Abstract :
The varactor diode, due to its voltage dependent capacity, exhibits a nonlinearity in impedance with changes in RF power level. This change in impedance is sufficient to provide switching action. In addition to this switching action, the varactor junction has an erg burn out level on the order of a thousand times that of a mixer diode. Because of these two properties, the varactor is very applicable in solid state duplexers and limiters for mixer diode protection.
