“Distortion-Free” Varactor Diode Topologies for RF Adaptivity

Abstract

Varactor diode-based circuit topologies, which can act as high-Q “distortion-free” tunable capacitive elements, are presented. These diodes are implemented in a novel ultra low-loss silicon-on-glass technology, with resulting measured Q's of over 200 at 2 GHz. The measured IM3 improvement compared to traditional single varactor tuning techniques is greater than 30 dB.