C-band broadband high-power internal matching circuit
By using C-band broadband high-power internal matching circuit and quad-cell synthetic network in broadband high-power amplifiers, the limitations of frequency range and output power in the prior art are solved, and efficient matching of 4-8GHz broadband and 90W high-power output is achieved.
Patent Information
- Application Number
- CN202510133021.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-05-30
AI Technical Summary
Existing broadband high-power amplifiers have limitations in frequency range and output power, making it difficult to achieve 4-8GHz broadband and 90W high-power output at the same time.
The C-band wideband high-power internal matching circuit is adopted, including input matching circuit, output matching circuit, die, gate bias circuit and drain bias circuit, and power synthesis is achieved through a quad-cell synthesis network, and the reactive matching circuit and high Q-value ceramic materials are used to reduce losses.
It realizes broadband matching and 90W high-power output in the 4-8GHz frequency range, improving the broadband performance and transmission efficiency of GaN microwave power devices.
Smart Images
Figure CN120074402A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of broadband high-power amplifiers, relates to multi-stage reactance broadband matching technology, and specifically relates to a C-band broadband high-power internal matching circuit. Background Art
[0002] Power amplifiers are an important part of modern communication systems and wireless detection systems, and are widely used in fields such as mobile communication and unmanned driving. With the increasing requirements for transmission rate and system capacity, broadband power amplifiers that can be compatible with different frequency bands have been widely studied. High-power performance indicators can provide better detection and interference effects. Therefore, the research on broadband high-power amplifiers has extremely high practical significance.
[0003] The third-generation semiconductor materials represented by gallium nitride (GaN) have advantages such as higher saturated electron drift velocity, larger power density, and higher breakdown voltage, and are very suitable for the production of broadband high-power amplifiers.
[0004] The design requirements of broadband amplifiers are to maintain the gain of the amplifier unchanged within a relatively wide frequency range to ensure the gain flatness and circuit stability of the amplifier. Currently, relatively common and mature solutions for broadband gain compensation design of amplifiers include: reactance matching circuits, traveling-wave distributed circuits, feedback circuits, and lossy matching circuits. Distributed power amplifiers can achieve a bandwidth of about 10 octaves, but have problems such as large losses, small output power, and low efficiency. Lossy matching expands the bandwidth by adding lossy elements, but has problems such as increased loss and reduced gain. The structure of the reactance matching circuit is simple, and multi-stage impedance transformation can be used to expand the bandwidth. However, the number of matching stages cannot be increased infinitely. The increase in the number of matching stages will bring greater matching loss, reduce the output power and efficiency. Generally, a matching bandwidth of about 3 octaves can be achieved.
[0005] Power combining is the general technical route for high-power internal matching devices. If a single chip is used to implement this broadband power amplifier, limited by the power capacity of the single chip, the output power is usually about 20W. Using a single chip for power combining will result in increased loss and reduced combining efficiency. Summary of the Invention
[0006] Object of the Invention: The object of the present invention is to provide a C-band broadband high-power internal matching circuit, which can simultaneously achieve two indicators of 4-8 GHz broadband and 90W high-power output, further improve the broadband performance of GaN microwave power devices, and achieve a larger working bandwidth, a larger output power, and a higher emission efficiency.
[0007] Technical solution: A C-band broadband high-power internal matching circuit structure of the present invention is applicable to the C-band in the frequency range of 4 - 8 GHz, and includes an input matching circuit, an output matching circuit, a die, a gate bias circuit, and a drain bias circuit; the input matching circuit is connected between the signal input terminal and the gate of the die, and the output matching circuit is connected between the drain of the die and the signal output terminal; the gate bias circuit is arranged at the gate of the die, and the drain bias circuit is arranged at the drain of the die; the gate bias circuit is connected in parallel with the input matching circuit, and the drain bias circuit is connected in parallel with the output matching circuit;
[0008] The C-band broadband high-power internal matching circuit realizes power synthesis by using a four-cell synthesis network.
[0009] Further, the input matching circuit includes a second DC-blocking capacitor, a second power divider, a first power divider, a second grounding capacitor, and a second microstrip line connected in sequence from the signal input terminal to the input terminal of the die;
[0010] Among them, the output terminal of the second DC-blocking capacitor is divided into two paths, each path is connected to a second power divider, the output terminal of each second power divider is further divided into two paths, and each path is sequentially connected with a first power divider, a second grounding capacitor, and a second microstrip line.
[0011] Further, the output matching circuit adopts a reactive matching network, and the output matching circuit includes a first microstrip line, a first grounding capacitor, a first synthesizer, a second synthesizer, a first DC-blocking capacitor, a first 50-ohm microstrip line, and a second 50-ohm microstrip line connected in sequence from the output terminal of the die to the signal output terminal;
[0012] Among them, the output terminal of the die is divided into four paths, and each path is connected with a first microstrip line, a first grounding capacitor, and a first synthesizer; the output terminals of the four first synthesizers are connected in pairs, and then are respectively connected to the input terminal of the first DC-blocking capacitor through a second synthesizer.
[0013] Further, the input matching circuit and the output matching circuit adopt reactive matching circuits, which have the advantages of low loss, large power capacity, and simple circuit structure.
[0014] Further, the reactive matching circuit is made of a high-Q ceramic material, which reduces the loss of the circuit and improves the performance indexes of output power and efficiency.
[0015] Further, the gate bias circuit is a series RC network, and the gate bias circuit includes a large-value resistor and a first decoupling capacitor. One end of the large-value resistor is connected to the G pole of the die, and the other end is respectively connected to the G pole voltage V of the die GS, a first decoupling capacitor, with the other end of the first decoupling capacitor grounded. Using a large-value resistor can not only improve the stability of the amplifier and adjust the gain of the power amplifier, but also prevent the circuit from self-exciting oscillation. The first decoupling capacitor filters out interference signals within the frequency band.
[0016] Further, the drain bias circuit is a series LC network. The drain bias circuit includes a stub in the first microstrip line and a second decoupling capacitor. One end of the stub in the first microstrip line is connected to the D pole of the die, and the other end is respectively connected to the D pole voltage V of the die DS , a second decoupling capacitor, with the other end of the second decoupling capacitor grounded. The stub can expand the bandwidth.
[0017] Further, the end of the stub in the first microstrip line is bonded to the second decoupling capacitor by a gold wire to achieve radio frequency short circuit.
[0018] Further, the second microstrip line, the first power divider, and the second power divider are loaded on an alumina ceramic substrate, and the second grounding capacitor is loaded on the ceramic substrate.
[0019] The first microstrip line, the first synthesizer, and the second synthesizer are loaded on an alumina ceramic substrate, and the first grounding capacitor is loaded on the ceramic substrate.
[0020] Beneficial effects: Compared with the prior art, the remarkable technical effects of the present invention are as follows:
[0021] Both the input matching circuit and the output matching circuit use reactance-type matching circuits, which have the advantages of low loss, large power capacity, and simple circuit structure. The bandwidth is expanded by loading the first power divider, the second power divider, and the stub. The loss of the circuit is reduced by using low-resistance circuit design techniques such as high-Q ceramic materials, and the performance indicators of output power and efficiency are improved.
[0022] The present invention uses a four-cell synthesis network for power synthesis to improve the output power of the C-band power amplifier, and finally realizes the output index of 90W high power. Each small cell has two sections of stubs to ground. At the same time, the first microstrip line is designed wider, and the electromagnetic distribution is uniform through symmetric design, which is beneficial to the broadband design of the C-band power amplifier.
[0023] The gate bias circuit and the drain bias circuit adopted by the present invention not only provide voltage and current for the power amplifier, but also play a role in isolating AC signals and filtering out clutter in DC signals.
[0024] The large-value resistor in the gate bias circuit can not only improve the stability of the amplifier and adjust the gain of the power amplifier, but also prevent the circuit from self-exciting oscillation. The first decoupling capacitor filters out interference signals within the frequency band.
[0025] The end of the stub in the drain bias circuit is wire-bonded to the second decoupling capacitor (using a MOS capacitor or a ceramic capacitor) through a gold wire to achieve RF short-circuit. Description of the Drawings
[0026] Figure 1 This is the circuit layout of a C-band broadband high-power internal matching circuit disclosed in an embodiment of the present invention;
[0027] Figure 2 This is the circuit topology diagram of a C-band broadband high-power internal matching circuit disclosed in an embodiment of the present invention;
[0028] Figure 3 This is a schematic diagram of the output power and efficiency of the power amplifier disclosed in an embodiment of the present invention. Detailed Embodiments
[0029] The technical solutions of the present invention will be introduced in detail below in combination with the detailed embodiments and the drawings in the specification.
[0030] As Figure 1 shown, the C-band broadband high-power internal matching circuit of the present invention designs the following components: package 1, die 2, first microstrip line 3, first grounding capacitor 4, first synthesizer 5, second synthesizer 6, first DC-blocking capacitor 7, first 50-ohm microstrip line 8, second 50-ohm microstrip line 9, second microstrip line 10, second grounding capacitor 11, first power divider 12, second power divider 13, second DC-blocking capacitor 14, first decoupling capacitor 15, large-value resistor 16, second decoupling capacitor 17.
[0031] The C-band broadband high-power internal matching circuit of the present invention is adapted to a GaN die with a gate width of 7.2 mm to 10 mm. It is recommended that the GaN die size be 4 * 0.8 mm to improve the heat dissipation capacity. The structure of this internal matching circuit is applicable to the C-band in the frequency range of 4 - 8 GHz and includes an input matching circuit, an output matching circuit, die 2, a gate bias circuit, and a drain bias circuit. The input matching circuit is connected between the signal input terminal and the gate of die 2, and the output matching circuit is connected between the drain of die 2 and the signal output terminal; the gate bias circuit is arranged at the gate of die 2, and the drain bias circuit is arranged at the drain of die 2. The gate bias circuit is connected in parallel with the input matching circuit, and the drain bias circuit is connected in parallel with the output matching circuit.
[0032] The input matching circuit and the output matching circuit adopt low-loss circuit design techniques, specifically, a reactance matching circuit is used. In this embodiment, the reactance matching circuit is made of a high-Q ceramic material. By adopting low-resistance circuit design techniques such as high-Q ceramic materials, the loss of the circuit is reduced, and the performance level of the existing power amplifier in this frequency band is improved. The input matching circuit and the output matching circuit are designed using low-resistance techniques. By adopting reactance matching and high-Q ceramic materials, the circuit loss is reduced, and the miniaturization and high performance of the amplifier are achieved.
[0033] As Figure 1 and Figure 2 shown, Figure 2 L1 and Z5 in Figure 1 correspond to the first microstrip line 3, C3 corresponds to the first grounding capacitor 4, Z6 and Z7 correspond to the first synthesizer 5, Z8 corresponds to the second synthesizer 6, C4 corresponds to the first DC-blocking capacitor 7, L3 corresponds to the stub of the first microstrip line 3, L2 and Z4 correspond to the second microstrip line 10, C2 corresponds to the second grounding capacitor 11, Z3 and Z2 correspond to the first power divider 12, Z1 corresponds to the second power divider 13, C1 corresponds to the second DC-blocking capacitor 14, C5 corresponds to the first decoupling capacitor 15, R1 corresponds to the high-value resistor 16, and C6 corresponds to the second decoupling capacitor 17.
[0034] The input matching circuit includes a second microstrip line 10, a second grounding capacitor 11, a first power divider 12, a second power divider 13, and a second DC-blocking capacitor 14 disposed on the package 1. The second DC-blocking capacitor 14, the second power divider 13, the first power divider 12, the second grounding capacitor 11, and the second microstrip line 10 are connected in sequence from the signal input end to the input end of the die 2, wherein the second microstrip line 10 is connected to the die 2. Among them, the output end of the second DC-blocking capacitor 14 is divided into two paths, and each path is connected to a second power divider 13. The output end of each second power divider 13 is further divided into two paths, and each path is sequentially connected with a first power divider 12, a second grounding capacitor 11, and a second microstrip line 10.
[0035] The input matching circuit includes a first-level LC structure, a first power divider 12, a second power divider 13, and a first DC-blocking capacitor 14, which belongs to reactance matching. The microstrip line 10 connected to the die represents the inductor in the first-level LC structure, and the capacitor in the first-level LC structure is the second grounding capacitor 11. Gold wires are used for bonding between each component and the microstrip line.
[0036] The output matching circuit includes a first microstrip line 3, a first grounding capacitor 4, a first synthesizer 5, a second synthesizer 6, a first DC-blocking capacitor 7, a first 50-ohm microstrip line 8, and a second 50-ohm microstrip line 9 disposed on the package 1. The first microstrip line 3, the first grounding capacitor 4, the first synthesizer 5, the second synthesizer 6, the first DC-blocking capacitor 7, the first 50-ohm microstrip line 8, and the second 50-ohm microstrip line 9 are sequentially connected from the output end of the die 2 to the signal output end. Among them, the first microstrip line 3 is connected to the die 2. The output end of the die 2 is divided into four paths, and each path is connected with a first microstrip line 3, a first grounding capacitor 4, and a first synthesizer 5; the output ends of the four first synthesizers 5 are connected in pairs, and then are respectively connected to the input end of the first DC-blocking capacitor 7 through a second synthesizer 6.
[0037] The C-band broadband high-power internal matching circuit of the present invention uses a four-cell synthesis network technology for power synthesis to achieve a larger output power. Each small cell of the present invention has two sections of short-circuited stubs (the short-circuited microstrip lines on both sides of the first microstrip line 3). At the same time, the first microstrip line is designed wider, and the electromagnetic distribution is made uniform through symmetric design, which is beneficial to the broadband design of the C-band power amplifier.
[0038] The output matching circuit includes a first-level LC structure, a first synthesizer 5, a second synthesizer 6, and a second DC-blocking capacitor 7, which belongs to reactance matching. The first microstrip line 3 connected to the die represents the inductor in the first-level LC structure, and the capacitor in the first-level LC structure is the first grounding capacitor 4. The present invention uses a section of short-circuited stub (the short-circuited microstrip lines on both sides of the first microstrip line 3) to eliminate the imaginary part of the die impedance and expand the bandwidth. Then, a first-level LC structure is used to increase the impedance, and finally, the impedance is transformed to 50 ohms through multiple 1 / 4-wavelength lines (the first synthesizer 5 and the second synthesizer 6). Gold wires are used for bonding between each component and the microstrip line.
[0039] Both the input matching circuit and the output matching circuit use reactance matching circuits, which have the advantages of low loss, large power capacity, and simple circuit structure. The bandwidth is expanded by loading multiple 1 / 4-wavelength lines. By adopting low-resistance circuit design technologies such as high-Q ceramic materials, the loss of the circuit is reduced, and the performance indicators of output power and efficiency are improved.
[0040] The gate bias circuit is connected to the die 2 at the input matching circuit end. Specifically as follows: The gate bias circuit is a series RC network. The gate bias circuit includes a large-value resistor 16 and a first decoupling capacitor 15. One end of the large-value resistor 16 is connected to the G pole of the die 2, and the other end is respectively connected to the G pole voltage V of the die 2 GS , the first decoupling capacitor 15, and the other end of the first decoupling capacitor 15 is grounded.
[0041] The drain bias circuit is connected to the first microstrip line 3 connecting the die at the output matching circuit end. Specifically as follows: The drain bias circuit is a series LC network. The drain bias circuit includes a stub in the first microstrip line 3 and a second decoupling capacitor 17. One end of the stub in the first microstrip line 3 is connected to the D pole of the die 2, and the other end is respectively connected to the D pole voltage V of the die 2 DS , the second decoupling capacitor 17, and the other end of the second decoupling capacitor 17 is grounded.
[0042] In this embodiment, the end of the stub in the first microstrip line 3 is wire-bonded to the second decoupling capacitor 17 by gold wire to achieve RF short circuit. The second decoupling capacitor 17 is a MOS capacitor or a ceramic capacitor
[0043] The gate bias circuit and the drain bias circuit not only provide voltage and current for the power amplifier, but also play the role of isolating AC signals and filtering out clutter in DC signals. The large-value resistor in the gate bias circuit can not only improve the stability of the amplifier and adjust the gain of the power amplifier, but also avoid self-excited oscillation of the circuit. The first decoupling capacitor filters out interference signals within the frequency band. The end of the stub in the drain bias circuit is wire-bonded to a MOS capacitor or a ceramic capacitor by gold wire to achieve RF short circuit.
[0044] The first microstrip line 3, the first synthesizer 5, the second synthesizer 6, the second microstrip line 10, the first power divider 12, and the second power divider 13 are loaded on an alumina ceramic substrate with a dielectric constant of 9.9, and the first ground capacitor 4 and the second ground capacitor 11 are loaded on a ceramic substrate with a dielectric constant of 85.
[0045] Both the input matching circuit and the output matching circuit of the present invention are reactive matching networks, which are composed of multi-stage tapered microstrip lines loaded with decoupling and matching capacitors, and the working bandwidth is extended by increasing the tapered number of the microstrip line structure of the matching circuit to solve the limitation of the relatively narrow bandwidth of reactive matching. The present invention is adapted to GaN dies with a large gate width of 7.2 mm to 10 mm, and the die size of 5×0.8 mm is recommended to meet the high heat dissipation requirements of high-power amplifiers. The power amplifier implemented by the present invention has a working voltage of 28 V, can achieve a working bandwidth of 4 - 8 GHz, an output power of ≥90 W, and a drain efficiency of ≥36%. The internal matching circuit proposed by the present invention is adapted to GaN dies with a gate width of 7.2 mm to 10 mm, and the GaN die size of 4*0.8 mm is recommended to improve the heat dissipation capacity. The present invention includes two internal matching circuit structures, namely input and output. The present invention adopts a mature ceramic substrate processing technology, and the ceramic substrate materials include quartz, alumina, and barium carbonate. The wire-bonding process is used between circuit structures. The present invention is easy to implement and easy to produce.
[0046] The internal matching circuit structure of the present invention can achieve high-power internal matching in the range of 4 - 8 GHz, simplify the synthesis design, and improve the synthesis efficiency. It gives full play to the high-power and high-efficiency characteristics of the internal matching circuit, achieving an output power of 90 W and a drain efficiency greater than 36%.
[0047] As Figure 3 shown Figure 3 is the test result diagram of the broadband high-power amplifier in the specific implementation, which are the output power and the drain efficiency respectively. In the frequency range of 4 - 8 GHz, at a saturated input power of 42 dBm, the typical saturated output power is 90 W, and the power flatness is ±1 dB. The gain is greater than 7 dB, and the saturated drain efficiency is 36% - 52%.
Claims
1. A C-band broadband high-power internal matching circuit, characterized in that: Suitable for C-band in the frequency range of 4-8 GHz, comprising an input matching circuit, an output matching circuit, a tube core (2), a gate bias circuit and a drain bias circuit; The input matching circuit is connected between the signal input terminal and the gate of the tube core (2), and the output matching circuit is connected between the drain of the tube core (2) and the signal output terminal; the gate bias circuit is arranged at the gate of the tube core (2), and the drain bias circuit is arranged at the drain of the tube core (2); the gate bias circuit is connected in parallel with the input matching circuit, and the drain bias circuit is connected in parallel with the output matching circuit; The C-band broadband high-power internal matching circuit adopts a quad-cell synthesis network to achieve power synthesis.
2. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The input matching circuit comprises a second DC blocking capacitor (14), a second power divider (13), a first power divider (12), a second grounding capacitor (11) and a second microstrip line (10) which are sequentially connected from the signal input end to the input end of the tube core (2); The output end of the second DC blocking capacitor (14) is divided into two paths, each path is connected to a second power divider (13), and each output end of the second power divider (13) is further divided into two paths, each path is sequentially connected to the first power divider (12), the second grounding capacitor (11) and the second microstrip line (10).
3. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The output matching circuit comprises a first microstrip line (3), a first grounding capacitor (4), a first synthesizer (5), a second synthesizer (6), a first DC blocking capacitor (7), a first 50 ohm microstrip line (8) and a second 50 ohm microstrip line (9) which are sequentially connected from the output end of the tube core (2) to the signal output end; The output end of the tube core (2) is divided into four paths, each of which is connected to a first microstrip line (3), a first grounding capacitor (4), and a first synthesizer (5); the output ends of the four first synthesizers (5) are connected in pairs, and then respectively connected to the input end of the first DC blocking capacitor (7) through a second synthesizer (6).
4. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The input matching circuit and the output matching circuit adopt reactance matching circuits.
5. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The reactance matching circuit is made of high-Q value ceramic material.
6. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The gate bias circuit is a series RC network, comprising a large resistance resistor (16) and a first decoupling capacitor (15), one end of the large resistance resistor (16) is connected to the G pole of the tube core (2), and the other end is connected to the G pole voltage V GS , a first decoupling capacitor (15), the other end of the first decoupling capacitor (15) is grounded.
7. The C-band broadband high-power internal matching circuit according to claim 1, characterized in that: The drain bias circuit is a series LC network, comprising a short stub in the first microstrip line (3) and a second decoupling capacitor (17), one end of the short stub in the microstrip line (3) is connected to the D pole of the tube core (2), and the other end is connected to the D pole voltage V DS , a second decoupling capacitor (17), the other end of the second decoupling capacitor (17) is grounded.
8. The C-band broadband high-power internal matching circuit according to claim 7, characterized in that: The end of the short stub in the first microstrip line (3) is bonded to the second decoupling capacitor (17) through a gold wire to achieve a radio frequency short circuit.
9. The C-band broadband high-power internal matching circuit according to claim 4, characterized in that: The second microstrip line (10), the first power divider (12), and the second power divider (13) are loaded on an alumina ceramic substrate, and the second grounding capacitor (11) is loaded on the ceramic substrate.
10. The C-band broadband high-power internal matching circuit according to claim 5, characterized in that: The first microstrip line (3), the first synthesizer (5), and the second synthesizer (6) are loaded on an alumina ceramic substrate, and the first grounding capacitor (4) is loaded on the ceramic substrate.