Low loss and high stopband rejection switchable SAW filter bank

The design and testing of low loss, high stopband rejection 16 channel switchable SAW filter bank using ST quartz as substrate is described. In order to decrease the insertion loss, the individual filters used for bank consisted of SPUDT with the insertion loss of less than 6 dB. Both input and output switches are used instead of input interconnection network and output switch to decrease the insertion loss of input interconnection network. The cascade-connected two stages are constructed to increase the stopband rejection. An amplifier is put between two stages to compensate loss of signal-to-noise. The experimental filter bank results in insertion loss of less than 13.5dB(include the insertion loss of four-stage switch), stopband rejection of more than 70 dB.