SURFACE ACOUSTIC-WAVE SLANTED DEVICE TECHNOLOGY

The most common linear FM chirp surface acoustic wave devices used in radar employ the conventional in-line structure for the transducer. These devices have Fresnel ripple and interelectrode reflections in the time domain that, unless compensated for, will degrade the compressed pulse time sidelobes. Reported in this paper are techniques for constructing slanted transducers and slanted reflective arrays that minimize interelectrode reflections and Fresnel ripple. Utilizing the slanted transducer structure, flat power response has been achieved for both wide-band lithium niobate devices and narrower band quartz devices. Weighting of the slanted transducers is also easily achieved and a pulse compression matched pair of the devices on lithium niobate has produced time sidelobes of -37 dB. The equivalent circuit model for lithium niobate and quartz slanted transducers is presented and equations for the beamwidth design are derived. The design of slanted reflective array correlators is presented along with some test results of the first device. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.