Ku frequency band 50W slide glass type power amplifier

Abstract

The utility model discloses a Ku frequency band 50W slide glass type power amplifier, which belongs to the technical field of microwave and millimeter wave and comprises two GaN power amplifier chips, an input thin film circuit, an output thin film circuit, four power resistance loads, four large chip capacitors, sixteen small chip capacitors, a slide glass and the like. The saturation output power of the GaN power amplifier chip is 45.5 dBm (namely 35W); the input film circuit is composed of an improved Gysel power divider and a power supply microstrip. The output thin film circuit is composed of an improved Gysel power combiner and a power supply microstrip. The power resistance load can bear a continuous wave signal with the power of 20W; the capacitance of the large chip is 1000pF, and the capacitance of the small chip is 100pF; all the components are soldered on a slide glass in an eutectic manner and are interconnected through a gold belt or a gold wire. The Ku frequency band 50W power amplifier module has the characteristics of small volume, light weight, good heat dissipation and simple structure, and solves the problems of large volume and heavy weight of the existing Ku frequency band 50W power amplifier module.

Description

Technical Field

[0001] The utility model relates to a Ku-band 50W chip-mounted power amplifier, belonging to the technical field of microwave and millimeter wave, and is particularly suitable for being applied to a Ku-band solid-state power amplifier or a transmitter in a satellite communication microwave channel. Background Technique

[0002] With the vigorous development and commercial promotion of satellite communication technology, the demand for satellite vehicle stations and portable stations by users has increased, and satellite terminal products have also been developing in the direction of miniaturization and portability. The Ku-band 40W transmitter is a common device in these two station types. After more than a decade of development, its weight has gradually decreased from the initial 15 kg to about 3 kg. In this process, the gallium nitride (GaN) power amplifier chip replacing the gallium arsenide (GaAs) power amplifier chip has played a decisive role. At present, users have put forward the research and development requirement that the weight of the Ku-band 40W transmitter is not greater than 2 kg. To ensure that the output power of the transmitter is greater than 40W within the full temperature range of -40°C to +60°C, the output power of the built-in power amplifier module should be not less than 50W.

[0003] At present, the maximum output power of domestic Ku-band GaN power amplifier chips is 35W (working in continuous wave mode). To obtain an output power of not less than 50W, it is necessary to synthesize the power of two chips. In recent years, domestic scholars have conducted some research on the power synthesis method of Ku-band GaN power amplifier chips. In December 2020, Liu Qiang published "Design of a Power Combiner for Satellite Communication Transmitters" in the journal "Digital Communication World", and used the combination of E-plane T-junction and waveguide-microstrip conversion to synthesize the power of two domestic 35W power amplifier chips; in April 2021, Peng Lekang used the combination of branch waveguide hybrid and waveguide-microstrip conversion to synthesize the power of two imported TGA2239-CP chips in his master's thesis "Ku-band Satellite Communication Ground Transmitter Module", and the final weight of the developed whole machine was 4.407 kg; in May 2022, Lu Chengyi made a microstrip branch line coupler based on the Rogers soft substrate RT5880 in his master's thesis "Design and Implementation of Ku-band Up-conversion Power Amplifier" to perform planar power synthesis on two domestic 35W power amplifier chips, and finally developed a 50W transmitter. The power synthesis structures adopted in the above papers have relatively large sizes, and the developed power amplifier modules are large in volume and heavy in weight, and it is impossible to realize a Ku-band 40W transmitter within 2 kg. Content of the Utility Model

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the utility model proposes a Ku-band 50W chip-mounted power amplifier, which has the characteristics of small volume, light weight, good heat dissipation and simple structure.

[0005] To achieve the above object, the technical solution adopted by the utility model is as follows:

[0006] A Ku-band 50W chip-mounted power amplifier includes two GaN power amplifier chips (1), an input thin-film circuit (2), an output thin-film circuit (3), four power resistor loads (4), four chip capacitors I (5), sixteen chip capacitors II (6), and a chip carrier (7);

[0007] The GaN power amplifier chips, microstrip power dividers, microstrip power combiners, power resistor loads, chip capacitors I, and chip capacitors II are all eutectically welded onto the chip carrier and interconnected by gold strips or gold wires;

[0008] Among them, the main body of the input thin-film circuit is a Gysel power divider, and the main body of the output thin-film circuit is a Gysel power combiner; both the Gysel power divider and the Gysel power combiner are five-port devices, including an input port, two output ports, and two isolation ports;

[0009] The surface of the chip carrier is divided into three areas: left, middle, and right; among them, a boss is arranged in the middle area, and three grooves penetrating the left area and the right area are arranged along the extension direction of the boss; on the boss, the positions between two adjacent grooves are used for the positioning and eutectic welding of two GaN power amplifier chips, and the groove positions are used for arranging the corresponding number of chip capacitors II; the left area and the right area are used for the positioning and eutectic welding of the input thin-film circuit and the output thin-film circuit;

[0010] The chip capacitors I are located in the left area and the right area and are respectively arranged on both sides of the two end grooves; two chip capacitors I, eight chip capacitors II, and microstrip lines around each GaN power amplifier chip are connected by gold wires or gold strips to provide negative voltage for the gates of the two GaN power amplifier chips and positive voltage for the drains; for the Gysel power divider and the Gysel power combiner, both port 2 and port 3 are connected to the corresponding GaN power amplifier chips by gold wires, and the isolation ports are connected to the power resistor loads.

[0011] Further, the left area and the right area are mirror-symmetrical.

[0012] Further, among the three grooves, eight chip capacitors II are arranged in the middle groove, and four chip capacitors II are respectively arranged in the two end grooves.

[0013] Further, for the Gysel power divider and the Gysel power combiner, port 2 and port 3 face the same direction and are opposite to the direction of port 1; port 4 and port 5 are isolation ports, and they face opposite directions and are perpendicular to the direction of port 1.

[0014] Further, the chip capacitor I is a 1000 pF single-layer capacitor, and the chip capacitor II is a 100 pF single-layer capacitor.

[0015] Further, four through holes with a diameter of 2 mm are provided at the four corners of the carrier wafer to facilitate the fixation of the carrier wafer.

[0016] Further, the carrier wafer is made of tungsten copper material with a 2-μm gold plating on the surface; the substrate material of the input thin-film circuit is sintered alumina ceramic (Al 2 O 3 ), with a purity of 99.6%, a thickness of 0.508 mm, a dielectric constant of 9.7 in the Ku band; and the gold layer thickness is 4 μm.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] 1. The present utility model proposes a Ku-band 50W carrier wafer type power amplifier with an operating frequency of 13.75 GHz - 14.5 GHz, which has the characteristics of small volume, light weight, good heat dissipation, and simple structure, and solves the problems of large volume and heavy weight of the existing Ku-band 50W power amplifier module.

[0019] 2. In traditional Ku-band microstrip power dividers, the thin-film resistors used in Wilkinson power dividers cannot withstand large power; the coupled lines of Lange power dividers are narrow, making gold wire bonding difficult; the present utility model proposes an improved Gysel power divider, which has the characteristics of small insertion loss, good amplitude-phase consistency, high isolation, good input-output return loss, and simple structure, and two isolation ports can be externally connected to power load resistors, which can withstand large power.

[0020] 3. The proposal of the present utility model provides strong technical support for the development of a Ku-band 40W transmitter within 2 kg, and also provides a technical reference for the miniaturization design of Ku-band solid-state power amplifiers, and has high popularization and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the principle block diagram of the present utility model;

[0022] Figure 2 is the three-dimensional structure diagram of the external shape of the present utility model;

[0023] Figure 3 is the three-dimensional structure diagram of the disassembly of the present utility model;

[0024] Figure 4 is the planar structure diagram of the present utility model;

[0025] Figure 5 is the structure diagram of the improved Gysel power divider;

[0026] Figure 6 is the amplitude curve graph of Port 2 and Port 3 of the improved Gysel power divider;

[0027] Figure 7 is the phase curve graph of Port 2 and Port 3 of the improved Gysel power divider;

[0028] Figure 8 is the isolation curve graph of Port 2 and Port 3 of the improved Gysel power divider;

[0029] Figure 9 is the input and output return loss curve graph of the improved Gysel power divider. Detailed implementation mode

[0030] For the convenience of those skilled in the art to understand the technical content of the present utility model, the following further explains the content of the present utility model in conjunction with the accompanying drawings.

[0031] A Ku-band 50W chip-mounted power amplifier, which consists of two GaN power amplifier chips, an input thin-film circuit, an output thin-film circuit, four power resistor loads, four large chip capacitors, sixteen small chip capacitors, a chip carrier, etc. The GaN power amplifier chips, microstrip power dividers, microstrip power combiners, power resistor loads, large chip capacitors, small chip capacitors, etc. are all eutectically welded on the chip carrier and interconnected by gold strips or gold wires.

[0032] The GaN power amplifier chip is a GaN high-power amplifier chip produced by the 13th Research Institute of CETC. In the frequency range of 13.0GHz - 15.5GHz, the saturated output power of this chip is 45.5dBm (i.e., 35W).

[0033] The input thin-film circuit is composed of an improved Gysel power divider and a power supply microstrip. The improved Gysel power divider is a five-port device, including an input port, two output ports, and two isolation ports; signals enter the power divider from the input port, and two output ports output two signals with equal amplitude and in-phase, and the two isolation ports are respectively connected to power resistor loads; the traditional Gysel power divider has a large size, which limits its popularization and application. The present utility model optimizes its structure, rotates the two isolation ports by 90°, and then connects them to the power resistor loads through gold wire bonding, effectively reducing the size of the divider in the signal transmission direction. The power supply microstrip is a microstrip line with a width of not less than 0.4mm, and the microstrip line, large chip capacitor, and small chip capacitor are interconnected by gold strips or gold wires to provide a negative voltage for the gates of the two GaN power amplifier chips.

[0034] The output thin-film circuit consists of an improved Gysel power combiner and a power supply microstrip, and its layout is exactly the same as that of the input thin-film circuit. The improved Gysel power combiner is a five-port device, including two input ports, one output port, and two isolation ports; two signals with equal amplitude and in-phase enter the power combiner from the two input ports respectively, and are combined into one signal at the output port, and the two isolation ports are respectively connected to power resistor loads. The power supply microstrip is a microstrip line with a width of not less than 0.4 mm, and the microstrip line, large chip capacitor, and small chip capacitor are interconnected by gold strips or gold wires to provide positive voltage for the drains of two GaN power amplifier chips.

[0035] The power resistor load is a GaN power resistor chip produced by the 13th Research Institute of CETC, and can withstand a continuous wave signal with a maximum power of 20W.

[0036] The large chip capacitor is a 1000 pF single-layer capacitor, and the small chip capacitor is a 100 pF single-layer capacitor.

[0037] There are two bosses in the middle of the carrier wafer for the positioning and eutectic welding of two GaN power amplifier chips; there is a slightly lower step between the two bosses for placing eight small chip capacitors; there is a slightly lower step on each of the upper and lower sides of the two bosses for placing four small chip capacitors respectively; there are two symmetrically lower planes on the left and right sides of the carrier wafer for the positioning and eutectic welding of the input thin-film circuit and the output thin-film circuit; there are four through holes at the four corners of the carrier wafer to facilitate the fixing of the carrier wafer.

[0038] Refer to Figures 1 - 4 , the utility model relates to a Ku-band 50W carrier wafer type power amplifier, including two GaN power amplifier chips 1, an input thin-film circuit 2, an output thin-film circuit 3, four power resistor loads 4, four large chip capacitors 5, sixteen small chip capacitors 6, a carrier wafer 7, etc. The GaN power amplifier chips 1, the input thin-film circuit 2, the output thin-film circuit 3, the power resistor loads 4, the large chip capacitors 5, and the small chip capacitors 6, etc. are all eutectically welded on the carrier wafer 7 and interconnected by gold strips or gold wires.

[0039] Furthermore, the GaN power amplifier chip 1 is a GaN high-power amplifier chip produced by the 13th Research Institute of CETC, with the model number NC116129C-1315P35 and the size of 5.00 mm × 6.65 mm × 0.08 mm; within the frequency range of 13.0 GHz - 15.5 GHz, the saturated output power of this chip is 45.5 dBm (i.e., 35W); the typical values of the chip's DC electrical parameters are: the gate operating voltage is -1.8V, the drain operating voltage is +28V, the static drain current is 3A, and the dynamic drain current is 4.5A.

[0040] Further, the input thin-film circuit 2 is composed of an improved Gysel power divider 8 and a power supply microstrip 9. Refer to Figure 5 , the improved Gysel power divider 8 is a five-port device, including an input port (port 1), two output ports (port 2 and port 3), and two isolation ports (port 4 and port 5); signals enter the power divider from the input port, and two output ports output two signals with equal amplitude and in-phase, and the two isolation ports are respectively connected to power resistor loads 4; the traditional Gysel power divider has a large size, which limits its popularization and application. The present utility model optimizes its structure, rotates the two isolation ports by 90°, and then connects them to the power resistor load through gold wire bonding, effectively reducing the size of the divider in the signal transmission direction. The power supply microstrip 9 is a microstrip line with a width of not less than 0.4 mm, and the microstrip line, large chip capacitor 5 and small chip capacitor 6 are interconnected by gold tape or gold wire to provide a negative voltage for the gates of the two GaN power amplifier chips 1.

[0041] Specifically, the substrate material used for the input thin-film circuit 2 is fired alumina ceramic (Al 2 O 3 ), with a purity of 99.6%, a thickness of 0.508 mm, and a dielectric constant of 9.7 in the Ku band; the thickness of the gold layer is 4 μm.

[0042] Figures 6 - 8 They are respectively the amplitude curve graph, phase curve graph, and isolation degree curve graph of the output ports of the improved Gysel power divider 8, Figure 9 which are the input and output return loss curve graphs. It can be seen from the figure that in the frequency range of 13.75 GHz - 14.5 GHz, the amplitude difference between the two output ports (port 2 and port 3) is within 0.01 dB, the phase difference is within 0.3°, and the isolation degree is better than 19 dB; the return loss of the input port (port 1) is better than 20 dB, and the return loss of the output ports (port 2 and port 3) is better than 18 dB. The improved Gysel power divider 8 has the characteristics of small insertion loss, good amplitude-phase consistency, high isolation degree, good input-output return loss, and simple structure, and the two isolation ports can be externally connected to power load resistors and can withstand a large power.

[0043] The output thin-film circuit 3 is composed of an improved Gysel power combiner 10 and a power supply microstrip 11, and its layout is exactly the same as that of the input thin-film circuit 2. The improved Gysel power combiner 10 is a five-port device, including two input ports (ports 2 and 3), one output port (port 1), and two isolation ports (ports 4 and 5); two signals with equal amplitude and in-phase enter the power combiner from the two input ports respectively, and are combined into one signal at the output port, and the two isolation ports are respectively connected to the power resistor load 4. The power supply microstrip 11 is a microstrip line with a width of not less than 0.4 mm, and the microstrip line, the large chip capacitor 5 and the small chip capacitor 6 are interconnected by gold strips or gold wires to provide a positive voltage for the drains of the two GaN power amplifier chips 1.

[0044] Further, the power resistor load 4 is an NC6109C-167 type GaN power resistor chip produced by the 13th Research Institute of CETC, with a size of 1.10 mm × 0.58 mm × 0.08 mm and a microwave impedance of 50 Ω; in order to ensure its good heat dissipation, it is sintered on a tungsten-copper carrier by a gold-tin eutectic soldering process, and the maximum continuous wave signal power it can withstand is 20 W.

[0045] Further, the large chip capacitor 5 is a 1000 pF single-layer capacitor with a size of 0.9 mm × 0.9 mm × 0.18 mm; the small chip capacitor 6 is a 100 pF single-layer capacitor with a size of 0.635 mm × 0.635 mm × 0.18 mm.

[0046] Further, the carrier wafer 7 has a transverse length of 17.4 mm and a longitudinal length of 19.2 mm; there are two bosses in the middle of the carrier wafer 7 for the positioning and eutectic soldering of the two GaN power amplifier chips; there is a slightly lower step between the two bosses for placing eight small chip capacitors 6; there is a slightly lower step on each of the upper and lower sides of the two bosses for placing four small chip capacitors 6 respectively; there are two symmetrically arranged lower planes on the left and right sides of the carrier wafer 7 for the positioning and eutectic soldering of the input thin-film circuit 2 and the output thin-film circuit 3; there are four through holes with a diameter of 2 mm at the four corners of the carrier wafer to facilitate the fixation of the carrier wafer.

[0047] Specifically, the carrier wafer 7 is made of tungsten-copper material (W-10% Cu) and its surface is gold-plated with a thickness of 2 μm; in order to optimize the circuit indexes and facilitate wire bonding, it is necessary to ensure that the bonding pad heights of the GaN power amplifier chip 1, the input thin-film circuit 2, the output thin-film circuit 3, and the small chip capacitor 6 are basically the same. Therefore, the thicknesses of different positions of the carrier wafer 7 are different. The thickness at the boss position is 1.5 mm, the thickness at the two lower plane positions is 1.05 mm, and the thickness at the slightly lower step positions between the two bosses and on both sides is 1.4 mm.

[0048] In summary, the utility model has the characteristics of small volume, light weight, good heat dissipation and simple structure, solves the problems of large volume and heavy weight of the existing Ku-band 50W power amplifier module, provides strong technical support for the development of a Ku-band 40W transmitter within 2 kg, and also provides a technical reference for the miniaturized design of Ku-band solid-state power amplifiers, having high popularization and application value.

[0049] The brief working principle of the utility model is as follows:

[0050] The Ku-band signal first enters the input thin-film circuit of the utility model, is input from the input port of the improved Gysel power divider, and outputs two signals with equal amplitude and in-phase, which respectively enter two GaN power amplifier chips (saturated output power 35W); the two Ku-band signals after power amplification respectively enter the two input ports of the improved Gysel power combiner in the output thin-film circuit and are combined into one signal at the output port. As long as a Ku-band input signal with sufficient power is provided, the output power of the utility model can be ensured to be not less than 47 dBm (i.e., 50W).

[0051] The technical indicators of the utility model are as follows:

[0052] Operating frequency band: 13.75 GHz - 14.5 GHz;

[0053] Gain: ≥24 dB;

[0054] Output power: ≥47 dBm (i.e., 50W);

[0055] Power supply requirements: +28V / 4.5A (typical value); -1.8V / 1mA (typical value);

[0056] Overall dimensions: 17.4 mm × 19.2 mm × 2 mm.

[0057] Those skilled in the art will realize that the described embodiments are for helping readers understand the principle of the utility model, and it should be understood that the protection scope of the utility model is not limited to the described embodiments. For those skilled in the art, various changes and modifications can be made to the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included within the scope of the claims of the utility model.

Claims

1. A Ku-band 50W chip-mounted power amplifier, characterized in that: It comprises two GaN power amplifier chips (1), an input thin film circuit (2), an output thin film circuit (3), four power resistor loads (4), four chip capacitors I (5), sixteen chip capacitors II (6) and a carrier (7); The GaN power amplifier chip, microstrip power divider, microstrip power synthesizer, power resistor load, chip capacitor I and chip capacitor II are all eutectic welded on the carrier and interconnected by gold ribbons or gold wires; The main body of the input thin film circuit is a Gysel power divider, and the main body of the output thin film circuit is a Gysel power combiner; the Gysel power divider and the Gysel power combiner are both five-port devices, including one input port, two output ports and two isolation ports; The surface of the carrier is divided into three areas: left, middle and right; wherein, a boss is arranged in the middle area, and three grooves penetrating the left and right areas are arranged along the extension direction of the boss; on the boss, the position between two adjacent grooves is used for positioning and eutectic welding of two GaN power amplifier chips, and the groove position is used to set a corresponding number of chip capacitors II; the left and right areas are used for positioning and eutectic welding of input thin film circuits and output thin film circuits; The chip capacitor I is located in the left area and the right area, and is arranged on both sides of the two end grooves; the two chip capacitors I, 8 chip capacitors II, and microstrip lines on the periphery of each GaN power amplifier chip are connected by gold wires or gold strips, and are used to provide negative voltages for the gates of the two GaN power amplifier chips and positive voltages for the drains; the Gysel power divider and the Gysel power combiner, both ports 2 and 3 of the two are connected to the corresponding GaN power amplifier chips through gold wires, and the isolation port is connected to the power resistor load.

2. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: The left area and the right area are mirror-symmetrical.

3. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: Among the three grooves, eight chip capacitors II are arranged in the middle groove, and four chip capacitors II are arranged in the grooves at both ends respectively.

4. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: The Gysel power divider and the Gysel power combiner have ports 2 and 3 facing the same direction and facing opposite to port 1; Port 4 and port 5 are isolated ports, which are oriented in opposite directions and perpendicular to the direction of port 1.

5. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: The chip capacitor I is a 1000pF single-layer capacitor, and the chip capacitor II is a 100pF single-layer capacitor.

6. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: The four corners of the slide are provided with four through holes with a diameter of 2 mm to facilitate the fixation of the slide.

7. The Ku-band 50W chip-mounted power amplifier according to claim 1, characterized in that: The carrier is made of tungsten copper material with a surface gold plating of 2 μm; the substrate material used in the input thin film circuit is sintered alumina ceramic with a purity of 99.6%, a thickness of 0.508 mm, and a dielectric constant of 9.7 in the Ku frequency band; the thickness of the gold layer is 4 μm.

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