A Direct CAD Method: Microwave Tuning Varactors´ Design and Analysis

This paper describes a direct design method for microwave tuning varactor with Schottky contact, developed to realize a small relative tuning on a parallel LC circuit with a varactor diode. The method can be applied either to design/reproduce the doping profile in the varactor structure which corresponds to a given/measured frequency-voltage characteristics, or to foresee the tuning characteristics of a VCO with a given varactor. The varactor is considered as a capacitor with series resistance. The main construction parameters of the oscillator are also derived.