Surface-acoustic-wave frequency-to-voltage converter

A frequency-to-voltage conversion technique is described by using a surface-acoustic-wave delay line with three interdigital transducers, one for input and two for output. Two output signals have a phase difference corresponding to different delay lengths, which are detected as a frequency-to-voltage converted signal via a differential amplifier. The operational principle as a discriminator is reported together with successful experimental results. This type of frequency-to-voltage converter is valid in a number of applications where high frequency is an important consideration.