A wide band, low phase noise, differential YIG Tuned Oscillator

Abstract

YIG Tuned Oscillators (YTO) offer an unbeatable combination of broad band electronic tuning and extremely low phase noise. However traditional YTO designs require significant highly skilled and expensive alignment labor. Differential YTOs (DYTOs) minimizes bandwidth limiting parasitic effects and require no RF grounds. Additionally, only the phase dispersive active devices limit electronic tuning bandwidth. DYTOs are extremely simple circuits consists of three BJT active devices, a YIG sphere, and two coupling loops. The extra wide bandwidth non-dispersive phase shift required to fulfill start oscillation conditions is provided by simply reversing the sense of the YIG sphere's coupling loops. DYTOs may be easily adapted to IC various technologies. Hybrid prototype bandwidths exceeding one decade (2 GHz to 20 GHz) are demonstrated with extremely low phase noise of −150 dBc per Hz at a 1 MHz offset.