Over 10-MHz bandwidth envelope-tracking DC/DC converter for flexible high power GaN amplifiers

Summary form only given, as follows. The paper describes a fast envelope-tracking circuit capable of 10 MHz (up to 17.5 MHz) bandwidth based on RF GaN devices and 50 MHz switching frequency. The efficiency of the VHF converter is up to 90%, comparable to a conventional DC/DC converter. A demonstrator has been built and mated with a RF GaN HEMT output stage. The C/I for 10–12 W RF output power near saturation shows linearity improvement of 5–8 dB and an efficiency improvement of up to 8% when compared to no tracking circuit.