DUAL BAND VOLTAGE CONTROLLED OSCILLATOR

摘要

A voltage controlled oscillator operable on two widely separated frequency bands, such as 900MHz and 1.8 GHz for example. The voltage controlled oscillator includes two negative resistance generators (32, 34) which share a common tunable tank circuit (26) and a common impedance matched combiner circuit (28) which provides the RF output (36). The VCO uses no pin diodes which could degrade Q and phase noise, and the VCO uses only one varactor (30) to tune both frequency bands which reduces costs. Separate negative resistance generators (32, 34) are used to provide optimum frequency selectivity within each frequency band.