Ultra wide bandwidth, low loss bulk acoustic delay lines

This article describes the progress we have made in the design and fabrication of LiNbO₃-spinel bulk acoustic delay lines (1,2). We have fabricated a single-ended delay line an line with an instantaneous bandwidth (untuned) from 2 to 15 GHz. For lower frequency and narrower bandwidth applications, a total loss of 16 dB has been achieved with 2 dB bandwidth from 1.3 to 2.1 GHz for 1 μsec delay. Online, computer controlled monitoring of transducer thickness had been incorporated into the fabrication process. Computer aided techniques were used in impedance matching network design.