A 30-48 GHz GaN Stacked Power Amplifier

This paper reports on a novel wideband 2-stacked-FET suitable for high efficiency power amplifiers working up to the Ka and U band. To prevent oscillations at high frequency while obtaining a high output power, a stacked architecture with dual parasitic inductive has been proposed. Utilizing a 100 nm HEMT technology when biased with a drain voltage (VDS) of 24 V, this GaN power cell exhibits a small signal gain (S21) of 14 dB based on a quiescent current (IDQ) of 180 mA, all while maintaining unconditional stability. It is concluded that the maximum output power of 32 dBm is obtained with the peak power added efficiency of 48% when input power is 23 dBm at the frequency of 38 GHz. Meanwhile, with the output return loss (S22) better than -8.5 dB, the input return loss (S11) can be about -5 dB. Aa a result, the 3 dB bandwidth is about 30–48 GHz.