Heterodyne digital control of a high-frequency micrornechanical oscillator

In this paper we present heterodyne control as a technique for digital feedback control of a high-frequency, narrowband micromechanical oscillator In this technique, isolated and synchronized hardware downconversion and upconversion components are used in conj. unction with digital signal processing (DSP) to control the oscillator Heterodyne control offers reduced computational effort for the digital control of high-frequency, narrow band system, the reduction of noise outside the pass-band, and the generation of lock-in amplifier signals. We present heterodyne control with design criteria in the context of magnetic resonance force microscopy (MRFM) cantilever control. Finally we present experimental results of heterodyne control applied to an emulated radio-frequency microcantilever system.