IIDT-type low-loss SAW filters used in wideband cellular radio systems

The design and performance of wideband low-loss surface-acoustic-wave (SAW) filters employing interdigitated interdigital transducers (IIDTs) suitable for cellular radio systems are described. The filters were fabricated on 36/spl deg/ YX-LiTaO/sub 3/ substrates. A detailed design method which optimizes the IIDT configuration has been worked out. In the 500-MHz band, fractional bandwidths of up to 5.2% with passband ripples smaller than 1 dB were attained. Insertion loss and sidelobe suppression were at 1.8 dB and 23 dB, respectively.<
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