Full-Wave Phase-Switched Impedance Modulation Actuator for Tunable Matching Networks

Accurate, rapid, and dynamically-controlled impedance matching is critical for many radio-frequency (RF) power applications. This work presents a solid-state electronically-variable reactance (eVX) actuator capable of continuous tuning with response times on the order of a single RF cycle. The actuator is based on Phase-Switched Impedance Modulation (PSIM), which switches passive elements at the RF frequency to modulate their impedances. Prior PSIM-based implementations have demonstrated the feasibility of fast, solid-state tunable matching networks (TMNs) for high-frequency applications at kilowatt power levels. This work introduces a full-wave PSIM architecture based on a differential push-pull topology, significantly reducing switching harmonics, enhancing power handling, and improving design flexibility. This architecture is employed in the design of a 13.56 MHz eVX actuator targeting -5 Ω to -15 Ω capacitive reactance modulation range and its performance is demonstrated in a 13.56 MHz, 3.5 kW TMN for RF plasma applications, achieving microsecond tune times.