A High Power GaN MMIC 36.5 Watt X Band Power Amplifier

Abstract

This work presents the design of a high power amplifier circuit for the X band application having frequency of operation from 9.75 GHz to 11 GHz. Operating frequency range has been selected according to the input return loss (|S(1, 1)|) and output return loss (|S(2, 2)|) value and it is always larger than 12 dB for this work. In addition, insertion loss |S(1, 2)| is always larger than 29.41 dB for worst case condition. In case of X band application this architecture can be widely used for the bandwidth of 1.25 GHz and it achieves 36.5 watt output power with input 1dB compression point (P 1 dB) of 29 dBm. Also, it shows the power added efficiency (PAE) of 35% and this architecture has been implemented with one driver amplifier (DA), four high power amplifiers (HPAs) and six Wilkinson power divider and or combiner circuits. Power combiners and dividers circuit’s loss have been adjusted with the gain path of the one DA and HPA circuit for improving the linearity of the overall PA circuit. Proper impedance matching has been done for the input-output and intermediate stage of the power amplifier circuit with the help of smith-chart utility in advanced design system (ADS) tool in Keysight. Maximum power gain in dB of the power amplifier circuit is 17. According to our knowledge this work shows a new state of the art performances for this power amplifier. OIP 3 and IIP 3 of the power amplifier for the input power of 20 dBm are 55.063 dBm and 39.197 dBm, respectively. All design components of the PA circuit have been carried out in UMS 0.25 µm GaN HEMT process.