0.5W S-band two-stage power amplifier: Research, design and implementation

This paper describes the study of designing a power amplifier (PA) operating at S-band which amplifies a low power radio frequency (RF) signals into a higher power signals. The RF transistor BFP740 and GaAs FET MGF2430A are used in this work. The PA includes two stages which have both driver and power stages. The two-stage PA with the bandwidth of 400 MHz at 2.9 GHz center frequency is designed to have the desired specifications. In the designed two-stage PA, the forward gain is over 25 dB and power-added efficiency (PAE) is rather than 20% of combining driver and power stages. Besides, the output power obtains 27 dBm in total. The input/output coefficient reflections are less than −10 dB.