Voltage Controlled SAW Oscillator with Phase Shifter

摘要

An oscillator which, in one embodiment, is a voltage controlled surface acoustic wave oscillator including at least a surface acoustic wave filter and a voltage controlled phase shifter. In one embodiment, the phase shifter includes at least one low pass circuit and two high pass circuits coupled in series to improve phase shift versus control voltage linearity. In one embodiment, the low pass circuit includes at least a pair of inductors in series and a variable resistor coupled in parallel therebetween and to ground and the high pass circuit includes at least a pair of variable resistors in series and an inductor coupled in parallel therebetween and to ground.