Research And Design Of The GaAs Microwave Monolithic Integrated Power Amplifier Circuit

Both in the field of military or civilian areas, microwave monolithic integrated circuit(MMIC) has a strong attraction. With the characteristics of small compact, anti-interference ability, good stability, low cost mass production, etc, MMIC meet the demand for modern communication systems. Microwave power amplifier(PA) is an important part of the active phased array radar T/R module. X-band electromagnetic wave length, the reflectivity strong, so the radar applied in this band have great practical value in the military. High-power amplifier(HPA) always been the key and difficult research in the study of MMIC PA. The achievement of HPA usually use power synthesis methods, the output power mostly above 5W. Currently, the shortcomings of the X-band power amplifier are the less gain of single transistors, small output power, low efficiency, etc, the single transistor’s performance restricts the performance of HPA.Through the in-depth study and research on microwave PA and field effect transistor modeling techniques, combined with literature data, we proposed some design specifications of the microwave monolithic integrated power amplifier circuit. Designed a single-transistor monolithic driver PA circuit which can be used as 5 W microwave HPA’ s driver stage. The goals are achieved to be high efficiency, low cost, high reliability, high output capability.The paper applied Taiwan WIN Semiconductors 0.25 um GaAs PHEMT process line model to complete the PA circuit design, using ADS to simulate and verify. The key technologies include the choice of device, bias circuit, load-pull technique, match circuit, etc. The PA circuit worked within 8-12 GHz, the gian up to 10 dB, fluctuation less than 2dB, P1 dB is about 29 dBm, PAE is 38%, the input and output VSWR less than 2.5. When the two-tone output power is 25 dBm, IMD3 is less than-30 dBc. The achieved indexes of PA meet the expectations. The efficiency, linearity, gain were good, and the single-transistor match reduced the size, the power consumption, the cost and improved reliability. The achievement of 29 dBm output power laying a foundation for the subsequent research on HPA, the research results own certain theoretical and practical value.