resistor R4, a fourth filter capacitor C4, a fifth filter capacitor C5, and a second passive microstrip line W2. The third filter resistor R3 and the fourth filter resistor R4 can be metal thin-film resistors, and the fourth filter capacitor C4 and the fifth filter capacitor C5 can be MIM capacitors. The second power supply terminal U2 is used to connect to the second DC voltage source, which provides the second voltage signal. One end of the third filter resistor R3 is connected to the second power supply terminal U2, and the other end is connected in series with the fourth filter capacitor C4 and grounded to form the third filter network. The fourth filter resistor R4, the fifth filter capacitor C5, and the second passive microstrip line W2 are connected in parallel, with one end connected to the second power supply terminal U2 and the other end connected to the gate voltage output terminal V2 to form the fourth filter network. The parallel fourth filter resistor R4, the fifth filter capacitor C5, and the second passive microstrip line W2 can be equivalent to a lossy RLC circuit. The gate voltage output terminal V2 serves as a terminal of the output port of the bias filter circuit 20 and is connected to the gate voltage power supply terminal in the amplifier circuit module 10.

[0062] based on Figure 2 and Figure 3 The first power supply terminal U1 of the gate power supply circuit is connected to the first DC voltage source, and the second power supply terminal U2 of the drain power supply circuit is connected to the second DC voltage source. The first DC voltage source and the second DC voltage source are two different power sources and can provide two different voltage signals. The bias filter circuit 20 provides the same gate voltage to all gate voltage input terminals of the amplifier circuit module 10 through the gate power supply circuit, and provides the same drain voltage to all drain voltage input terminals of the amplifier circuit module 10 through the drain power supply circuit.

[0063] based on Figure 1 In one example embodiment, the multi-stage MMIC power amplifier corresponding to the embodiments is... Figure 4 An exemplary diagram illustrates the structure of the first-stage transistor amplifier circuit submodule of the amplifier circuit module provided in an embodiment of the present invention, with reference to... Figure 4 As shown, the first-stage transistor amplifier submodule of the amplifier circuit module may include an input matching circuit, a first-stage transistor amplifier unit circuit, and a first-stage inter-stage matching circuit. The input matching circuit includes a first input terminal E1 and a first output terminal E2. The first input terminal E1 is connected to the RF input terminal IN, and the first output terminal E2 is connected to the input terminal E3 of the first-stage transistor amplifier unit circuit. This input matching circuit is used to match the impedance of the signal source transmitting the RF signal with the input impedance of the first-stage transistor amplifier submodule and to superimpose a positive slope frequency response curve onto the RF signal received at the RF input terminal IN. The first-stage transistor amplifier unit circuit is used to amplify the RF signal input at the RF input terminal IN in the first stage. The input terminal E5 of the first-stage inter-stage matching circuit is connected to the output terminal E4 of the first-stage transistor amplifier unit circuit, and the output terminal E6 is connected to the input terminal of the next-stage transistor amplifier submodule of the first-stage transistor amplifier submodule. This first-stage inter-stage matching circuit is used to perform impedance matching between the first-stage transistor amplifier unit circuit and the next-stage transistor amplifier submodule of the first-stage transistor amplifier submodule.

[0064] based on Figure 4 The first-stage transistor amplifier circuit submodule corresponding to the embodiment, Figure 5 An exemplary schematic diagram of the input matching circuit provided in an embodiment of the present invention is shown, with reference to... Figure 5As shown, the input matching circuit includes a matching inductor L2, a matching resistor R5, a first matching capacitor C6, a second matching capacitor C7, a third passive microstrip line W3, and a fourth passive microstrip line W4. The matching resistor R5 can be a metal film resistor, the first and second matching capacitors C6 and C7 can be MIM capacitors, and the matching inductor L2 can be an on-chip inductor. One end of the matching inductor L2 is connected to the RF input terminal IN, and the other end is grounded to prevent electrostatic discharge (ESD). The matching resistor R5, the first matching capacitor C6, and the third passive microstrip line W3 are connected in parallel, with one end connected to the RF input terminal IN, and the other end connected in series with the second matching capacitor C7 and the fourth passive microstrip line W4, then connected to the output terminal E2 of the input matching circuit. This output terminal E2 is then connected to the input terminal E3 of the first-stage transistor amplifier unit circuit. This input matching circuit can convert the 50-ohm input source impedance to the input port of the first-stage transistor amplifier unit circuit, providing the impedance required by the first-stage transistor amplifier unit circuit, thus achieving input impedance matching. Meanwhile, the matching resistor R5 and the first matching capacitor C6 can form an integrating circuit network, generating a positive slope frequency response curve superimposed on the RF signal received at the RF input terminal IN, ensuring that the gain of the amplifier circuit module 10 tends to be flat throughout the entire operating frequency band. The parallel connection of the third passive microstrip line W3, the first matching capacitor C6, and the matching resistor R5 can be equivalent to a lossy RLC circuit.

[0065] based on Figure 1 In one example embodiment, the multi-stage MMIC power amplifier corresponding to the embodiments is... Figure 6 An exemplary diagram illustrates the structure of the final-stage transistor amplifier circuit submodule of the amplifier circuit module provided in an embodiment of the present invention, with reference to... Figure 6 As shown, the final-stage transistor amplifier circuit submodule may include a final-stage transistor amplifier unit circuit and an output power coupling circuit. The input terminal F1 of the final-stage transistor amplifier unit circuit is connected to the output terminal of the preceding stage transistor amplifier circuit submodule, and this final-stage transistor amplifier unit circuit amplifies the signal output from the preceding stage transistor amplifier circuit submodule. The output power coupling circuit includes a coupling input terminal F3 and a coupling output terminal F4. The coupling input terminal F3 is connected to the output terminal F2 of the final-stage transistor amplifier unit circuit, and the coupling output terminal F4 is connected to the RF output terminal OUT. This output power coupling circuit converts the load impedance of the downstream load connected to the RF output terminal OUT to match the output impedance of the final-stage transistor amplifier unit circuit, and couples the signal output from the final-stage transistor amplifier unit circuit to the RF output terminal.

[0066] For example, the output power coupling circuit can be implemented based on passive microstrip lines and MIM capacitors. For instance, Figure 7An exemplary schematic diagram of the output power coupling circuit provided in an embodiment of the present invention is shown, with reference to... Figure 7 As shown, taking a final-stage transistor amplifier unit circuit comprising four transistors as an example, the drain terminals of these four transistors are a1, a2, a3, and a4, respectively. The area covered by the cross-section line represents a passive microstrip line. The drain terminals a1 and a2, and a3 and a4, can be coupled and synthesized through different passive microstrip lines. The resulting coupling and synthesis is then coupled and synthesized again through a wider passive microstrip line. The final coupling and synthesis result is output through the RF output terminal OUT. Figure 7 In the diagram, the dashed coil 71 represents the ground terminal, and the dashed coil 72 can be equivalent to an inductor connected in series with a capacitor and then grounded. The ellipse 721 represents a capacitor, which can be a MIM capacitor. This capacitor can be grounded through an on-chip via. The inductor can be replaced by the horizontal passive microstrip line in the dashed coil 72.

[0067] based on Figure 7 In circuit design, the microstrip line used in the output power coupling circuit can be as wide as possible to reduce additional power dissipation. On the one hand, this can meet the requirement of achieving low insertion loss, and on the other hand, it can provide sufficient current carrying capacity to prevent the chip from burning out due to excessive current caused by high power output.

[0068] based on Figure 1 In one example embodiment of the multi-stage MMIC power amplifier corresponding to the embodiment, the intermediate stage transistor amplifier circuit submodule of the amplifier circuit module 10 may include an intermediate stage transistor amplifier unit circuit and an intermediate stage inter-stage matching circuit. The input terminal of the intermediate stage transistor amplifier unit circuit is connected to the output terminal of the preceding stage transistor amplifier circuit submodule, and this intermediate stage transistor amplifier unit circuit is used to amplify the signal output by the preceding stage transistor amplifier circuit submodule. The intermediate stage inter-stage matching circuit is used to perform impedance matching between the intermediate stage transistor amplifier unit circuit and the following stage transistor amplifier circuit submodule.

[0069] Based on the above embodiments, each stage of the transistor amplifier circuit sub-module of the amplifier circuit module 10 includes at least one transistor in its transistor amplifier unit circuit. The number and size of the transistors can be determined based on the target output power of the amplifier circuit module 10. For example, if the designed amplifier circuit module 10 cascades three stages of transistor amplifier circuit sub-modules, according to the target output power, the first stage transistor amplifier circuit sub-module can be designed to include one transistor, the second stage transistor amplifier circuit sub-module to include two transistors, and the third stage transistor amplifier circuit sub-module to include four transistors.

[0070] based on Figures 1 to 7Regarding the content of the corresponding embodiment, the following example uses an amplifier circuit module that includes three cascaded transistor amplifier circuit sub-modules. Figure 8 The multi-stage MMIC power amplifier provided in the embodiments of the present invention will be further illustrated by examples.

[0071] Figure 8 A second schematic diagram of the structure of the multi-stage MMIC power amplifier provided in an embodiment of the present invention is shown, with reference to... Figure 8 As shown, the multi-stage MMIC power amplifier's amplification circuit module includes three cascaded transistor amplifier circuit sub-modules, capable of multi-stage cascaded amplification of RF signals. The number and size of transistors in each stage of the transistor amplifier circuit sub-module can be selected according to the target output power. Specifically, the first-stage transistor amplifier circuit sub-module includes an input matching circuit 811, a first-stage transistor amplifier unit circuit 812, and a first-stage inter-stage matching circuit 813. The first-stage transistor amplifier unit circuit 812 includes one transistor G1, which can be, for example, a 4×50μm transistor. This first-stage transistor amplifier unit circuit 812 can perform the first-stage amplification of the RF signal received at the RF input terminal IN. The second-stage transistor amplifier circuit sub-module includes a second-stage transistor amplifier unit circuit 821 and a second-stage inter-stage matching circuit 822. The second-stage transistor amplifier unit circuit 821 includes two transistors, G2 and G3. The parallel transistors, such as 4×50μm transistors, form the second-stage transistor amplifier circuit 821, which amplifies the RF signal after the first stage amplification. The third-stage transistor amplifier circuit submodule includes a third-stage transistor amplifier circuit 831 and an output power coupling circuit 832. The third-stage transistor amplifier circuit 831 includes four parallel transistors: G4, G5, G6, and G7, which can be, for example, 4×75μm transistors. This third-stage transistor amplifier circuit 831 amplifies the RF signal after the second stage amplification. For each stage of the transistor amplifier circuit, an RC parallel network is set near the gate of the transistor, such as the RC parallel network composed of resistor R and inductor C in the first-stage transistor amplifier circuit 812, which ensures the stability of the MMIC power amplifier within the operating frequency band.

[0072] The first-stage matching circuit 813 and the second-stage matching circuit 822 are designed using passive components, including on-chip microstrip lines, MIM capacitors, and on-chip inductors. On-chip inductors can be replaced by on-chip microstrip lines. During the design process, the insertion loss can be minimized and the matching bandwidth maximized by adjusting the bandwidth of the microstrip lines, MIM capacitors, and on-chip inductors, thereby improving the overall gain of the multi-stage MMIC power amplifier. The first-stage matching circuit 813 can bias the output of transistor G1 and the power input points of the gate inputs of transistors G2 and G3 in the second-stage transistor amplifier unit circuit 821, achieving impedance matching between the first-stage transistor amplifier unit circuit 812 and the second-stage transistor amplifier unit circuit 821. The second-stage matching circuit 822 can bias the outputs of transistors G2 and G3 and the power input points of the gate inputs of the four transistors in the third-stage transistor amplifier unit circuit 831, achieving impedance matching between the second-stage transistor amplifier unit circuit 821 and the third-stage transistor amplifier unit circuit 831.

[0073] The output power coupling circuit 832 can be implemented using passive microstrip lines, MIM capacitors, and inductors, with the inductor also implemented using passive microstrip lines. In the circuit design, the width of the passive microstrip line used in the output power coupling circuit 832 can be designed to be as wide as possible to reduce additional power dissipation, meet the requirement of low insertion loss, and provide sufficient current carrying capacity to prevent chip burnout due to excessive current from high-power output. This output power coupling circuit 832 can convert the 50-ohm on-resistance of the load connected to the RF output terminal OUT into the required output impedance at the output port of the third-stage transistor amplifier unit circuit 831, achieving output impedance matching. Simultaneously, the output power coupling circuit 832 can couple the output power of the four transistors in the third-stage transistor amplifier unit circuit 831 in pairs, and the coupled two signals are then coupled again and sent to the RF output terminal OUT, realizing power combining and power output of the amplified RF signal from the third-stage transistor amplifier unit circuit 831. The output power coupling circuit 832 can transmit the drain voltage output by the drain power supply circuit 844 to the drain terminal of transistor G5, and can transmit the drain voltage output by the drain power supply circuit 843 to the drain terminal of transistor G6, providing the bias access point of the third-stage transistor amplifier unit circuit 831, that is, providing the drain voltage.

[0074] This MMIC power amplifier is designed with five drain power supply circuits and one gate power supply circuit forming a bias filter circuit. The drain voltage output terminal of drain power supply circuit 841 is connected to the drain terminal of transistor G1, providing drain voltage for transistor G1. The drain terminals of transistors G3 and G2 serve as the two drain voltage power supply terminals of the second-stage transistor amplification unit circuit 821, and are connected to the drain voltage output terminals of drain power supply circuits 842 and 845, respectively, providing drain voltage. The drain voltage output terminal of drain power supply circuit 844 is connected to the drain terminal of transistor G4, providing drain voltage for transistor G4 and supplying drain voltage to transistor G5 through output power coupling circuit 832. The drain voltage output terminal of drain power supply circuit 843 is connected to the drain terminal of transistor G7, providing drain voltage for transistor G7 and supplying drain voltage to transistor G6 through output power coupling circuit 832. The gate voltage output terminal of the gate power supply circuit 851 is connected to the gate terminals of all transistors in the MMIC power amplifier, providing gate voltages for each transistor. In this MMIC power amplifier, the designed five drain power supply circuits and one gate power supply circuit provide the quiescent operating point for the three-stage cascaded amplifier module. All drain voltages are the same, all gate voltages are the same, but the voltage sources of all drain power supply circuits are different from the voltage source of the gate power supply circuit 851; that is, voltage U1 and voltage U2 are different.

[0075] The radio frequency (RF) signal is input to the input matching circuit 811 through the RF input terminal IN. The input matching circuit 811 transforms the 50-ohm impedance of the RF signal source to the impedance required by the first-stage transistor amplifier circuit 812, and superimposes a positive slope frequency response curve onto the RF signal to ensure that the gain within the operating frequency band tends to be flat. The RF signal output from the input matching circuit 811 is sequentially amplified by the first-stage transistor amplifier circuit 812, the second-stage transistor amplifier circuit 821, and the third-stage transistor amplifier circuit 831. The amplified RF signal is then power-combined by the output power coupling circuit 832 and sent to the RF output terminal OUT for output. During the operation of the amplifier circuit module, each stage of the transistor amplifier unit circuit can increase the transistor input impedance through the RC parallel network connected to the front end of its transistor gate, achieving conditional stability within the operating frequency band. That is, the input impedance of the transistor can be increased to a specific range to move away from the unstable source impedance region, so that the gain within the operating frequency band is stabilized within a certain range. Moreover, the drain power supply circuit and gate power supply circuit designed for each stage of the transistor amplifier unit circuit can supply power to each stage of the transistor amplifier unit circuit. Based on the characteristic that high-frequency signals tend to pass through capacitors while low-frequency signals tend to pass through resistors, for radio frequency signals outside the operating frequency band, the RC series network in the drain power supply circuit and gate power supply circuit, as well as the equivalent RLC parallel network of resistors, capacitors and passive microstrip lines, can change the source impedance and load impedance of the transistor to dissipate signals outside the operating frequency band, suppress signals with higher gain that may appear outside the operating frequency band, and make the radio frequency signals outside the operating frequency band tend to be stable, thus improving the stability of signals outside the operating frequency band. Meanwhile, an isolation inductor is designed in the drain power supply circuit. Based on the function of the inductor to pass DC and block AC, it can store AC signal energy. As the frequency increases, its impedance value will also increase. This can ensure that the signal within the working frequency band will not leak out from the isolation inductor. The provided DC voltage U1 can supply power to the drain of the transistor through the isolation inductor. In this way, the bias filter circuit has little or no impact on the performance of the amplifier circuit module within the working frequency band, and does not affect the signal operation within the working frequency band.

[0076] right Figure 8 The performance of the multi-stage MMIC power amplifier shown was verified, and the stability of its signal within and outside the operating frequency band was obtained. Specifically, Figure 9 An exemplary diagram illustrates the gain variation curve within the operating frequency band of the multi-stage MMIC power amplifier provided in an embodiment of the present invention. (Refer to...) Figure 9 As shown, this multi-stage MMIC power amplifier exhibits relatively stable gain in the 27GHz to 32GHz frequency band, with a flatness of up to 1.8dB, and good input matching. Figure 10An exemplary diagram illustrates the gain variation curve outside the operating frequency band of the multi-stage MMIC power amplifier provided in an embodiment of the present invention, with reference to... Figure 10 As shown, the operating frequency band of the amplifier circuit module is 27GHz to 32GHz. If the bias filter circuit provided by this invention is not set around the amplifier circuit module, the gain curve is curve ①. In the out-of-band low-frequency band of 8GHz to 12GHz, the gain decreases and becomes unstable near 10GHz, oscillating. The gain near 10GHz undergoes a sudden change, becoming very high, which can easily burn out the circuit components. However, for the multi-stage MMIC power amplifier provided by this invention, by adding a bias filter circuit around the amplifier circuit module, its gain curve becomes curve ②. The sudden gain is well suppressed, and the curve near the 8-12GHz out-of-band frequency band becomes stable from a potentially unstable state, greatly improving stability.

[0077] The multi-stage MMIC power amplifier provided in this invention adopts MMIC integrated chip technology, which has advantages such as easy integration, miniaturization, and wide bandwidth. The provided technical solution can be widely used in applications such as optimizing the flatness of multi-stage MMIC power amplifiers and improving out-of-band stability. This multi-stage MMIC power amplifier adds a bias filter circuit to the periphery of the amplifier circuit module, which includes multi-stage cascaded transistor amplifier circuit sub-modules. This can enhance the stability of the circuit output gain and the operating stability of the amplifier circuit module while ensuring that the inherent performance indicators of the amplifier circuit module are met, thereby improving the reliability and practicality of the integrated amplifier chip. Furthermore, the input matching circuit of the multi-stage MMIC power amplifier provided in this invention is located at the RF input terminal, and its addition has a very small impact on the power and efficiency of the amplifier circuit module itself. On the other hand, the bias filter circuit of the multi-stage MMIC power amplifier provided in this embodiment of the invention has minimal impact on the performance indicators of the amplifier circuit module itself within the band. It can suppress the signal gain in areas where instability may occur in the low-frequency band outside the operating frequency band, improve the gain stability outside the operating frequency band, and even when the amplifier circuit module chip has been processed but cannot be integrated on the chip, it can be implemented on the circuit board on which the chip is mounted.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-stage monolithic microwave integrated circuit power amplifier, characterized in that, include: Radio frequency input terminal, used to receive radio frequency signals; An amplifier circuit module includes at least two cascaded transistor amplifier circuit sub-modules. The input terminal of the first-stage transistor amplifier circuit sub-module of the amplifier circuit module is connected to the radio frequency input terminal. The amplifier circuit module is used to perform cascaded power amplification and transmission of the radio frequency signal. A bias filter circuit is provided, the output port of which is connected to the gate voltage input terminal and drain voltage input terminal of each stage transistor amplifier sub-module of the amplifier circuit module. The bias filter circuit is used to provide the gate voltage and drain voltage as static operating points for each stage transistor amplifier sub-module of the amplifier circuit module, and to suppress the signal gain outside the operating frequency band of the amplifier circuit module through its filter network. The radio frequency output terminal is connected to the output terminal of the final stage transistor amplifier circuit sub-module of the amplifier circuit module, and is used to output the radio frequency signal amplified by the amplifier circuit module.

2. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 1, characterized in that, The bias filter circuit includes at least one gate power supply circuit and at least one drain power supply circuit. The number of gate power supply circuits is determined based on the number of gate voltage power supply terminals of the amplifier circuit module, and the number of drain power supply circuits is determined based on the number of drain voltage power supply terminals of the amplifier circuit module. The gate power supply circuit and the drain power supply circuit include a filter network. Each stage of the transistor amplifier circuit sub-module of the amplifier circuit module includes a gate voltage supply terminal and at least one drain voltage supply terminal. All gate voltage supply terminals of the amplifier circuit module are connected to the same gate power supply circuit, or the gate voltage supply terminals of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module are respectively connected to a gate power supply circuit. Each drain voltage supply terminal of each stage of the transistor amplifier circuit sub-module of the amplifier circuit module is connected to a drain power supply circuit. The gate power supply circuit is used to provide the gate voltage, and the drain power supply circuit is used to provide the drain voltage. The gate power supply circuit and the drain power supply circuit together determine the static operating point of each stage transistor amplifier sub-module of the amplifier circuit module, and suppress the signal gain outside the operating frequency band of the amplifier circuit module through the filter network.

3. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 2, characterized in that, The drain power supply circuit includes a first power supply terminal, a drain voltage output terminal, a first filter resistor, a first filter capacitor, a second filter resistor, a second filter capacitor, a first passive microstrip line, a third filter capacitor, and an isolation inductor. The first power supply terminal is used to connect to the first DC voltage source; One end of the first filter resistor is connected to the first power supply terminal, and the other end is connected in series with the first filter capacitor and then grounded to form a first filter network. The second filter resistor, the second filter capacitor and the first passive microstrip line are connected in parallel, with one end connected to the first power supply terminal and the other end connected to the first terminal of the isolation inductor to form a second filter network. The first end of the isolation inductor is grounded through the third filter capacitor, and the second end of the isolation inductor is connected to the drain voltage output terminal. The drain voltage output terminal serves as one of the output ports of the bias filter circuit and is connected to the drain voltage power supply terminal.

4. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 2, characterized in that, The gate power supply circuit includes a second power supply terminal, a gate voltage output terminal, a third filter resistor, a fourth filter resistor, a fourth filter capacitor, a fifth filter capacitor, and a second passive microstrip line. The second power supply terminal is used to connect to the second DC voltage source; One end of the third filter resistor is connected to the second power supply terminal, and the other end is connected in series with the fourth filter capacitor and then grounded to form a third filter network. The fourth filter resistor, the fifth filter capacitor, and the second passive microstrip line are connected in parallel, with one end connected to the second power supply terminal and the other end connected to the gate voltage output terminal to form the fourth filter network. The gate voltage output terminal serves as one of the output ports of the bias filter circuit and is connected to the gate voltage power supply terminal.

5. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 2, characterized in that, The voltages used by the gate power supply circuit and the drain power supply circuit are different.

6. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 1, characterized in that, The first-stage transistor amplifier circuit sub-module of the amplifier circuit module includes an input matching circuit, a first-stage transistor amplifier unit circuit, and a first-stage inter-stage matching circuit. The input matching circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the radio frequency input terminal, and the first output terminal is connected to the input terminal of the first-stage transistor amplifier unit circuit. The input matching circuit is used to match the impedance of the signal source transmitting the radio frequency signal with the input impedance of the first-stage transistor amplifier circuit submodule, and to superimpose a positive slope frequency response curve on the radio frequency signal received by the radio frequency input terminal. The first-stage transistor amplifier unit circuit is used to amplify the radio frequency signal input from the radio frequency input terminal in the first stage. The input terminal of the first-stage matching circuit is connected to the output terminal of the first-stage transistor amplifier unit circuit. The first-stage matching circuit is used to perform impedance matching between the first-stage transistor amplifier unit circuit and the next-stage transistor amplifier circuit submodule of the first-stage transistor amplifier circuit submodule.

7. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 6, characterized in that, The input matching circuit includes a matching inductor, a matching resistor, a first matching capacitor, a second matching capacitor, a third passive microstrip line, and a fourth passive microstrip line. One end of the matching inductor is connected to the radio frequency input terminal, and the other end is grounded; The matching resistor, the first matching capacitor, and the third passive microstrip line are connected in parallel. One end of the parallel connection is connected to the RF input terminal, and the other end is connected in series with the second matching capacitor and the fourth passive microstrip line and then connected to the input terminal of the first stage transistor amplifier unit circuit.

8. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 1, characterized in that, The final stage transistor amplifier circuit sub-module of the amplifier circuit module includes a final stage transistor amplifier unit circuit and an output power coupling circuit. The input terminal of the final stage transistor amplifier unit circuit is connected to the output terminal of the previous stage transistor amplifier circuit submodule of the final stage transistor amplifier circuit submodule. The final stage transistor amplifier unit circuit is used to amplify the signal output by the previous stage transistor amplifier circuit submodule of the final stage transistor amplifier circuit submodule. The output power coupling circuit includes a coupling input terminal and a coupling output terminal. The coupling input terminal is connected to the output terminal of the final stage transistor amplifier unit circuit, and the coupling output terminal is connected to the radio frequency output terminal. The output power coupling circuit is used to convert the load impedance of the back-end load connected to the radio frequency output terminal to match the output impedance of the final stage transistor amplifier unit circuit, and to couple the signal output by the final stage transistor amplifier unit circuit to the radio frequency output terminal.

9. The multi-stage monolithic microwave integrated circuit power amplifier according to claim 1, characterized in that, The intermediate stage transistor amplifier circuit sub-module of the amplifier circuit module includes an intermediate stage transistor amplifier unit circuit and an intermediate stage inter-stage matching circuit. The input terminal of the intermediate stage transistor amplifier unit circuit is connected to the output terminal of the preceding stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule. The intermediate stage transistor amplifier unit circuit is used to amplify the signal output by the preceding stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule. The intermediate stage matching circuit is used to perform impedance matching on the intermediate stage transistor amplifier unit circuit and the next stage transistor amplifier circuit submodule of the intermediate stage transistor amplifier circuit submodule.

10. The multi-stage monolithic microwave integrated circuit power amplifier according to any one of claims 6 to 9, characterized in that, Each transistor amplification unit circuit includes at least one transistor, the number of which is determined based on the target output power of the amplification circuit module.

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