An RF Choke-Less Class E Power Amplifier

An RF-choke (RFC) is a crucial but difficult-to-realize component of all Class-E power amplifiers (PAs). A Class-DE PA does not require an RFC but requires two non-overlapping clocks for its operation. This brief presents an RFC-less Class-E PA which operates with a single 50% duty-cycled clock. Analytical expressions for the switch voltages and currents in the proposed PA are derived and validated. Design equations are provided. A prototype RFC-less Class-E PA is implemented in CMOS 180 nm technology. Measurements show that the PA can deliver +21.5 dBm peak output power at 1 GHz with a system efficiency of 41.1%. The measured second and third harmonic distortions at the peak power are −46 dBc and −48.47 dBc, respectively.