| Abstract: | An electro-acoustic device includes a plurality of suspended,
piezoelectric, acoustically waveguiding membranes supported in a common
plane. An input transducer coupled to one of the waveguiding membranes
converts input electrical signals to traveling-wave acoustic signals. An
output transducer coupled to one of the waveguiding membranes converts
acoustic signals to electrical signals. At least two of the waveguiding
membrane have parallel straight sections that are longer than a guided
acoustic wavelength and that are mutually separated by an air gap having
a width less than the guided acoustic wavelength. |