Ka-band high-linearity power amplifier

Abstract

The invention belongs to the technical field of satellite communication, and particularly relates to a Ka-band high-linearity power amplifier, which comprises a radio frequency shell, a radio frequency circuit, a power supply circuit, a control circuit and a radio frequency connector, and is characterized in that an input main channel circuit of the radio frequency circuit comprises an attenuator I, an equalizer, a temperature compensation circuit and an amplitude-phase control chip which are connected in sequence; a circuit is divided into multiple paths of shunt circuits through an amplitude-phase control chip, each path of shunt circuit comprises an attenuator II, a driving amplification chip, an isolator I, a final-stage power amplifier chip and a microstrip-to-waveguide structure which are connected in sequence, and the output end of each path of shunt circuit is connected with a power combiner. And the power combiner comprises a waveguide isolator, a waveguide combiner, a filter, a coupler and an isolator which are connected in sequence, wherein the waveguide isolator is used for being connected with each branch circuit, and the waveguide combiner is used for combining each signal. The problem of phase consistency of the power amplifier circuit during multi-channel power synthesis is solved, and the multi-channel power synthesis efficiency and the linearity of the whole power amplifier are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communication, and particularly relates to a Ka-band high-linear power amplifier. Background Art

[0002] With the rapid development of satellite communication technology, the requirements for channel quality are constantly increasing. High power and high linearity have gradually become important indicators in satellite communication. The high-power Ka-band transmission technology applicable to satellite communication has attracted increasing attention in the industry. In order to improve the channel capacity and communication quality of satellite communication, achieving high-power output and high-linear amplification of the power amplifier has become the main research content of the power amplifier. To solve the technical difficulties of high-power and high-linear technology for satellite communication, the multi-channel combined power amplifier technology has become the main research direction. However, due to the low efficiency of multi-channel power combination, it is difficult to improve the linearity of high-power power amplifiers. To solve this technical difficulty, a Ka-band high-linear power amplification technology needs to be developed.

[0003] In the prior art, the Ka-band power amplifier technology mainly has three major directions: one is a single-chip amplifier circuit, whose performance mainly depends on the capabilities of the single chip and the matching circuit. The power amplification ability is limited and the linearity is not high; second, the power combination technology is adopted, in which multiple power amplifier circuits are combined, and the power combination is realized by using the principle of in-phase power superposition. However, the synthesis efficiency of this technology is not high and the power linearity is not high; third, in order to improve the linearity of the combined power, a predistortion feedback circuit is added to the microwave drive circuit, and the output linearity of the power amplifier is continuously adjusted through the circuit self-feedback, thereby improving the output linearity of the power amplifier. However, this scheme has a complex circuit, a large size, poor reliability, and a high cost, and cannot be applied in large-scale engineering.

[0004] The disadvantages of the prior art are summarized as follows: (1) The single-chip power amplification technology is limited by the performance of the single chip and the matching of the microwave circuit. The power amplification ability is limited and the linearity control is unstable; (2) The multi-channel combination technology currently has low synthesis efficiency, resulting in low output power and linearity of the power amplifier, which affects large-scale engineering use; (3) The predistortion processing technology has a complex circuit, high circuit control requirements, a large product size, and a high development cost, which restricts its large-scale application in engineering. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a Ka-band high-linear power amplifier.

[0006] The object of the present invention is achieved by the following technical solutions. A Ka-band high-linearity power amplifier proposed according to the present invention includes a radio frequency housing, a radio frequency circuit disposed within the radio frequency housing, a power supply circuit and a control circuit disposed outside the radio frequency housing and connected to the radio frequency circuit, and a radio frequency connector for connecting to the radio frequency circuit and the outside of the radio frequency housing. The input main channel circuit of the radio frequency circuit includes an attenuator I, an equalizer, a temperature compensation circuit, and a amplitude-phase control chip connected in sequence. After passing through the amplitude-phase control chip, the circuit is divided into multiple branch circuits. Each branch circuit includes an attenuator II, a drive amplifier chip, an isolator I, a final power amplifier chip, and a microstrip-to-waveguide structure connected in sequence. The output ends of each branch circuit are connected to a power combiner. The power combiner includes a waveguide isolator for connecting to each branch circuit respectively, a waveguide combiner for combining each signal, a filter, a coupler, and an isolator connected in sequence.

[0007] Further, the radio frequency housing is made of copper, and the surface of the radio frequency housing is processed by a silver plating process with a plating thickness of 3 - 4 μm. The outside of the radio frequency housing is also coated with a plating protection liquid.

[0008] Further, the cavity height of the radio frequency housing is 2.8 mm, and the cavity width is 3 mm.

[0009] Further, the coupler is connected to a sampling circuit. The sampling circuit includes an attenuation and equalization circuit, a detector, and an AD chip connected in sequence.

[0010] Further, the amplitude-phase control chip is independently packaged using a microwave multilayer board structure and is encapsulated within the cavity of this structure.

[0011] Further, the radio frequency circuit is powered by +26V, and the power supply circuit and the control circuit are interconnected with the radio frequency circuit within the radio frequency housing through a flexible pin connector.

[0012] Further, the final power amplifier chip is a bare chip made of GaN with a saturation output power of 20W, and diamond material is used as the carrier of the final power amplifier chip.

[0013] Further, the thickness of the carrier is 0.8 mm.

[0014] Further, the power supply circuits of every two final power amplifier chips use a group of current-limiting inductance coils to filter the drain voltage.

[0015] Further, the amplitude-phase control chip divides the circuit into 8 branch circuits.

[0016] Compared with the prior art, the advantages of the present invention are as follows:

[0017] The present invention combines phased array technology with power amplifier synthesis technology, which well solves the problem of phase consistency in multi-channel power synthesis of the power amplifier circuit, and greatly improves the multi-channel power synthesis efficiency and the linearity of the overall power amplifier.

[0018] The problems solved by the present invention are summarized as follows:

[0019] (1) Solve the problem of high-power amplification for satellite communication (for Ka-band continuous wave, it can achieve a saturated output power of not less than 100W and has the ability to expand power according to the required output power).

[0020] (2) Solve the problem of amplitude-phase consistency in multi-channel power synthesis.

[0021] (3) Solve the problem of high linearity of the high-power continuous wave output signal of the power amplifier.

[0022] (4) Use software control (implemented through the control circuit) to improve the efficiency of amplitude-phase debugging in multi-channel power synthesis and solve the problem of improving the efficiency of large-scale engineering production.

[0023] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically given and described in detail in conjunction with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the RF circuit in an embodiment of a Ka-band high-linearity power amplifier of the present invention.

[0025]

REFERENCE SIGNS

[0026] 1 - Attenuator I;

[0027] 2 - Equalizer;

[0028] 3 - Temperature compensation circuit;

[0029] 4 - Amplitude-phase control chip;

[0030] 5 - Attenuator II;

[0031] 6 - Driver amplification chip;

[0032] 7 - Isolator I;

[0033] 8 - Final power amplifier chip;

[0034] 9 - Microstrip-to-waveguide structure;

[0035] 10 - Waveguide combiner;

[0036] 11 - Waveguide isolator;

[0037] 12 - Filter;

[0038] 13 - Coupler;

[0039] 14 - Isolator II;

[0040] 15 - Attenuation equalization circuit;

[0041] 16 - Detector;

[0042] 17 - AD chip. Detailed implementation manners

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some but not all of the embodiments of this application. Usually, the components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application.

[0045] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0046] In the description of this application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0047] In addition, the terms "horizontal", "vertical", "overhanging", etc. do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0048] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication between two components inside. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0049] In the present application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0050] The features and performance of a Ka-band high-linearity power amplifier suitable for the present application will be further described in detail below in conjunction with embodiments.

[0051] Embodiment 1 of a Ka-band high-linearity power amplifier of the present invention includes a radio frequency housing, a radio frequency circuit, a power supply circuit, a control circuit, and a radio frequency connector.

[0052] The radio frequency circuit is arranged inside the radio frequency housing, and the radio frequency circuit is communicatively connected to the outside of the radio frequency housing through the radio frequency connector.

[0053] The radio frequency signal is input into the radio frequency circuit through the corresponding radio frequency connector, and the power-amplified signal is output through the corresponding waveguide port.

[0054] The radio frequency housing is made of copper, and the surface of the radio frequency housing is processed by a silver plating process with a plating thickness of 3 - 4 μm. A plating protection liquid is also coated on the outside of the radio frequency housing to ensure that the plating is not oxidized.

[0055] The cavity height of the radio frequency housing is designed to be 2.8 mm, and the cavity width is 3 mm, which is suitable for Ka-band signal transmission and avoids the occurrence of cavity self-excitation effect.

[0056] The radio frequency circuit includes an attenuator, an equalizer 2, a temperature compensation circuit 3, an amplitude-phase control chip 4, a driver amplifier chip 6, an isolator, a final power amplifier chip 8, a microstrip-to-waveguide structure 9, a waveguide combiner 10, and a sampling circuit, as Figure 1 shown.

[0057] The waveguide synthesizer 10 integrally incorporates a waveguide isolator 11, an 8-in-1 waveguide combiner, a filter 12, and a coupler 13.

[0058] The sampling circuit is connected to the coupler 13 and includes an attenuation and equalization circuit 15, a detector 16, and an AD chip (analog-to-digital converter) 17 connected in sequence.

[0059] The input main channel circuit of the RF circuit includes an attenuator I 1, an equalizer 2, a temperature compensation circuit 3, and a magnitude and phase control chip 4 connected in sequence.

[0060] Each branch circuit of the RF circuit includes an attenuator II 5, a driver amplifier chip 6, an isolator I 7, a final power amplifier chip 8, and a microstrip-to-waveguide structure 9 connected in sequence.

[0061] The RF signal sequentially passes through the attenuator I 1, the equalizer 2, the temperature compensation circuit 3, and the magnitude and phase control chip 4 of the input main channel circuit of the RF circuit. The magnitude and phase control chip 4 divides the RF signal into 8 paths and controls the amplitude and phase of each path of the RF signal.

[0062] The magnitude and phase control chip 8 is used to implement magnitude and phase regulation of the 8-way power amplifier synthesis circuit ( Figure 1 the shown RF circuit), improving the synthesis efficiency of the 8-way power amplifier synthesis circuit.

[0063] Each path of the RF signal sequentially passes through the attenuator II 5, the driver amplifier chip 6, the isolator I 7, the final power amplifier chip 8, and the microstrip-to-waveguide structure 9 in the corresponding branch circuit. Each path of the signal is amplified twice (respectively realized by the driver amplifier chip 6 and the final power amplifier chip 8) and is transmitted to the power synthesizer 10 after being converted by the microstrip-to-waveguide structure 9.

[0064] In the power synthesizer 10, a waveguide isolator 11 is first set for each path of the signal, and then each path of the signal is combined through an 8-in-1 waveguide combiner, and then output through the filter 12 and the coupler 13. An isolator II 14 is set at the output end.

[0065] The coupler 13 is connected to the sampling circuit, and the output signal is sampled through the sampling circuit. In the sampling circuit, the output signal sequentially passes through the attenuation and equalization circuit 15, the detector 16, and the AD chip 17.

[0066] The power synthesizer 10 is provided with a waveguide isolator 11 on each branch circuit, and the waveguide isolator 11 is no longer set at the synthesis common end of the power synthesizer 10.

[0067] The amplitude-phase control chip 4 is independently packaged using a microwave multilayer board structure and is encapsulated within the cavity of this structure, serving as the common terminal of this power amplifier circuit (radio frequency circuit). The amplitude-phase control chip 4 controls the phase and amplitude of eight radio frequency channels (8-way shunt circuits) through the SPI bus.

[0068] The radio frequency circuit is powered by +26V. The power supply circuit and the control circuit are interconnected with the radio frequency circuit within the radio frequency housing through a flexible pin connector, facilitating power supply to the radio frequency circuit and facilitating the debugging and assembly of the power amplifier module (including the drive amplifier chip 6 and the final stage power amplifier chip 8).

[0069] Using the flexible pin connector, it is possible to achieve solderless power supply interconnection between the power supply board (or power control board, on which the power supply circuit is provided) and the radio frequency circuit, and achieve solderless control interconnection between the control circuit board (on which the control circuit is provided) and the radio frequency circuit.

[0070] The final stage power amplifier chip 8 uses a GaN material die with a saturated output power of 20W, and uses diamond material as the carrier of the final stage power amplifier chip, with a carrier thickness of 0.8mm.

[0071] The power supply circuit of the 8-way final stage power amplifier chip 8 uses 4 groups of current-limiting inductance coils (5mH) to filter the drain voltage, and connects the drains of every two final stage power amplifier chips 8 to the corresponding power supply through the same corresponding inductance coil.

[0072] The present invention combines phased array technology and power amplifier synthesis technology, and well solves the problem of phase consistency in multi-channel power synthesis of the power amplifier circuit, greatly improving the multi-channel power synthesis efficiency and the linearity of the overall power amplifier.

[0073] The problems solved by the present invention are summarized as follows:

[0074] (1) Solve the problem of high-power amplification for satellite communication (for Ka-band continuous wave, it can achieve a saturated output power of not less than 100W and has the ability to expand power according to the required output power).

[0075] (2) Solve the problem of amplitude-phase consistency in multi-channel power synthesis.

[0076] (3) Solve the problem of high linearity of the high-power continuous wave output signal of the power amplifier.

[0077] (4) Use software control (implemented through the control circuit) to improve the efficiency of amplitude-phase debugging in multi-channel power synthesis and solve the problem of improving the efficiency of large-scale engineering production.

[0078] In the second embodiment of a Ka-band high linearity power amplifier of the present invention, based on the first embodiment, the number of branch circuits can be changed according to the need for power amplification.

[0079] Embodiment 3 of a Ka-band high-linearity power amplifier according to the present invention. On the basis of Embodiment 1, the power supply circuit and the control circuit can be arranged outside the RF housing and nested within the housing of the RF housing.

[0080] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A Ka-band high linearity power amplifier, characterized in that: The invention comprises a radio frequency shell, a radio frequency circuit arranged in the radio frequency shell, a power supply circuit and a control circuit arranged outside the radio frequency shell and connected to the radio frequency circuit, and a radio frequency connector used to connect to the radio frequency circuit and the outside of the radio frequency shell. The input main channel circuit of the radio frequency circuit comprises an attenuator I, an equalizer, a temperature compensation circuit, and an amplitude and phase control chip connected in sequence. The circuit is divided into multiple branch circuits through the amplitude and phase control chip. Each branch circuit comprises an attenuator II, a driving amplifier chip, an isolator I, a final power amplifier chip, and a microstrip-to-waveguide structure connected in sequence. The output end of each branch circuit is connected to a power synthesizer. The power synthesizer comprises a waveguide isolator connected in sequence for being respectively connected to each branch circuit, a waveguide combiner for merging each signal, a filter, a coupler, and an isolator.

2. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The radio frequency shell is made of copper, the surface of the radio frequency shell is treated by a silver plating process, the plating thickness is 3-4umm, and the outside of the radio frequency shell is also coated with a plating protection liquid.

3. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The cavity height of the radio frequency housing is 2.8 mm, and the cavity width is 3 mm.

4. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The coupler is connected to a sampling circuit, and the sampling circuit includes an attenuation equalization circuit, a detector, and an AD chip connected in sequence.

5. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The amplitude and phase control chip is independently packaged using a microwave multilayer board structure and is packaged in a cavity of the structure.

6. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The radio frequency circuit is powered by +26V, and the power supply circuit and the control circuit are interconnected with the radio frequency circuit in the radio frequency housing through a flexible pin connector.

7. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The final-stage power amplifier chip adopts a GaN bare chip with a saturated output power of 20W, and diamond material is used as a carrier of the final-stage power amplifier chip.

8. The Ka-band high linearity power amplifier according to claim 7, characterized in that: The carrier has a thickness of 0.8 mm.

9. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The power supply circuit of each two final-stage power amplifier chips uses a set of rated current inductor coils to filter the drain voltage.

10. The Ka-band high linearity power amplifier according to claim 1, characterized in that: The amplitude and phase control chip divides the circuit into 8 branch circuits.

Images