400 mhz saw if filter for satellite broadcast receiver without any adjustments

A UHF SAW filter for satellite broadcast receivers has been developed. Features are high center frequency to suppress the image interference, sufficiently flat group delay for linear FM detection and unnecessary any adjustments for tuning. The influence of electrode resistance on the insertion loss, and the triple transit echo caused by wave reflection is investigated in extended Smith’s equivalent circuit model, and is effectively applied as an independent design parameter of the radiation and the load conductance. In cosequence the interdigital transducers with the wide aperture stretched nonoverlapped electrodes are efficiently verified to suppress undesired surface wave diffraction and reflection effects without any increase in the insertion loss, and to be able to omit the conventional tuning coils and the intentional impedance mismatching.