SAW realization of TV IF filter

Abstract

A surface acoustic wave filter for color television IF section is realized to promote a domestic production. For this purpose, computer aided design programs are implemented. An optimization technique is used in synthesizing a transducer pattern to achieve an asymmetrical amplitude and a nonlinear phase characteristics. A diffraction analysis for parabolic substrates and an equivalent circuit analysis for uniform electrodes are constructed in addition to a simple analysis based on an impulse response. Then, the USA NTSC type filter is actually designed considering several second order effects, fabricated on a $128\,^\circ$ rotated Y-cut X-propagation lithium niobate wafer by an etching technique, packaged in a TO-8 case, and finally measured by a network analyzer.