1.03 GHz operation of a low-loss SAW filter using 3-phase unidirectional transducers with thin dielectric layered feed electrodes

Successful working of a 3-phase unidirectional transducer (TPUDT) SAW filter at 1.03 GHz, without using any airgap crossovers, is reported in the letter. A thin-film capacitance existing between the feed electrodes of the transducers is used to advantage, as an essential element of the required phaseshifting network. The minimum insertion loss is found to be 2.0 dB. The filter is believed to have wide applications in the present and future communication systems requiring low-loss bandpass filtering.