Ladder-type SAW filters using thinned density of randomly distributed "hot" electrodes

A new method for the design of relatively narrowband ladder-type SAW filters is proposed. It consists of the thinning procedure and consecutive randomization of positions of the remaining transductive periods inside the IDT to suppress undesirable additional passbands. A 0.9% fractional bandwidth filter on LiTaO(3) 42°-cut was designed and manufactured using the proposed approach.