GaN broadband Power Amplifiers for terrestrial and space transmitters

This contribution reports several Power Amplifiers (PAs) designed using both GaN-on-Si and GaN-on-SiC technologies provided by Selex-SI foundry. The former is still under development while the other one is more stable and under space qualification procedure. Thus, in order to give a comprehensive evaluation of both technologies, two PAs were developed in hybrid form for Ultra Wide Band (UWB) terrestrial applications using GaN-on-Si HEMT devices, and another one was developed in monolithic form for space transmitter using the GaN-on-SiC technology. About the hybrid PAs, two different active device peripheries were selected. The first one was a 10×100 μm gate periphery named P10D and the second one was a 12×200 μm gate periphery named P12G. The amplifiers were designed in a single ended configuration using the source/load-pull and Scattering parameters measured data. From the expected performances, the PA built with P10D has an operative bandwidth from 1 GHz to 7 GHz with a saturated output power higher than 37 dBm while the other one has an operative bandwidth from 1 GHz to 6 GHz with a saturated output power around 41 dBm. Instead, the HPA designed using GaN-on-SiC technology, represents the first step towards the realization of a fully integrated GaN transmitter for X-Band space applications. In this case, experimental results shown that the HPA reaches an output power higher than 41 dBm with a gain higher than 17 dBm and a ripple lower than 0.5 dB from 8.6 GHz to 10.6 GHz frequency range in a chip area lower than 10 mm².