High Performance C-band Power Amplifier for CW and Pulsed Applications

This paper demonstrates design, fabrication and measurements of GaN-HEMT based power amplifier (PA) for pulsed radar applications. The purpose of this effort is to design and develop a class- AB PA using GaN HEMT device to get the wide dynamic range upto 80dB (i.e., -50 to 30dBm) in a compact size for C-band pulsed applications. It can also be employed as a driver and power stage for C- band applications with pulse modulation requirement upto 40 dBm. In PA design, oscillations are common which caused the unwanted high gain at the lower frequencies. To avoid this scenario, capacitor bank is used at the bias. Impedance transformers both at the input and output of the amplifier are implemented to achieve optimized parameters such as high RF power, high power gain and good input/output return losses etc. The proposed amplifier is fabricated and then characterized to verify the design parameters successfully. It has been observed that the simulated results are in good agreement with the measured readings. Maximum RF pulsed power output of 10W (40dBm), power gain of 12dB and dynamic range of 80dB are demonstrated for C-band applications.