Monolithic waveguide zinc-oxide-on-silicon convolver

A monolithic waveguide zinc-oxide-on-silicon convolver has been constructed and operated at a centre frequency of 125 MHz. The zinc oxide is originally deposited over the whole substrate and then etched to form the waveguide. The waveguide width is 1/10 of the beam width at the input transducers, which should yield a 20 dB improvement in efficiency over a normal convolver with a beam width equal to the transducer width, after accounting for the loss in the input tapers. Such an improvement was observed in experimental devices.