SAW filters were fabricated on a 128 degree rotated Y-cut X-propagation $LiNbO_3$, Y-cut Z-propagation $LiNbO_3$, and ZnO film. Inter-digital transducer (IDT) patterns were designed by a simple delta function model. The characteristics of the filter were investigated by measuring the frequency response of input admittance and transfer function, and by comparing with Mason cross-field model. IDT is placed on the substrate by image reversal lithography and lift-off method. The center frequency is SAW velocity over IDT pattern period. In 128YX $LiNbO_3$, 134 MHz and 64.8 MHz IDT were fabricated. Insertion loss of filter is -21 dB and out of band rejection is about 15 dB. The filter performance such as out of band rejection was degraded by bulk wave interference. It can be decreased by acoustic wave absorber. As an absorber, wax on the polished surface and silver epoxy on the bottom surface were adapted. To improve the filter response, it is important to reduce bulk wave and electrostatic effect.
