| 摘要 |
PURPOSE:To minimize the loss of a filter, by extending a common bus bar of electrodes adjacent to each other and at the same time crossing the grating of a reflector for elastic display waves and increasing gradually the width of the bus bar in the grating. CONSTITUTION:A common bus bar 7 for inter-digital transducer electrodes 5 and 6 formed on a piezoelectric substrate is extended to cross the gratings of reflectors 8 and 9 provided across the electrodes 5 and 6 with no connection to these gratings. At the same time, the width of the bar 7 is increased gradually in the gratings, and a wire is bonded to the bar 7 for grounding at the part close to both sides of the grating where the width of the bar 7 is large. Thus, the ohmic loss of the bus 7 is minimized, and therefore the filter loss can also be minimized. |
