A GaN-based supply modulator for energy efficiency enhancement of active phased-array antennas

This paper presents the design of a GaN HEMT based boost DC/DC converter and a dynamic supply modulator suitable for DC to RF power conversion improvements in RF transmitters. This work addresses a contribution to energy efficiency enhancements of active phased-array antennas. A main aspect reported here concerns a circuit implementation of a boost converter and its specific gate driver in GaN technology. A supply modulator has been built and connected to the drain bias port of a 8W S-Band RF power amplifier. Large signal pulsed RF measurements are given to validate the study and demonstrate that about 10% efficiency improvement is obtained.