All-solid-state X-waveband transmitter based on GaN field effect transistor

Abstract

The invention discloses an all-solid-state X-waveband transmitter based on a GaN field effect transistor, and belongs to the technical field of microwave measurement. Comprising a power amplification chain unit, a control and signal detection unit and a fan unit, wherein the input end of the power amplification chain unit is connected with a radio frequency input signal, the output end of the power amplification chain unit outputs a radio frequency output signal, and the input end of the control and signal detection unit is connected with a door pocket differential signal, an external communication signal and a local control signal. The output end of the control and signal detection unit outputs a transmitter working state signal, a fault signal and an analog quantity parameter; the power amplification chain unit and the control and signal detection unit are in bidirectional communication connection, and the fan unit provides air quantity required by heat dissipation of the transmitter. The transmitter adopts a multi-stage amplification synthesis mode and a modular compact design, realizes specific power output in a limited space, and achieves modularization and miniaturization.

Description

Technical Field

[0001] The present invention relates to the field of microwave measurement technology, and in particular to an all-solid-state X-band transmitter based on a GaN field-effect transistor. Background Art

[0002] In recent years, X-band weather radar has been increasingly used for meteorological observation in a variety of applications. Currently, X-band microwave power devices include klystrons, magnetrons, and solid-state microwave power tubes. Compared to klystron and magnetron transmitters, solid-state microwave power tubes offer advantages such as lower operating voltage, higher reliability, improved maintainability, lower lifecycle costs, greater maneuverability, and improved fault tolerance.

[0003] Currently, all-solid-state radar transmitters have gradually become dominant, but at high-end frequencies, high-power transmitters are still dominated by vacuum tube transmitters. Traditional high-power vacuum tube transmitters are bulky, inefficient, and have complex circuit structures. In addition to their large size, high current dissipation, and limited functionality, they struggle to meet overall system requirements. Summary of the Invention

[0004] The present invention aims to provide an all-solid-state X-band transmitter based on GaN field-effect transistors, aiming to address at least one of the technical problems existing in the above-mentioned prior art. To achieve this objective, the present invention employs the following technical solutions:

[0005] A fully solid-state X-band transmitter based on GaN field-effect transistors comprises a power amplifier chain unit, a control and signal detection unit, and a fan unit. The power amplifier chain unit input receives a radio frequency input signal, and the power amplifier chain unit outputs a radio frequency output signal. The control and signal detection unit input receives a door frame differential signal, an external communication signal, and a local control signal, and the control and signal detection unit outputs a transmitter operating status signal, a fault signal, and analog parameters. The power amplifier chain unit and the control and signal detection unit are connected for bidirectional communication. The fan unit provides the air volume required for transmitter heat dissipation.

[0006] As a further solution of the present invention: the power amplifier chain unit includes a first-stage 300W power amplifier, a first isolator, a one-to-four power splitter, a second isolator, a second-stage 300W power amplifier, a third isolator, a four-in-one power combiner and a waveguide coupler; wherein the input end of the first-stage 300W power amplifier is connected to the RF input signal, and the output end of the first-stage 300W power amplifier is connected to the input end of the first isolator; the output end of the first isolator is connected to the input end of the one-to-four power splitter, the output end of the one-to-four power splitter is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the second-stage 300W power amplifier, the output end of the second-stage 300W power amplifier is connected to the input end of the third isolator, the output end of the third isolator is connected to the input end of the four-in-one power combiner, the output end of the four-in-one power combiner is connected to the input end of the waveguide coupler, the output end of the waveguide coupler outputs the RF output signal, and the coupling end of the waveguide coupler is connected to the input end of the control and signal detection unit.

[0007] As a further solution of the present invention: the control and signal detection unit includes a BITE control circuit, a first-level power amplifier modulation circuit, a second-level power amplifier modulation circuit and a detection circuit; the input end of the BITE control circuit is respectively connected to the door frame differential signal, the external communication signal and the local control signal, and the output end of the BITE control circuit is respectively connected to the first-level power amplifier modulation circuit and the second-level power amplifier modulation circuit; the output end of the first-level power amplifier modulation circuit is connected to the first-level 300W power amplifier; the output end of the second-level power amplifier modulation circuit is connected to the second-level 300W power amplifier, the input end of the detection circuit is connected to the waveguide coupler, and the output end of the detection circuit outputs the detection signal to the BITE control circuit.

[0008] As a further solution of the present invention: the first-stage 300W power amplifier and the second-stage 300W power amplifier both include a GaN field-effect transistor, the source of the field-effect transistor is grounded, the gate of the GaN field-effect transistor is connected to a first capacitor and a first resistor, the other end of the first capacitor is connected to the RF input signal, the other end of the first resistor is connected in parallel to the second resistor, the third capacitor and one end of the fourth capacitor, the other end of the second resistor is connected in series to the fifth capacitor, and the other ends of the third capacitor, the fourth capacitor and the fifth capacitor are grounded; the drain of the GaN field-effect transistor is connected to the second capacitor and the third resistor, the sixth capacitor, the seventh capacitor and the fourth resistor connected in parallel, the other end of the second capacitor is connected to the input end of the first isolator, the other end of the third resistor is connected in series to the eighth capacitor, and the other ends of the sixth capacitor, the seventh capacitor, the eighth capacitor and the fourth resistor are grounded.

[0009] As a further solution of the present invention: the number of the second isolator, the second-stage 300W power amplifier, and the third-stage isolator are all four.

[0010] As a further solution of the present invention: the frequency range of the one-to-four power divider and the four-in-one power combiner is 9.3-9.5GHz, the insertion loss is 0.5dB, the isolation is greater than 20dB, the port standing wave is less than 1.3, the amplitude imbalance is ±0.5dB, the phase imbalance is ±3°, and the withstand power value is 2000W.

[0011] As a further solution of the present invention: the fan unit includes six DC fans.

[0012] Compared with traditional vacuum tube radar, the present invention has the following advantages:

[0013] (1) The present invention includes a power amplification chain unit, a control and signal detection unit, and a fan unit; the present invention adopts a modular design, each working module is relatively independent, easy to disassemble and assemble, and achieves a specific power output in a limited space, achieving modularity and miniaturization. The entire volume of the present invention is much smaller than that of a vacuum tube radar transmitter, and the entire transmitter can be installed on the antenna turntable, which can shorten the waveguide distance between the transmitter and the feeder, reduce power leakage and loss, and help improve the detection performance of the radar equipment;

[0014] (2) The present invention includes a power amplifier chain unit, wherein the first-stage 300W power amplifier and the second-stage 300W power amplifier in the power amplifier chain unit both include GaN field-effect transistors. The GaN field-effect transistors are WCN085096-P55 produced by China Electronics 55 Institute, with an operating frequency range of 9.3-9.5 GHz. The performance of the transistors is stable, thereby increasing the service life of the entire radar equipment and saving maintenance costs.

[0015] (3) The present invention also includes a control and signal detection unit, which includes a BITE control circuit, a first-level power amplifier modulation circuit, a second-level power amplifier modulation circuit, and a detection circuit. Therefore, the present invention can perform real-time detection and analysis on voltage, current, temperature, output RF power, and door frame differential signals, output real-time sampling values ​​of voltage, current, and RF output power, output under-output fault signals when the RF output power is low, and output fault signals when over-duty cycle, over-pulse width, over-temperature, and over-current faults occur, and immediately cut off the timing signals of the first-level power amplifier modulation circuit and the second-level power amplifier modulation circuit, and timely shut down the modulation voltage of the field effect transistor drain, to achieve self-protection function. Therefore, the present invention has a simple structure and stable performance;

[0016] (4) The working voltage of the present invention is low. The working voltages of the transmitter are +40V, +28V, and +12V, among which +40V is the working voltage of the GaN field effect transistor, +28V is the working voltage of the control and signal detection unit, and +12V is the working voltage of the fan component. The voltage value is much lower than the working voltage of the vacuum tube (generally at the level of 10,000 volts), which greatly improves safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of a GaN field-effect transistor-based all-solid-state X-band transmitter according to the present invention;

[0019] Figure 2 It is a schematic diagram of the principle of a first-stage 300W power amplifier and a second-stage 300W power amplifier of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] See also Figure 1 As shown, the present invention is an all-solid-state X-band transmitter based on GaN field-effect transistors, comprising a power amplifier chain unit A0, a control and signal detection unit B0, and a fan unit C0. The input of the power amplifier chain unit A0 receives an RF input signal, and the output of the power amplifier chain unit A0 outputs an RF output signal. The input of the control and signal detection unit B0 receives a door frame differential signal, an external communication signal, and a local control signal, while the output of the control and signal detection unit B0 outputs a transmitter operating status signal, a fault signal, and analog parameters. A bidirectional communication connection is established between the power amplifier chain unit A0 and the control and signal detection unit B0. The fan unit C0 provides the air volume required for transmitter heat dissipation.

[0022] like Figure 1As shown, in a specific embodiment, the power amplifier chain unit includes a first-stage 300W power amplifier A1, a first isolator A2, a one-to-four power distributor A3, a second isolator A4, a second-stage 300W power amplifier A5, a third isolator A6, a four-in-one power combiner A7, and a waveguide coupler A8. Among them, the input end of the first-level 300W power amplifier A1 is connected to the RF input signal, the output end of the first-level 300W power amplifier A1 is connected to the input end of the first isolator A2, the output end of the first isolator A2 is connected to the one-to-four power distributor A3, the four output ends of the one-to-four power distributor A3 are respectively connected to the input ends of four second isolators A4, the output ends of the four second isolators are respectively connected to the input ends of four second-level 300W power amplifiers A5, the output ends of the four second-level 300W power amplifiers are respectively connected to the input ends of four third isolators A6, the output ends of the four third isolators are respectively connected to the four input ends of the four-in-one power combiner A7, the output end of the four-in-one power combiner A7 is connected to the input end of the waveguide coupler A8, the output end of the waveguide coupler A8 outputs the RF output signal, and the coupling end of the waveguide coupler A8 is connected to the input end of the control and signal detection unit B0.

[0023] Preferably, the frequency range of the one-to-four power divider A3 and the four-in-one power combiner A7 is 9.3-9.5GHz, the insertion loss is 0.5dB, the isolation is greater than 20dB, the port standing wave is less than 1.3, the amplitude imbalance is ±0.5dB, the phase imbalance is ±3°, and the withstand power value is 2000W.

[0024] The first isolator A2, the second isolator A4, and the third isolator A6 are all TBG102K4-9400 models produced by Nanjing Tuobang Company. During installation, indium foil is padded on the bottom and input and output sides. The bottom padding is used to ensure better contact between the isolator and the casing, and the side padding is used to fill the assembly gap to prevent changes in the dielectric constant and increase in transmission line loss, thereby reducing attenuation in microwave signal transmission.

[0025] The model of the waveguide coupler A8 is HD-100WL+C40NPEC produced by Xi'an Hengda Microwave Technology Development Co., Ltd., and its coupling degree is 40dB.

[0026] like Figure 1As shown, in one specific embodiment, the control and signal detection unit B0 includes a BITE control circuit B1, a first-level power amplifier modulation circuit B2, a second-level power amplifier modulation circuit B3, and a detection circuit B4. The four input terminals of the BITE control circuit B1 are respectively connected to the door frame differential signal, the communication signal, the local control signal, and the detection signal. The two output terminals of the BITE control circuit B1 are respectively connected to the first-level power amplifier modulation circuit B2 and the second-level power amplifier modulation circuit B3. The output terminal of the first-level power amplifier modulation circuit B2 is connected to the first-level 300W power amplifier A1; the output terminal of the second-level power amplifier modulation circuit B3 is connected to the second-level 300W power amplifier A5. The input terminal of the detection circuit B4 is connected to the waveguide coupler A8, and the output terminal of the detection circuit B4 outputs the detection signal and connects it to the BITE control circuit B1.

[0027] like Figure 1 As shown, in a specific embodiment, the fan unit C0 includes six DC fans C1-C6, model SD120428BU produced by Shengjiu Fan.

[0028] It is worth noting that the circuit structure of the secondary 300W power amplifier A5 is the same as that of the primary 300W power amplifier A1. Figure 2 As shown, the first-stage 300W power amplifier A1 and the second-stage 300W power amplifier A5 both include a GaN field-effect transistor V1, capacitors C1-C8, and resistors R1-R4. The gate of the GaN field-effect transistor V1 is connected to the first capacitor C1 and the first resistor R1. The other end of the first capacitor C1 is connected to the RF input signal. The other end of the first resistor R1 is connected to the second resistor R2, the third capacitor C3, one end of the fourth capacitor C4, and the power supply. The other end of the second resistor R2 is connected to the fifth capacitor C5. The other ends of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are grounded. The drain of the GaN field-effect transistor V1 is connected to the second capacitor C2, the sixth capacitor C6, the seventh capacitor C7, the third resistor R3, the fourth resistor R4, and the power supply. The other end of the second capacitor C2 is connected to the input end of the first isolator A2. The other end of the third resistor R3 is connected to the eighth capacitor C8. The other ends of the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, and the fourth resistor R4 are grounded. The source of the GaN field-effect transistor V1 is grounded.

[0029] Preferably, the model of the GaN field effect transistor V1 is WCN085096-P55 produced by CEC 55, and an indium foil is placed on the bottom during installation to allow the source to better contact the base plate, thereby improving grounding and heat dissipation.

[0030] The base plates of the first-stage 300W power amplifier A1 and the second-stage 300W power amplifier A5 are both made of copper and gold-plated, and the outer surfaces are coated with silicone grease for heat conduction, which is conducive to the heat dissipation of the transmitter, so that the present invention achieves better heat dissipation effect.

[0031] Working principle of the present invention:

[0032] An RF input signal with a peak power of approximately 50W is amplified by a first-stage 300W power amplifier A1 and then fed into the input of the first isolator A2. The output of isolator A2 is connected to the input of a one-to-four power divider A3. During debugging, the connecting cables can be disconnected, and an attenuator and power meter can be connected to measure the peak power at the output of the first isolator A2. If the peak power value is small or has large fluctuations within the band, a matching block can be used to adjust the signal on the first-stage 300W power amplifier A1. Ultimately, the peak power can be adjusted to approximately 300W, with the fluctuations within the band controlled within 1dB. The four output ends of the one-to-four power distributor A3 are connected to the input ends of the four second isolators A4 respectively, the output ends of the four second isolators A4 are connected to the input ends of the four-way two-stage 300W power amplifier A5 respectively, the output ends of the four-way two-stage 300W power amplifier A5 are connected to the input ends of the four third isolators A6 respectively, the output ends of the four third isolators A6 are connected to the four input ends of the four-in-one power combiner A7, the RF output signal output by the output end of the four-in-one power combiner A7 is the combined power of the four-way two-stage 300W power amplifier A5, and is connected to the wave The input end of the waveguide coupler A8 and the output end of the waveguide coupler A8 are connected to the radar antenna feed system. The coupling end of the waveguide coupler A8 transmits a radio frequency signal of about 0.1W to the input end of the detection circuit B4. During debugging, the output end of the waveguide coupler A8 can be connected to a high-power load, and a power meter can be connected to the coupling end to measure the peak power output of the transmitter. If the peak power value is small or the fluctuation within the band is large, a matching block can be used to adjust it on the four-way two-level 300W power amplifier A5. Finally, the peak power can be adjusted to meet the index requirements, and the fluctuation within the band is controlled within 1dB.

[0033] The output of detection circuit B4 is connected to the input of BITE control circuit B1, which amplifies, shapes, compares, and evaluates the detection signal. It then transmits the output power value and fault information to the radar monitoring system via external communication. BITE control circuit B1 also receives the operating voltage and current from the primary and secondary power amplifier modulation circuits B2 and B3, as well as the activation status of the transmitter's internal temperature relay, to determine whether the transmitter is experiencing faults such as overvoltage, overcurrent, or overtemperature. If any of these faults occur, the TTL control signal is immediately disabled to protect the transmitter from damage.

[0034] Because the first-stage 300W power amplifier A1 and the 4-way second-stage 300W power amplifier A5 are high-power heating devices, the transmitting component is equipped with a special fan unit C0 to cool the heat sink on the back of the component.

[0035] The present invention is based on GaN power tube devices and adopts multi-channel waveguide power synthesis technology, which can achieve stable high-power output in the 9.3-9.5GHz frequency range. At the same time, high-precision pulse envelope adjustment technology can realize the shaping of the RF output envelope and achieve control of the RF output spectrum. This enables this type of transmitter to meet the different needs of different users and adapt to different application scenarios.

[0036] The above detailed description of the preferred embodiments of the present invention should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. An all-solid-state X-band transmitter based on GaN field-effect transistors, characterized by: It includes a power amplifier chain unit, a control and signal detection unit and a fan unit; wherein, the input end of the power amplifier chain unit is connected to the radio frequency input signal, the output end of the power amplifier chain unit outputs the radio frequency output signal, the input end of the control and signal detection unit is connected to the door frame differential signal, the external communication signal and the local control signal, and the output end of the control and signal detection unit outputs the transmitter working status signal, fault signal and analog parameter; the power amplifier chain unit and the control and signal detection unit are bidirectionally communicated, and the fan unit provides the air volume required for the heat dissipation of the transmitter.

2. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 1, characterized in that: The power amplifier chain unit includes a first-stage 300W power amplifier, a first isolator, a one-to-four power splitter, a second isolator, a second-stage 300W power amplifier, a third isolator, a four-in-one power combiner and a waveguide coupler; wherein, the input end of the first-stage 300W power amplifier is connected to the RF input signal, and the output end of the first-stage 300W power amplifier is connected to the input end of the first isolator; the output end of the first isolator is connected to the input end of the one-to-four power splitter, the output end of the one-to-four power splitter is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the second-stage 300W power amplifier, the output end of the second-stage 300W power amplifier is connected to the input end of the third isolator, the output end of the third isolator is connected to the input end of the four-in-one power combiner, the output end of the four-in-one power combiner is connected to the input end of the waveguide coupler, the output end of the waveguide coupler outputs the RF output signal, and the coupling end of the waveguide coupler is connected to the input end of the control and signal detection unit.

3. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 2, characterized in that: The control and signal detection unit includes a BITE control circuit, a first-level power amplifier modulation circuit, a second-level power amplifier modulation circuit and a detection circuit; the input end of the BITE control circuit is respectively connected to the door frame differential signal, the external communication signal and the local control signal, and the output end of the BITE control circuit is respectively connected to the first-level power amplifier modulation circuit and the second-level power amplifier modulation circuit; the output end of the first-level power amplifier modulation circuit is connected to the first-level 300W power amplifier; the output end of the second-level power amplifier modulation circuit is connected to the second-level 300W power amplifier, the input end of the detection circuit is connected to the waveguide coupler, and the output end of the detection circuit outputs the detection signal to the BITE control circuit.

4. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 2, characterized in that: The first-stage 300W power amplifier and the second-stage 300W power amplifier both include a GaN field-effect transistor, the source of the field-effect transistor is grounded, the gate of the GaN field-effect transistor is connected to a first capacitor and a first resistor, the other end of the first capacitor is connected to the RF input signal, the other end of the first resistor is connected in parallel to the second resistor, the third capacitor and one end of the fourth capacitor, the other end of the second resistor is connected in series to the fifth capacitor, and the other ends of the third capacitor, the fourth capacitor and the fifth capacitor are grounded; the drain of the GaN field-effect transistor is connected to the second capacitor and the third resistor, the sixth capacitor, the seventh capacitor and the fourth resistor connected in parallel, the other end of the second capacitor is connected to the input end of the first isolator, the other end of the third resistor is connected in series to the eighth capacitor, and the other ends of the sixth capacitor, the seventh capacitor, the eighth capacitor and the fourth resistor are grounded.

5. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 2, characterized in that: There are four second isolators, four secondary 300W power amplifiers, and four tertiary isolators.

6. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 1, characterized in that: The frequency range of the one-to-four power divider and four-in-one power combiner is 9.3-9.5GHz, the insertion loss is 0.5dB, the isolation is greater than 20dB, the port standing wave is less than 1.3, the amplitude imbalance is ±0.5dB, the phase imbalance is ±3°, and the power tolerance is 2000W.

7. The all-solid-state X-band transmitter based on GaN field-effect transistors according to claim 1, characterized in that: The fan unit includes six DC fans.

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