| 摘要 |
Disclosed is a coplanar waveguide (CPW) which is connected directly into a "balanced SAW transducer" via a tapered coplanar transmission line. Preferably, the CPW transition feeds directly into the "balanced transducer" such that the ground planes of the CPW taper directly into the outer (grounded) bus bars of the SAW transducer and the center conductor of the CPW feeds directly into the "hot" center electrode structure of the SAW transducer. This preferred structure is shown in FIG. 1. This balanced SAW transducer configuration provides better electrical shielding for lower electromagnetic feedthrough suppression and lower spurious signal levels. Moreover, the acoustic wave generated by this "balanced transducer" configuration provides a more uniform acoustic power distribution because the center conductor of the SAW transducer provides a waveguide effect wherein the acoustic energy tends to follow the slow velocity metal structure, thus forming an acoustic waveguide.
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