A fully-integrated S/C band transmitter in 45nm CMOS/ 0.2gm GaN heterogeneous technology

A fully-integrated transmitter is presented in DARPA's DAHI process technology, featuring heterogeneous integration of 45nm SOI CMOS and 0.2pm GaN technologies. This transmitter is capable of transmitting SOQPSK-TG telemetry waveforms across 2-5 GHz with a peak transmitter power efficiency of 41.32% and peak output power of 32.93 dBm. A reconfigurable CMOS phase modulator is implemented to provide 6-bit phase resolution across the entire output frequency range, and a wide-swing CMOS buffer was designed to drive the GaN power amplifier. The GaN PA features a three-stage design, featuring a differential CML buffer, push-pull inverting buffer, and a class-E switch-mode power amplifier to efficiently amplify the signal. To the authors' knowledge, this is the first fully-integrated transmitter combining CMOS and GaN technology demonstrated in literature.