An acoustic surface wave phase-locked loop device

In this paper we present a new acoustic surface wave phase locked loop. This device uses the non-linear coupling characteristics of an insulating piezoelectric to an adjacent semiconductor to generate an electric field in the semiconductor. The low-frequency voltage resulting from the spatial integration of the electric field along the semiconductor is used as the controlling voltage of a voltage controlled oscillator. The above device acts as a phase locked loop of either the first order Or the second order, depending on the amplitude of the input waves, the characteristics of the coupling device and the integration length of the electric field in the semiconductor. Both theoretical calculation and experiments in determining the lock range, bandwidth, frequency tracking, and FM demodulation are described.