A Continuously Tuned Varactor Array

Abstract

A MOS varactor circuit uses an array of softly switched varactors to improve the linearity of the capacitance tuning-control and reduce the dependence on RF-input signal level while increasing the useful capacitance-tuning range. Test circuits have been fabricated in both 90 nm and 0.35 mum CMOS processes and are directly compared to a conventional varactor.