Method for using interdigital surface wave transducer to generate unidirectionally propagating surface wave
US4575696A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1972 |
| Grant date | Mar 11, 1986 |
| Priority date | — |
| Expiry date | Aug 2, 1992 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/145
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Disclosed is a unidirectional interdigitated surface wave transducer having at least three discrete arrays of conductive elements, each array comprising, in a comb-like structure, a plurality of electrodes electrically interconnected in parallel and having a periodicity corresponding to one acoustic wavelength of the resonance frequency of the transducer. The discrete arrays of electrodes are deposited upon a piezoelectric substrate in an interleaved pattern to define an interdigitated transducer. Respective electrodes of a given array are substantially equidistantly spaced apart from electrodes of the other arrays and are electrically insulated therefrom. The arrays of electrodes are positioned upon the substrate such that there are at least three electrodes per acoustic wavelength at the resonance frequency. A voltage of different phase is simultaneously applied to each array of electrodes by means of novel broadband phase shifting circuits to generate an acoustic wave that propagates in only one direction along the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.