P-band GaN High Power Amplifiers for space-borne radar applications

This work discusses the development of P-band GaN High Power Amplifiers with target RF output power values higher than 140 W and power added efficiencies (PAE) beyond 70 %. Two realizations of an 80 W class single-ended power module have been designed, manufactured and tested using GaN devices from two different suppliers. Rigorous stability analyses based on pole-zero identification techniques have been performed from early conceptual stages in both linear and nonlinear regimes. In parallel, traditional load-pull techniques have been used in both designs to achieve the best trade-off in terms of RF output power, PAE and stability. In order to achieve the required RF output power, two identical power modules have been combined in a balanced architecture, obtaining RF output power levels in excess of 180 Watts with drain efficiency levels of 65 % by means of test. The HPAs have been characterized over temperature from -15 °C to 55 °C, showing negligible drifts.