Highly Linear Silicon-on-Insulator CMOS Digitally Programmable Capacitor Array for Tunable Antenna Matching Circuits

A stacked-FET linear 4-bit silicon-on-insulator (SOI) CMOS switched capacitor array is designed for use in tunable antenna matching circuits. A New biasing strategy without negative bias voltage is proposed to circumvent drawbacks such as digital switching noise and harmonics feed-through to the antenna. The proposed switched capacitor array shows almost identical power handling capability to that of the conventional version with negative bias voltage. Compared to other works in SOI or silicon-on-sapphire (SOS) technologies, it shows a comparable or better quality factor, tuning range, power handling capability, and harmonic distortion while consuming ultra low power.