Design and Large-Signal Characterization of High-Power Varactor-Based Impedance Tuners

Journal article, 2018

This paper presents a new systematic and efficient method for the design of high-power varactor-based impedance tuners. By incorporating the varactor losses and voltage handling capabilities, the method allows the impedance tuning range to be maximized and losses to be minimized under high-power operating conditions. A 2.2-GHz large-signal double-stub tuner has been designed using the proposed methodology and SiC varactor diodes. Using comprehensive large-signal measurements, a 25-W input power handling is demonstrated up to Γ max ∼ 0.8. Two-tone linearity measurements show an input third-order intercept point exceeding 50 dBm for most impedances. These results clearly demonstrate the feasibility of the proposed technique for the design of high-performance large-signal tuners.