Tapered transducers-design and applications

The tapered transducer was first demonstrated over 25 years ago but until recently has seen little commercial use. This paper reviews the theory that describes how the wideband response of a tapered transducer is achieved by the summation of narrow-band channels. In addition, it discusses weighting techniques appropriate to tapered transducers including block weighting, and how the use of SPUDT electrode structures allows the same reduction in IL and triple-transit over a wide bandwidth normally achieved only with relatively narrow-band filters. Experimental results are presented along with a discussion of applications that benefit from the unique properties of tapered transducers such as a single-bounce dispersive delay line, a multi-tap delay line with low spurious reflections, a channelizer or filter bank, an AO Bragg cell, and a radar pulse compression system without range/velocity ambiguity in the presence of Doppler