Microwave Power Amplifier Research And Design

Microwave power amplifier is one of the important components of the transmitter link in modern wireless communication systems. They are used widely in satellite communications, radar, electronic countermeasures, telemetry, radio astronomy, microwave communications and digital television, etc. The status of microwave power amplifier is important. So, the research on microwave power amplifier technology is valuable.Impedance, power and frequency are the three aspects of the core issues to resolve in the microwave power amplifier design process. In the aspect of impedance, the circuit simulation software Agilent ADS is used for simulating the s parameters. Based on the discussion of the lumped parameter and distributed parameter matching network, a microstrip broadband matching network was designed in this paper. Within the frequency range 2GHz~3.4GHz, the matching network has achieved the maximum gain match of the transistor CGH40010, and its gain flatness <±0.4dB. In the field of power, based on the theories of power divider / combiner, a four-way 0°power divider with high isolation and low insertion loss and an eight-way radial waveguide power combiner with high power capacity were designed. Within the frequency range 2015MHz~2130MHz, the insertion loss of the power combiner≤0.4dB and the power capacity of the power combiner>1600W. In the field of frequency, be enlightened by an S-band cavity filter's design process, a new method of how to rapid design coaxial cavity filter was introduced in this paper. Besides, the appropriate testing methods were given.In the radio spectrum, VHF is a band between high-frequency and microwave, the circuit in this band contains characteristics of Lumped parameters and distributed parameter. So, the project of VHF band power amplifier is complicated. According to the characteristics of VHF-band circuit, a VHF broadband high-power amplifier was introduced in this paper. Within the frequency range 85MHz~250MHz, the main performances of the amplifier were: output power > 47dBm; the second-order harmonic suppression≥34dBc; the third-order harmonic suppression≥25dBc; the third-order intermodulation suppression≥27dBc; power gain≥40.8dB and gain flatness≤±0 .7dB.