| 摘要 |
PURPOSE:To reduce the loss of a filter and to facilitate the connection to an electrode lead, by increasing the width of a common bus bar of adjacent electrodes of the surface acoustic wave multimode filter toward both end parts without crossing reflectors and metal strips. CONSTITUTION:A common bus bar 7 of a pair of IDT (interdigital transducer) electrodes 5 and 6, whose number of pairs of electrode fingers is relatively small, formed on a piezoelectric substrate 1 is extended across reflectors 8 and 9 provided on both sides of electrodes 5 and 6 and has the width increased gradually toward outside parts of reflectors 8 and 9. When a bonding wire is stuck to the wider part of the bus bar also, the connection is facilitated, and the ohmic loss is small, and therefore, the loss of the filter is minimized. |
