ACOUSTIC SURFACE WAVE DEVICE INCLUDING A REFLECTIVE MULTISTRIP COUPLER

摘要

An acoustic wave device comprising a piezoelectric substrate on which are provided an input transducer (2), an output transducer (4) and a compact reflective multistrip coupler (6) of the kind in which the strips of each pair of comparatively widely spaced strips (7 or 8) in a one array of mutually parallel strips are connected to respective strips of a pair of comparatively narrowly spaced strips (8 or 7) in the other array, and in which the wide and narrow spacings alternate along each array. The improvement provides further electrodes 9 which are located in the relatively wide spaces in each array and are electrically interconnected 20 so as to effect a transfer of signal currents along each array and from one array to the other. The object is to improve efficiency, reduce insertion loss and improve the shape of the pass band.