SOI CMOS tunable capacitors for RF antenna aperture tuning

Abstract

This paper provides a detailed analysis of a SOI CMOS tunable capacitor for antenna tuning. Design expressions for a switched capacitor network are given and quality factor of the whole network is expressed as a function of design parameters. Application to antenna aperture tuning is described by combining a 130 nm SOI CMOS tunable capacitor with a printed notch antenna. The proposed tunable multiband antenna can be tuned from 420 MHz to 790 MHz, with an associated radiation efficiency in the 33-73% range.