Patent ID: 8143955

Claim:
An oscillator circuit comprising: a first oscillator in an open loop configuration that generates a signal having a first frequency; a second oscillator that generates a signal having a second frequency; a mixer coupled to the first oscillator and the second oscillator, and responsive to the signal having the first frequency and the signal having the second frequency to provide a signal having a third frequency and one or more frequency components; a filter coupled to the mixer, and responsive to the signal from the mixer to attenuate the one or more frequency components and provide a signal having a desired frequency; a correction circuit coupled to the second oscillator and the filter to correct a drift in at least one of the first frequency and the second frequency by controlling the second frequency, thereby correcting the drift in the third frequency and the desired frequency; and a switching circuit coupled to the correction circuit for enabling the correction circuit to correct the drift in the frequency of the output signal.