Device characterization and modeling for the design of UHF Class-E inverters and synchronous rectifiers

In this paper, the advantages derived from an appropriate characterization and modeling of active and passive devices, leading to the optimized design of Ultra-High Frequency (UHF) Class-E inverters and synchronous rectifiers, are highlighted. While the combination of a couple of low-frequency and RF measurement techniques is shown to be valid for the extraction of a simplified model as a switch, a more complex approach may be required if also addressing the design of the continuous wave (CW) driving network or if interested in taking fully advantage of other transistor characteristics. Design examples, based on GaN HEMTs and a GaAs E-pHEMT, are presented, in which the parasitics of the employed coils and capacitors are also taken into consideration. Wireless transmitting and powering applications have been addressed.