Wrap-around surface-wave delay lines

Acoustic-surface-wave beams at 100 MHz have been circulated in multiple transits around the periphery of small lithiumniobate samples. A time delay of 22 ¿s per round-trip transit with propagation loss of 5.75 dB per round-trip transit has been observed. This has potential application to delay lines of very long delay using a helical path between input and output transducers, and to delay lines having lower insertion loss and triple-transit signals than conventional lines.