8 channel and 32 channel low loss switchable SAW filter banks

The design and testing of 8 channels and 32 channels low loss switchable SAW filter bank is described. Both input and output switches are used instead of input interconnection network and output switch to decrease the insertion loss of input interconnection network. In order to decrease the insertion loss, the individual filters used in 8 channels filter bank consists of longitudinally-coupled DMS filter on 64/spl deg/Y-X LiNbO/sub 3/ with the insertion of less than 2 dB. The experimental 8 channels filter bank results in insertion loss of less than 3 dB (include the insertion loss of two-stage switch), stopband rejection of more than 50 dB. In 32 channels filter bank, the individual filter consists of slanted-finger interdigital transducer (SIDT) including EWC/SPUDT on 128/spl deg/Y-X LiNbO/sub 3/ with the insertion loss of less than 10 dB. The experimental 32 channels filter bank results in insertion loss of less than 15dB (include the insertion loss of two-stage switch), volume less than 150cm/sup 3/.