Application of Nonlinear Interactions in Acoustic Media to Microwave Signal Processing Devices

摘要

Nonlinear interactions of surface waves in acoustic media can lead to the implementation of a number of signal processing functions. The work under the contract was directed toward the implementation of the convolution function using piezoelectric crystals, primarily lithium niobate, as the acoustic medium. The objective was to obtain broadband operation, to minimize spurious signals, to characterize the devices in this mode of operation, and to evolve a design theory for these devices. The development of suitable broadband input transducers and the design of the coupling structure were both major elements of the effort. Three devices were delivered as a result of the work; prime concentration was directed toward completion of a broadband device encompassing the frequency range of 95 to 180 MHz, with a convolution time of 15 microseconds. Narrower band devices operating at 195 MHz center frequency with a convolution time of 15 microseconds and at 146 MHz with a convolution time of 8 microseconds were also delivered. (Author)