A 250 nm CMOS / LDMOS Pulse-Width Modulator and Driver for space-borne GaN switch mode power amplifiers in P-band

Abstract

In this paper, the design of a single-chip RF Pulse-Width Modulator and Driver (PWMD) aimed at exciting a 80 W class-E GaN high-power stage at 435 MHz is described. For the required buffer size, avoiding potential ringing of the pulses within the buffer structure presents a major challenge in the design process. Therefore, a smaller chip capable of driving capacitive loads of up to 5 pF was initially designed, fabricated and tested. An approach based on 3D EM simulations was used to validate the test results. Based on the presented results, an enlarged chip able to drive a 80 W GaN high-power stage is currently being designed.