Frequency synthesiser employing a bulk-acoustic-wave delay line

When a broadband s.a.w. delay line is used as the feedback element of an amplifier, one has an oscillator capable of operation at a comb of frequencies. This letter discusses some advantages of replacing the s.a.w. delay line by a conventional bulk-acoustic-wave delay line, and describes two techniques by which the frequency can be programmed reliably across the comb.