Broad-Band Compensation for Diffraction in Surface Acoustic Wave Filters

Abstract

Absstroct-New generalized methods for broad-band diffraction compensation in surface acoustic wave filters have been developed. An improved method uses a diffraction analysis method which takes a transverse end effect into account so that it gives more accurate response. The correction methods described in this paper are classified into two groups. One is based on matching of the complex sample values of the baseband impulse response and the other is based on a least-squares algorithm. The former has an advantage that it gives a fast computation time. The latter is a more sophisticated method which enables the correction in the frequency domain as well as in the time domain. This means that the technique is particularly effective when designing for complex passband shapes, whose specifications in some parts are stricter than in others.