PHASE SHIFTER FOR SURFACE WAVE

摘要

PURPOSE:To keep constant the phase differece of the output of two output transducers over wide regions, by weighting the reed screen type electrodes constituting one output transducer among two sinusoidally. CONSTITUTION:The piezoelectric substrate 1 is provided with an input transducer 3 almost at the center and output transducers 2 and 4 by clipping them. The transducer 3 is formed with reed screen electrodes constituted as interdigital for the comblike electrodes of a pair. The transducer 2 is the reed screen type electrodes in which a pair of comblike electrodes interdigitally constitutes the electrode fingers and the width of overlap of the electrode fingers is equal. The transducer 4 is the electrodes in which a pair of comblike electrodes different from the length of adjacent electrode fingers are constituted so that the electrode fingers oppose each other and the envelope of overlap of the electrode fingers is sinusoidal interdigitally and weighting is given to the fingers.