Use of Three-IDT SAW Devices in High-Definition Satellite TV Receivers

Abstract

Abstruct-Wo subunits have been developed successfully for a highdefinition satellite TV receiver system using three interdigital transducer (IDT) SAW devices. One is a filter subunit and the other is a linear frequency discriminator. The filter subunit is composed of two SAW filters that separate luminance and chrominance signals into Y and C channels. One SAW filter has realized insertion loss of 13 dB at a center frequency of 430 MHz and a large triple transit echo WE) suppression of more than 45 dB over a wide frequency bandwidth of 80 MHz. The frequency discriminator is composed of two SAW delay lines. It demodulates the luminance and chrominance FM signals with discrimination linearity of better than 1 percent. These SAW devices have yielded a linear phase system of small size without a complex tuning process. These were incorporated into high definition satellite TV receivers and realized high performance, differential gain (DG) of less than four percent and differential phase (DP) of less than 2.1 degrees.