CMOS Silicon-on-Sapphire RF Tunable Matching Networks

Abstract

This paper describes the design and optimization of an RF tunable network capable of matching highly mismatched loads to 50 Ω at 1.9 GHz. Tuning was achieved using switched capacitors with low-loss, single-transistor switches. Simulations show that the performance of the matching network depends strongly on the switch performances and on the inductor losses. A 0.5 μ m silicon-on-sapphire (SOS) CMOS technology was chosen for network implementation because of the relatively high-quality monolithic inductors achievable in the process. The matching network provides very good matching for inductive loads, and acceptable matching for highly capacitive loads. A 1 dB compression point greater than +15 dBm was obtained for a wide range of load impedances.