6 Watt Power Amplifier Design and Analysis For S and C Band Radar

This paper discusses the process of designing a broad-bandwidth (BBW) 6-watt power amplifier (PA) using Keysight’s Advanced Design System (ADS). This PA design makes use of a non-linear version of a gallium nitride (GaN) high electron mobility transistor (HEMT) manufactured by Wolfspeed, the CGH40006P. PA can function within a frequency range of 3.0 to 4.6 GHz, with a central frequency of 4.0 GHz. A new method called ideal matching is used to find the input and output load impedance, along with a load-pull analysis. This helps the designed PA achieve a power added and drain efficiency of better than 50% over the frequency range of 3 to 4.6 GHz, with an output power of more than 37.78 dBm and a large signal gain (LSG) of 6 dB. The input and output matching networks have all been realised using Roger’s 4350B substrate. This PA input and output matching network has been designed with the novel approach of keeping Q value less than unity in the Smith chart utility tool available in ADS, so that the designed PA achieves a fractional bandwidth of 40%. The main use of this PA is for the radars, which can operate in the S and C band frequency ranges.