High-efficiency multi-channel gallium nitride power amplifier

Abstract

The invention discloses a high-efficiency multi-channel gallium nitride power amplifier, which comprises a common-stage low-power module, a channel switching module and a high-power high-gain module, and is characterized in that the common-stage low-power module is used for pre-amplifying a radio-frequency signal input from a signal input end of the amplifier to obtain a pre-amplified signal; the path switching module is used for switching a transmission path of the pre-amplified signal, and the transmission path comprises a first path where the high-power high-gain module is located and a second path for directly outputting the pre-amplified signal to the signal output end of the amplifier; the output end of the high-power high-gain module is connected with the signal output end of the amplifier, and the high-power high-gain module is used for amplifying the pre-amplified signal and then outputting the pre-amplified signal from the signal output end of the amplifier. The low-power branch is placed in front of the access switching module to serve as common input, an output switch is omitted, and the influence of insertion loss of the output switch on circuit efficiency can be avoided when signals are output from the high-power high-gain module at high power.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a high-efficiency multi-channel gallium nitride power amplifier. Background Art

[0002] Gallium nitride (GaN) semiconductor power devices are often used in satellite communications, radar and other equipment due to their high temperature, high power and radiation resistance. In order to adapt to different power scenarios, existing GaN power amplifiers generally have high-power high-gain paths and low-power low-gain paths. The two ends of the high-power high-gain paths and low-power low-gain paths are connected with input switches and output switches. The input switches and output switches are used to switch the input signal to the high-power high-gain path or the low-power low-gain path for amplification and output according to the signal application scenario.

[0003] like Figure 1-Figure 2 As shown, the input switch includes switch 1 and switch 2, and the output switch includes switch 3 and switch 4. When switch 1 and switch 2 are closed and switch 3 and switch 4 are disconnected, the input signal is amplified and output through the high-power high-gain path, and the low-power low-gain path does not work at this time. Similarly, when switch 3 and switch 4 are closed and switch 1 and switch 2 are disconnected, the input signal is amplified and output through the low-power low-gain path, and the high-power high-gain path does not work at this time. Among them, both the input and output switches will introduce insertion loss, which will cause the power of the power amplifier to be reduced. And when the signal is output from the high-power high-gain path and the high-power amplifier module is working, because there is a high-power signal to pass through, the power resistance of switch 2 has a very large impact on the circuit reliability. The insertion loss of switch 2 has a very obvious impact on the overall efficiency of the circuit when it is output at high power. Therefore, switch 2 is the bottleneck of the amplifier's high-power output capability and efficiency. Summary of the invention

[0004] The object of the present invention is to provide a high-efficiency multi-channel gallium nitride power amplifier. By placing a low-power branch in front of a channel switching module as a front-stage low-power module of a high-power high-gain module and omitting the output switch, the insertion loss of the output switch can be avoided from affecting the circuit efficiency when the signal is output from the high-power high-gain module at high power.

[0005] In order to achieve the above objectives, the following solutions are proposed: The present invention provides a high-efficiency multi-channel gallium nitride power amplifier, comprising a common-level low-power module, a channel switching module, and a high-power high-gain module, wherein: The common low-power module is used to pre-amplify the radio frequency signal input from the amplifier signal input terminal to obtain a pre-amplified signal; The path switching module is used to switch the transmission path of the pre-amplified signal, and the transmission path includes a first path where the high-power high-gain module is located and a second path that directly outputs the pre-amplified signal to the amplifier signal output end. The output end of the high-power high-gain module is connected to the amplifier signal output end, and is used to amplify the pre-amplified signal and then output it.

[0006] In some specific embodiments, the path switching module includes a first input terminal, a first output terminal and a second output terminal, the first input terminal is connected to the output terminal of the common-level low-power module, the first output terminal is connected to the input terminal of the high-power high-gain module, and the second output terminal is connected to the amplifier signal output terminal.

[0007] In some specific embodiments, the path switching module includes a first switching switch and a second switching switch, the first end of the first switching switch and the first end of the second switching switch are connected as the first input end of the path switching module, the second end of the first switching switch serves as the first output end of the path switching module, and the second end of the second switching switch serves as the second output end of the path switching module.

[0008] In some specific embodiments, the path switching module includes a single-pole double-throw switch, the moving contact of the single-pole double-throw switch serves as the first input end of the path switching module, and the two static contacts of the single-pole double-throw switch serve as the first output end and the second output end of the path switching module respectively.

[0009] In some specific implementations, the common-stage low-power module includes a common-stage input matching network, a common-stage amplifier, and a common-stage output matching network connected in series, and the output end of the common-stage output matching network is connected to the first input end of the path switching module.

[0010] In some specific embodiments, the high-power high-gain module includes a front-stage input matching network, a second amplifier, an inter-stage matching network, a third amplifier and an output matching network connected in series in sequence, the input end of the front-stage input matching network is connected to the first output end of the path switching module, and the output end of the output matching network is connected to the circuit amplifier signal output end.

[0011] In some specific implementations, the amplifier signal input terminal is connected to the input terminal of the common input matching network through a first capacitor, and the output terminal of the common output matching network is connected to the first input terminal of the path switching module through a second capacitor.

[0012] In some specific implementations, both the first switch and the second switch are single-pole single-throw switches.

[0013] In some specific embodiments, when the first switching switch is closed and the second switching switch is open, the RF signal is input from the amplifier input end, pre-amplified through the common-level low-power module in sequence, input into the high-power high-gain module through the first switching switch, amplified again, and then output from the amplifier output end.

[0014] In some specific implementations, when the first switching switch is open and the second switching switch is closed, the RF signal is input from the amplifier input terminal, pre-amplified by the common-level low-power module in sequence, and then directly output from the amplifier output terminal through the second switching switch.

[0015] The inventive concept of this application is: In order to adapt to different power output scenarios, it is necessary to switch the signal transmission channel according to the power required by the scenario. The input switch and the output switch are generally used to select the corresponding power path to achieve different working mode switching. In this solution, when the signal is output from the high-power and high-gain path, due to the high power to pass through the output switch, the output switch is required to have a high anti-burning power capacity; at the same time, P-0.1 needs to be greater than the power output under this path; and the insertion loss needs to be as small as possible to avoid the reduction of power and efficiency due to the introduced insertion loss.

[0016] In the present application, in order to reduce the insertion loss effect of the output switch when the signal passes through the high-power high-gain module, the output switch is omitted, and the low-power low-gain module is placed before the path switching module as a common stage of the high-power high-gain path (first path) and the low-power low-gain path (second path). The original high-power high-gain module and the low-power low-gain module are connected in parallel at the input end of the amplifier, which is changed to a cascade structure of a low-power low-gain module, a path switching module, and a high-power high-gain module. In this way, the path switching modules in the entire circuit all work at low power, and the power capacity and linearity requirements of the switch are reduced, so that the system works in a more efficient and stable state.

[0017] In addition, since the existing high-power high-gain module contains a multi-stage power amplifier, and the low-power low-gain module can just serve as a pre-amplifier of the high-power high-gain module, the low-power low-gain module is placed before the path switching module as a common-level low-power module connected to the amplifier signal input terminal, and the input signal is pre-amplified so that the signal output can meet both the output requirements of the second path and the input requirements of the first path. In this way, the pre-amplifier of the high-power high-gain module can also be omitted, thereby simplifying the design.

[0018] The present invention has the beneficial effects: The present invention provides a high-efficiency multi-channel gallium nitride power amplifier, in which an output switch at the signal output end of the amplifier is omitted, and a low-power and low-gain module is placed before a channel switching module as a common stage of a first channel and a second channel, so that the channel switching modules in the entire circuit all work at low power, and the power capacity and linearity requirements of the switch are reduced, and the high-frequency insertion loss and isolation indexes of the switch can be more easily improved and designed, so that the system works in a more efficient and stable state.

[0019] In addition, the second switching switch in the path switching module also plays a role of high isolation, reducing the feedback effect from the first path leakage to the second path and back to the low-power and low-gain module, thereby reducing the risk of circuit oscillation caused by power leakage in the first path. When the second switching switch is closed, it can also serve as a RF path to simplify the power supply design. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit diagram of a conventional power amplifier in the prior art when operating at high power amplification; Figure 2 It is a circuit diagram of a conventional power amplifier in the prior art when operating at low power amplification; Figure 3 A schematic diagram of the circuit composition of a high-efficiency multi-channel gallium nitride power amplifier provided in Example 1 of the present invention; Figure 4 A schematic diagram of the circuit composition of a high-efficiency multi-channel gallium nitride power amplifier provided in Example 2 of the present invention; Figure 5 A schematic diagram of the circuit composition of a high-efficiency multi-channel gallium nitride power amplifier provided in Example 3 of the present invention; Figure 6 A comparison diagram of the output power of the present invention and the traditional structure during high-power amplification; Figure 7 A comparison diagram of the additional power provided by the present invention during high-power amplification with that of the traditional structure; Figure 8 A power comparison diagram of the present invention and the traditional structure during low-power amplification. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0023] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0024] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness.One of ordinary skill in the art will recognize that various changes and modifications may be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0025] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0026] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0027] The existing power amplifier includes a high-power high-gain module and a low-power low-gain module connected in parallel with input switches (switch 1 and switch 3) and output switches (switch 2 and switch 4). The function of switching the path is completed by switching the input and output switches. The signal is directly divided into two upper and lower paths from the amplifier signal input end, one of which is used as the output of the high-power high-gain module, and the other is used as the output of the low-power low-gain path. In addition, the high-efficiency high-gain module includes an input matching network, a first-level and second-level matching network, a first-level amplifier, a second-level amplifier, a second-level and third-level matching network, a third-level amplifier, and an output matching network, while the low-power low-gain module includes an input matching network, a first-level amplifier, and an output matching network. It can be seen that the function of the first-level amplifier between the high-power high-gain module and the low-power low-gain module is the same. When working, when only one path is working, the same part of the device is relatively idle.

[0028] like Figure 1 As shown, when the RF signal needs to be amplified at high power, switch 1 is closed to switch to the high power and high gain path, switch 2 is closed to switch the amplifier signal output end to the high power and high gain path, the amplifier of the high power and high gain module works, the RF signal enters the high power and high gain module through switch 1 for amplification and then passes through switch 2 to the amplifier signal output port. At this time, switch 3 and switch 4 are both disconnected, the low power and low gain path is in a closed state, and the circuit only works in the high power amplification mode.

[0029] Likewise, if Figure 2 As shown, when the RF signal needs to be amplified at a low power, switch 3 is closed and switched to the low power and low gain path, switch 4 is closed and switches the amplifier signal output end to the low power and low gain path, the amplifier of the low power and low gain module works, the RF signal enters the low power and low gain module through switch 3 for amplification and then passes through switch 4 to the amplifier signal output port. At this time, switch 1 and switch 2 are both disconnected, the high power and high gain path is in a closed state, and the circuit only works in a low power amplification mode.

[0030] In this way, for switch 2 at the output end of the high-power high-gain module, switch 2 is required to have a high anti-burning power capacity; at the same time, P-0.1 needs to be greater than the power output under this channel; and the insertion loss of the switch needs to be as small as possible to avoid the reduction of power and efficiency due to the introduced insertion loss. Switch 2 is the bottleneck of the high-power output capacity and efficiency of this circuit. In view of this, this application proposes the following solution: Example 1 like Figure 3 As shown, this embodiment provides a high-efficiency multi-channel GaN power amplifier, including a common-level low-power module, a channel switching module, and a high-power high-gain module, wherein: The common-level low-power module is used to pre-amplify the radio frequency signal input from the amplifier signal input terminal RFIN to obtain a pre-amplified signal; the common-level low-power module includes a common-level input matching network, a common-level amplifier, and a common-level output matching network connected in series, and the output end of the common-level output matching network is connected to the first input end of the path switching module. More specifically, the amplifier signal input terminal RFIN is connected to the input end of the common-level input matching network through a first capacitor C1, and the output end of the common-level output matching network is connected to the first input end of the path switching module through a second capacitor C2.

[0031] The path switching module is used to switch the transmission path of the pre-amplified signal, and only one of the transmission paths is turned on each time, and the transmission paths include a first path where the high-power high-gain module is located and a second path that directly outputs the pre-amplified signal to the amplifier signal output end; Specifically, the path switching module includes a first input terminal, a first output terminal and a second output terminal, the first input terminal is connected to the output terminal of the common-level low-power module, the first output terminal is connected to the input terminal of the high-power high-gain module, and the second output terminal is connected to the amplifier signal output terminal RFOUT through capacitor C3.

[0032] The output end of the high-power high-gain module is connected to the amplifier signal output end RFOUT, and is used to amplify the pre-amplified signal and then output it. The high-power high-gain module includes a pre-stage input matching network, a second amplifier, an inter-stage matching network, a third amplifier and an output matching network connected in series in sequence, the input end of the pre-stage input matching network is connected to the first output end of the path switching module, and the output end of the output matching network is connected to the circuit amplifier signal output end RFOUT.

[0033] The working process of the power amplifier is: When the RF signal needs to be amplified at a high power, the path switching module switches to output from the first output terminal, the first path is turned on, and the RF signal is input to the common amplifier through the amplifier signal input terminal RFIN for pre-amplification processing. Then, the pre-amplified signal enters the first path from the first input terminal and the first output terminal, and is directly output from the amplifier signal output terminal RFOUT after being amplified by the second amplifier and the third amplifier in two stages. When the RF signal needs to be amplified at a low power, the path switching module switches to output from the second output terminal, the second path is turned on, and the RF signal is input into the common-level amplifier through the amplifier signal input terminal RFIN for pre-amplification processing. Since the second path is only used as a transmission path and does not amplify the pre-amplified signal, the pre-amplified signal is output directly from the second path from the first input terminal and the second output terminal to the amplifier signal output terminal RFOUT.

[0034] Example 2 like Figure 4 As shown, the difference between this embodiment and embodiment 1 is that the path switching module of this embodiment includes a first switching switch SW1 and a second switching switch SW2. The first switching switch SW1 and the second switching switch SW2 both use single-pole single-throw switches, and the moving contacts of the first switching switch and the second switching switch are used as the first end, and the static contacts are used as the second end. The first end of the first switching switch SW1 and the first end of the second switching switch SW2 are connected as the first input end of the path switching module, the second end of the first switching switch SW1 is used as the first output end of the path switching module, and the second end of the second switching switch SW2 is used as the second output end of the path switching module. And it can be considered that the second switching switch SW2 is set in the second path, so that the second switching switch SW2 plays a role of high isolation, reducing the feedback effect of the signal from the second path back to the public-level low-power module due to power leakage of the first path. At this time, the working process of the power amplifier is: When the RF signal needs to be amplified at high power, the first switching switch SW1 is closed and the second switching switch SW2 is opened. After the RF signal is input from the amplifier input terminal RFIN, it is pre-amplified by the first amplifier of the common-level low-power module in sequence, and then input to the second amplifier and the third amplifier in the high-power high-gain module through the first switching switch SW1 for two-stage amplification again, and then output from the amplifier output terminal RFOUT.

[0035] When the RF signal needs to be amplified at a low power, the first switching switch SW1 is opened and the second switching switch SW2 is closed. The RF signal is input from the amplifier input terminal RFIN, pre-amplified by the common-level low-power module in sequence, and then directly output from the amplifier output terminal RFOUT through the second switching switch SW2.

[0036] Example 3 like Figure 5 As shown, the difference between this embodiment and embodiment 1 is that the path switching module of this embodiment adopts a single-pole double-throw switch SPDT, the moving contact A of the single-pole double-throw switch serves as the first input end of the path switching module, the static contact B of the single-pole double-throw switch serves as the first output end of the path switching module, and the static contact C of the single-pole double-throw switch serves as the second output end of the path switching module.

[0037] At this time, the working process of the power amplifier is: When the RF signal needs to be amplified at a high power, the single-pole double-throw switch SPDT switches on the moving contact A and the static contact B. After the RF signal is input from the amplifier input terminal RFIN, it is pre-amplified by the first amplifier of the common-level low-power module in sequence, and then input to the high-power high-gain module through the single-pole double-throw switch SPDT. The second and third amplifiers perform two-stage amplification again and then output from the amplifier output terminal RFOUT.

[0038] When the RF signal needs to be amplified at a low power, the single-pole double-throw switch SPDT switches on the moving contact A and the static contact C. The RF signal is input from the amplifier input terminal RFIN and then pre-amplified by the common-level low-power module. It is then directly output from the amplifier output terminal RFOUT after passing through the single-pole double-throw switch SPDT.

[0039] It can be understood that, from the above embodiments, the switches in the path switching module in the present application all operate at low power, which reduces the power capacity and linearity requirements of the path switching module, and can more easily improve the design of the switch high-frequency insertion loss and isolation indicators. The circuit operates in a more efficient and stable state. The common-level amplifier pre-amplifies the RF signal so that the signal output meets both the output requirements of the second channel and the input requirements of the first channel. And the number of amplifier stages in the first channel is reduced, simplifying the design.

[0040] like Figure 6-Figure 7 As shown, according to the structure in the above embodiment, a performance comparison diagram of the power amplifier designed by the present application and the traditional power amplifier can be obtained, as shown in FIG. Figure 6 As shown, when the power amplifier performs high-power amplification on the radio frequency signal, the peak output power and additional power of the structure of the present invention are improved at a frequency of 8-12 GHz. Figure 8 As shown, when the radio frequency signal is amplified at a low power, the peak output power of the present invention remains almost unchanged. The performance comparison between the structure of the present invention and the existing structure under different working modes is shown in Table 1: Table 1 Performance comparison table Therefore, it can be seen that compared with the existing structure, the present application not only omits switch 2 and switch 4, reducing the switching loss when the power amplifier works in the high-power amplification mode and improving the power of the amplifier, but also can multiplex the amplifier and simplify the circuit design.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A high-efficiency multi-channel gallium nitride power amplifier, characterized in that: It includes a public-level low-power module, a path switching module, and a high-power high-gain module, among which: The common low-power module is used to pre-amplify the radio frequency signal input from the amplifier signal input terminal to obtain a pre-amplified signal; The path switching module is used to switch the transmission path of the pre-amplified signal, and the transmission path includes a first path where the high-power high-gain module is located and a second path that directly outputs the pre-amplified signal to the amplifier signal output end; The output end of the high-power high-gain module is connected to the amplifier signal output end, and is used to amplify the pre-amplified signal and output it from the amplifier signal output end.

2. The high-efficiency multi-channel gallium nitride power amplifier according to claim 1, characterized in that: The path switching module includes a first input terminal, a first output terminal and a second output terminal. The first input terminal is connected to the output terminal of the common low-power module, the first output terminal is connected to the input terminal of the high-power high-gain module, and the second output terminal is connected to the amplifier signal output terminal.

3. The high-efficiency multi-channel gallium nitride power amplifier according to claim 2, characterized in that: The path switching module includes a first switching switch and a second switching switch. The first end of the first switching switch and the first end of the second switching switch are connected as the first input end of the path switching module, the second end of the first switching switch serves as the first output end of the path switching module, and the second end of the second switching switch serves as the second output end of the path switching module.

4. The high-efficiency multi-channel gallium nitride power amplifier according to claim 2, characterized in that: The path switching module includes a single-pole double-throw switch, the moving contact of the single-pole double-throw switch serves as the first input end of the path switching module, and the two static contacts of the single-pole double-throw switch serve as the first output end and the second output end of the path switching module respectively.

5. The high-efficiency multi-channel gallium nitride power amplifier according to claim 2, characterized in that: The common-level low-power module comprises a common-level input matching network, a common-level amplifier and a common-level output matching network which are connected in series in sequence, and the output end of the common-level output matching network is connected to the first input end of the path switching module.

6. The high-efficiency multi-channel gallium nitride power amplifier according to claim 2, characterized in that: The high-power high-gain module includes a front-stage input matching network, a second amplifier, an inter-stage matching network, a third amplifier and an output matching network which are connected in series in sequence. The input end of the front-stage input matching network is connected to the first output end of the path switching module, and the output end of the output matching network is connected to the circuit amplifier signal output end.

7. The high-efficiency multi-channel gallium nitride power amplifier according to claim 3, characterized in that: The first switch and the second switch are both single-pole single-throw switches.

8. The high-efficiency multi-channel gallium nitride power amplifier according to claim 7, characterized in that: When the first switching switch is closed and the second switching switch is open, the RF signal is input from the amplifier input end, pre-amplified through the common-level low-power module in sequence, input into the high-power high-gain module through the first switching switch, amplified again, and then output from the amplifier output end.

9. The high-efficiency multi-channel gallium nitride power amplifier according to claim 7, characterized in that: When the first switch is open and the second switch is closed, the RF signal is input from the amplifier input terminal, pre-amplified by the common-level low-power module in sequence, and then directly output from the amplifier output terminal through the second switch.

Images