High gain wide band acoustic surface wave transducers using parametric upconversion

Claim 1

An acoustic surface wave parametric upconverter transducer comprising: a. an elastically nonlinear substrate for supporting acoustic surface waves; b. a plurality of N interleaved conductive fingers formed on said substrate, alternate ones of said fingers being interconnected for producing a first acoustic surface wave having a first center frequency; c. a plurality of n interleaved conductive fingers formed on said substrate in a position along the path of acoustic surface wave propagation initiated by said plurality of N interleaved conductive fingers, where n N, for producing a second acoustic surface wave having a second center frequency, whereby there is produced on said substrate a third acoustic surface wave at a frequency equal to the sum of the frequencies of said first and second acoustic surface waves; and d. output transducer means responsive to said third acoustic surface wave at a point where the energy of said second acoustic surface wave has been substantially completely transferred to said third acoustic surface wave for converting said third acoustic surface wave into an electromagnetic wave, said output transducer means comprising a coherent light source for directing a beam of light on to said common substrate and means responsive to said beam of light after it has impinged said substrate for receiving said light and converting it into an output electrical signal.