A power amplifier (PA) with variable gate bias is compared to an Envelope Elimination and Restoration (EER) configuration. Each use the lowfrequency envelope and high-frequency phase component of the signal. The test circuit is implemented using a discrete GaN HEMT power device. Measurements show that the EER architecture maintains a relatively high drain efficiency for a wide output power range, while the PA with variable gate bias shows a significant drop in efficiency for lower output powers.