A prototype of tunable surface acoustic wave filter

A prototype of tunable surface acoustic wave filter has been developed. The device consists of 11 interdigital transducers paralleled in the SAW propagation path. Different SAW filter configurations are realized by selecting or combining various IDTs, resulting in the tunability of both center frequency and 3 dB bandwidth. The center frequencies of the SAW filter ranges from 126.8 MHz to 199.1 MHz while the 3 dB bandwidth range from 18.8 MHz to 58.9 MHz. Changes between different SAW filter configurations is implemented by RF switches.