An oscillator providing predictable oscillator modulation sensitivity includes an amplifier and a feedback circuit disposed about the amplifier. The feedback circuit includes a resonator having a first port and a second port and a voltage-controlled phase shifter having an input port, an output port and a control port, the input port of the voltage-controlled phase shifter connected to the output port of the amplifier and the output port of the voltage-controlled phase shifter coupled to a port of the resonator. The oscillator further includes a circuit, responsive to signals from the output of the voltage-controlled phase shifter and the first port of the resonator, to provide a control signal to the control port of the voltage-controlled phase shifter for degenerating low frequency FM noise arising within the amplifier.