Surface acoustic wave filter having a continuous electrode for connection of multiple bond wires

Abstract

In A surface acoustic wave filter constituted with a ladder of resonators having a resonance frequency or an anti-resonance frequency, an input current flowing into a resonator in a parallel arm at the first stage from the input is so large as to deteriorate its lifetime caused from a heat generation by the resistance of the thin film wiring. As a measure to this problem, bonding wires (,) connected onto points on connection electrodes (,) for connecting an end of each of plural comb teeth electrodes,forming the resonators R,& R,, or on a lead conductor (,-,) extended longitudinally from the connection electrode, are allotted at both sides of a center line (C,) of the plural comb teeth electrode group. Furthermore, a bonding wire may be connected substantially onto the center line C,as well. It is preferable for the bonding wires to be located substantially symmetric with respect to the center line C,. It is preferable that the width along the longitudinal direction of the comb teeth electrodes is lager than a width of the comb teeth electrode.