Oscillator circuit configuration for quartz-crystal-resonator sensors subject to heavy acoustic load
An oscillator circuit configuration is presented to track accurately the resonant frequency and to increase the operating range of quartz-crystal-resonator sensors subject to heavy acoustic loading. The circuit is based on a block for the active cancellation of the crystal electrical capacitance, inserted in a phaselocked loop oscillator. Experimental results confirming the successful application of the principle are reported.
