Radiation resistance measurements have been made on 20 electrode pair interdigital transducers deposited on poled crystals of lithium niobate, for a variety of cuts and propagation directions, with the objective of determining optimum geometries for the efficient wideband generation of acoustic Rayleigh waves. UsingYcut,Zaxis propagating lithium niobate and five‐electrode pair transducers a 100‐MHz delay line has been constructed with an insertion loss of 11.5 dB at a delay of 8.9 &mgr;sec, and a −3‐dB bandwidth of 24 MHz.