Controllable Transformation Matching Networks for Efficient RF Impedance Matching

Delivery of radio-frequency (rf) power in applications such as plasma loads for semiconductor manufacturing is challenging because of the high frequencies involved (e.g., 13.56 MHz), the highly-variable and rapidly-changing load impedances, and the need for high-bandwidth control. This work introduces a new switched-mode tunable matching network (TMN), termed a controllable transformation matching network (CTMN), that can efficiently transform a widely-varying, highly-reactive load impedance into a desired input impedance with a fast achievable response speed to load variations. The CTMN employs a two-port controllable switching network that provides impedance magnitude transformation, along with a resonant tank and narrow-band frequency modulation to compensate for load reactance variations. In this paper, we evaluate the proposed architecture, derive first-order theory, and develop CTMN design guidelines. The simulation results demonstrate the operation of the proposed system to provide the desired tunable impedance matching according to the analysis.