C Band 50W GaN Power Amplifier MMIC with High Harmonic Rejection

This paper presents design methodology of a C band 50W GaN Power Amplifier (PA) MMIC, fabricated in GaN MMIC process. The C-Band 50W GaN PA has been designed for use in Pulsed Applications. It is a 2-stage design, with input and output matched to 50Ohms and operates at $28 \mathrm{~V}$ supply voltage. Design goals are output saturated power of $50 \mathrm{~W} \mathrm{~min}$ at the fundamental with high harmonic rejection and PAE of $40 \%$ across required bandwidth. These design goals were met by combination of Load-pull and Harmonic tuning techniques. An LC resonator network specifically implemented at the output to improve harmonic rejection and obtain efficiency. Measured results demonstrate $50 \mathrm{~W}$ min saturated Output Power, $35 \%$ PAE, $15 \mathrm{~dB}$ Power Gain and a high harmonic rejection of 45dBc. Performance has been measured upto $30 \%$ Duty Cycle for a pulse width of $1 \mathrm{~ms}$.