A high-power synthesizer combining microstrip circuit and coaxial cable

Abstract

The invention discloses a high-power synthesizer mixed with a microstrip circuit and a coaxial cable, including an input impedance Z0, one end of the input impedance Z0 is connected to one end of a fan-shaped line capacitor X3, the impedance Z0 is simultaneously connected to one end of two quarter-wavelength coaxial cables Z1, the other ends of the two quarter-wavelength coaxial cables Z1 are both connected to the fan-shaped line capacitor X1, one end of a quarter-wavelength coaxial cable Z2 and one end of a branch microstrip line Z1, the other ends of the two branch microstrip lines Z1 are connected to an isolation resistor R1, the other ends of the two quarter-wavelength coaxial cables Z2 are connected to the fan-shaped line capacitor X2, one end of a quarter-wavelength microstrip line Z3 and one end of a branch cable Z2, and the other ends of the two branch microstrip lines Z2 are connected to an isolation resistor R2. The invention has a simple structure and is easy to manufacture. The circuit has better performance, higher power, flexible routing and simple processing, and greatly improved reliability.

Description

Technical Field

[0001] The invention relates to the technical field of electronic equipment, and in particular to a high-power synthesizer that mixes a microstrip circuit and a coaxial cable. Background Art

[0002] The development of broadcasting and communication technology requires television, radar, communication and other systems to transmit higher power signals and improve the quality of transmitted signals (linearization technology and broadband modulation technology). Due to the constraints of the output power and cost of a single microwave power transistor and the requirements of linearization technology, high-power microwave transmitters mostly use power synthesis technology. The currently used power synthesis technologies include: (1) Wilkinson power synthesizer with planar microstrip circuit, which has the advantages of low cost, high input port isolation and good port matching. However, the synthesizer has a high-impedance quarter-wavelength microstrip transmission line. Due to the limitations of materials and structure, the designed microstrip line is relatively thin and long, and it is difficult to achieve thermal resistance of: <20℃ / W, and it is difficult to withstand power >100W@500MHz; the isolation resistor of the synthesizer is connected across the two input arms, and the distributed capacitance of the resistor to the ground limits the operating frequency and power. The Wilkinson power synthesizer circuit is widely used in smaller power synthesizers, non-planar direct power synthesis such as coaxial or cavity. It has the advantages of simple structure, low loss and high synthesis power. The problems are high cost, poor synthesis port matching, narrow operating frequency band and low port isolation; there are input condition restrictions. For this reason, we propose a high-power synthesizer that mixes microstrip circuits and coaxial lines to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings in the prior art and to propose a high-power synthesizer that combines a microstrip circuit and a coaxial cable.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A high-power synthesizer that mixes a microstrip circuit and a coaxial cable comprises an input impedance Z0, one end of the input impedance Z0 is connected to one end of a fan-out capacitor X3, the impedance Z0 is simultaneously connected to one end of two quarter-wavelength coaxial cables Z1, the other ends of the two quarter-wavelength coaxial cables Z1 are both connected to the fan-out capacitor X1, one end of a quarter-wavelength coaxial cable Z2 and one end of a branch microstrip line Z1, the other ends of the two branch microstrip lines Z1 are connected to an isolation resistor R1, the other ends of the two quarter-wavelength coaxial cables Z2 are connected to the fan-out capacitor X2, one end of a quarter-wavelength microstrip line Z3 and one end of the branch cable Z2, the other ends of the two branch microstrip lines Z2 are connected to the isolation resistor R2, the other ends of the two quarter-wavelength microstrip lines Z3 are both connected to one end of a branch output impedance Z0 and one end of the branch microstrip line Z3, and the other ends of the two branch microstrip lines Z3 are connected to the isolation resistor R3.

[0006] Preferably, the quarter-wavelength coaxial cable Z1 is a low-loss 100Ω impedance 1 / 4-wavelength coaxial cable.

[0007] Preferably, the quarter-wavelength coaxial cable Z2 is a low-loss 75Ω impedance 1 / 4 wavelength coaxial cable.

[0008] Preferably, the quarter-wavelength microstrip line Z3 is a 1 / 4 wavelength, 55Ω impedance microstrip line.

[0009] Preferably, the capacitor X1, the capacitor X2 and the capacitor X3 are all fan-shaped line capacitors for impedance matching, and the resistors R1, the resistor R2 and the resistor R3 are all high-power resistors for isolation.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] The improvement of the Wilkinson power combiner circuit retains the advantages of the Wilkinson power combiner, such as good port matching, high input port isolation, multi-stage cascading to expand bandwidth, and low cost; at the same time, the coaxial transmission cable is used to solve the problems of low transmission and synthesis power of the Wilkinson combiner, large PCB board area, high material and process requirements, strong signal mutual coupling, interference, etc.; the high-power isolation resistor distributed capacitor, high-resistance coaxial cable and port matching fan-shaped line capacitor are used to form a Chebyshev low-pass filter, which shortens the length of the coaxial cable and reduces the loss, and makes the combiner have stopband suppression and low-pass filtering effects; the microstrip circuit fan-shaped line capacitor is designed to increase the heat dissipation area, The thermal resistance is reduced, the synthesizer can withstand greater power, the capacitor can withstand high voltage and high power, and it is completed with the PCB plate making, without additional cost. It has the same port isolation, synthesis and transmission loss as the low-power Wilkinson synthesizer, similar bandwidth, and also has the effects of transmitting high power, synthesizing high power, stopband suppression and low-pass filter. A certain type of synthesizer designed uses a three-stage cascade circuit, frequency: 0.2-0.46Hz; transmission loss: <0.15dB; port VSWR: <1.15; input port isolation: >30dB; synthesis rated power: 200W; power division transmission power: 600W, meeting the requirements of light weight, good reliability and design, with little additional cost;

[0012] The invention has a simple structure and is easy to manufacture. The circuit has better performance, greater power, flexible wiring, simple processing, and greatly improved reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic circuit diagram of a single-stage power combiner of a high-power combiner that combines a microstrip circuit and a coaxial line proposed by the present invention;

[0014] Figure 2 The present invention provides a circuit diagram of a high-power synthesizer that combines a microstrip circuit with a coaxial line. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0016] Reference Figure 1-2 , a high-power synthesizer mixed with a microstrip circuit and a coaxial cable, comprising an input impedance Z0, one end of the input impedance Z0 is connected to one end of a fan-out capacitor X3, the impedance Z0 is simultaneously connected to one end of two quarter-wavelength coaxial cables Z1, the other ends of the two quarter-wavelength coaxial cables Z1 are connected to the fan-out capacitor X1, one end of the quarter-wavelength coaxial cable Z2 and one end of a branch microstrip line Z1, the other ends of the two branch microstrip lines Z1 are connected to an isolation resistor R1, the other ends of the two quarter-wavelength coaxial cables Z2 are connected to the fan-out capacitor X2, one end of the quarter-wavelength microstrip line Z3 and one end of the branch cable Z2, the other ends of the two branch microstrip lines Z2 are connected to an isolation resistor R2, the other ends of the two quarter-wavelength microstrip lines Z3 are connected to one end of a branch output impedance Z0 and one end of the branch microstrip line Z3, the other ends of the two branch microstrip lines Z3 are connected to an isolation resistor R3, by using a coaxial line with similar impedance to replace a λ / 4 high-resistance microstrip transmission line, in order to reduce the length of the coaxial line, capacitor matching is added at both ends of the coaxial line at the same time. The invention has the advantages of simple structure, convenient manufacture, better index, higher power, flexible routing and simple processing, greatly improved reliability, microstrip line and coaxial line hybrid circuit high-power synthesizer design method, comprehensive application of multiple impedance low-loss coaxial lines, reduced transmission loss, reduced mutual coupling, strong anti-interference, innovative application of fan-shaped line capacitors for impedance matching at both ends of a quarter-wavelength coaxial line, fan-shaped line capacitors and power resistor distributed capacitors, so that the band has stop-band suppression and low-pass filtering characteristics, microstrip circuit fan-shaped line capacitors, with the completion of plate making, high voltage resistance, high power, coaxial line space routing skills, reduced circuit board area, isolation resistors and coaxial line low thermal resistance and high power design application, improved transmission power, synthetic rated power of 200 watts, centimeter maximum power of 600 watts.

[0017] In the present invention, the quarter-wavelength coaxial cable Z1 is a low-loss 100Ω impedance 1 / 4 wavelength coaxial cable line, the quarter-wavelength coaxial cable Z2 is a low-loss 75Ω impedance 1 / 4 wavelength coaxial cable line, the quarter-wavelength microstrip line Z3 is a 1 / 4 wavelength, 55Ω impedance microstrip line, the capacitor X1, the capacitor X2 and the capacitor X3 are all fan-shaped line capacitors for impedance matching, the resistors R1, the resistor R2 and the resistor R3 are all high-power resistors for isolation, and the coaxial line with similar impedance is adopted to replace the λ / 4 high-resistance microstrip transmission line, in order to reduce the length of the coaxial line, at both ends of the coaxial line, capacitor matching is added, the transmission loss is reduced, the heat dissipation is better, the power bearing capacity is improved, the mutual coupling is reduced, the matching capacitor and the power resistor distributed capacitor, so that the out-of-band has stopband suppression and low-pass filtering characteristics, the coaxial line has small spatial radiation and less coupling, the isolation is improved, and the signal integrity can be guaranteed; the present invention has a simple structure and is easy to manufacture, the circuit has better performance, higher power, flexible routing and simple processing, and the reliability is greatly improved

[0018] The working principle of the present invention is as follows: by using a coaxial line with similar impedance to replace a λ / 4 high-resistance microstrip transmission line, in order to reduce the length of the coaxial line, capacitor matching is added at both ends of the coaxial line at the same time, transmission loss is reduced, heat dissipation is better, power bearing capacity is improved, mutual coupling is reduced, matching capacitors and power resistor distributed capacitors are made, so that there is stopband suppression and low-pass filtering characteristics outside the band, the coaxial line has small spatial radiation and less coupling, isolation is improved, and signal integrity can be guaranteed; the present invention has a simple structure and is easy to manufacture, the circuit has better indicators, higher power, flexible routing and simple processing, and reliability is greatly improved, and the number of synthesizers can be selected according to the working frequency, bandwidth and power of the synthesizer (power divider); the corresponding impedance coaxial cable and isolation resistor are selected, and the design principle is applicable to broadband and ultra-wideband, port high isolation and high power applications.

[0019] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-power synthesizer of a microstrip circuit and a coaxial cable, comprising an input impedance Z0, characterized in that: One end of the input impedance Z0 is connected to one end of the fan-out capacitor X3, the impedance Z0 is simultaneously connected to one end of two quarter-wavelength coaxial cables Z1, the other ends of the two quarter-wavelength coaxial cables Z1 are connected to the fan-out capacitor X1, one end of the quarter-wavelength coaxial cable Z2 and one end of the branch microstrip line Z1, the other ends of the two branch microstrip lines Z1 are connected to the isolation resistor R1, the other ends of the two quarter-wavelength coaxial cables Z2 are connected to the fan-out capacitor X2, one end of the quarter-wavelength microstrip line Z3 and one end of the branch microstrip line Z2, the other ends of the two branch microstrip lines Z2 are connected to the isolation resistor R2, the other ends of the two quarter-wavelength microstrip lines Z3 are connected to one end of the branch output impedance Z0 and one end of the branch microstrip line Z3, and the other ends of the two branch microstrip lines Z3 are connected to the isolation resistor R3; The quarter-wavelength coaxial cable Z1 is a low-loss 100Ω impedance 1 / 4-wavelength coaxial cable; The quarter-wavelength coaxial cable Z2 is a low-loss 75Ω impedance 1 / 4-wavelength coaxial cable.

2. A high-power synthesizer combining a microstrip circuit and a coaxial cable according to claim 1, characterized in that: The quarter-wavelength microstrip line Z3 is a 1 / 4 wavelength, 55Ω impedance microstrip line.

3. A high-power synthesizer combining a microstrip circuit and a coaxial cable according to claim 1, characterized in that: The capacitor X1, the capacitor X2 and the capacitor X3 are all fan-shaped line capacitors for impedance matching, and the resistors R1, the resistor R2 and the resistor R3 are all high-power resistors for isolation.

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