Surface-acoustic-wave devices for the 2.5–5 GHz frequency range based on longitudinal leaky waves

The recently discovered ‘‘longitudinal leaky’’ surface acoustic wave on YZ-cut lithium niobate has been used to implement low-loss bandpass filters operating in the 2.5-GHz Bluetooth frequency range. The filter is of the ladder type, employing synchronous resonators as building blocks. Resonator Q-values above 300 have been measured. The filter features a center frequency of 2491 MHz, a minimum insertion loss of 3.5 dB, and a fractional 3-dB bandwidth as wide as 6.2%. © 2003 American Institute of Physics. DOI: 10.1063/1.1573361