Three-transducer saw device including one or two apodized transducers having minimum-phase and maximum-phase impulse responses
First Claim
1. A surface acoustic wave device including an interdigital electrode member having first and second ends and a predetermined width of interlock and a first apodized electrode member having a substantially minimum-phase impulse response for a first surface acoustic wave propagated between said interdigital and said first apodized electrode member through said first end, wherein the improvement comprises a second apodized electrode member and connecting means for electrically connecting said first and said second apodized electrode members together, said second apodized electrode member having a substantially maximum-phase impulse response to a second surface acoustic wave propagated between said interdigital and said second apodized electrode members through said second end.
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Accused Products
Abstract
In a three-transducer surface acoustic wave device, an apodized electrode member is interposed between two interdigital electrode members, each having first and second ends and comprising interdigital electrodes between the first and the second ends either with a uniform density distribution or with a density distribution varied according to a prescribed rule of selective withdrawal of the interdigital electrodes. The apodized electrode member has first and second extremities and is given substantially minimum-phase and maximum-phase impulse responses for surface acoustic waves which are propagated either into or out of the apodized electrode member through one and the other of the extremities. Alternatively, an interdigital electrode member is interposed between two apodized electrode members. Each of the interdigital and the apodized electrode members is of the type described above. One of the apodized electrode member should have a substantially minimum-phase impulse response. The other should have a substantially maximum-phase impulse response.
12 Citations
7 Claims
- 1. A surface acoustic wave device including an interdigital electrode member having first and second ends and a predetermined width of interlock and a first apodized electrode member having a substantially minimum-phase impulse response for a first surface acoustic wave propagated between said interdigital and said first apodized electrode member through said first end, wherein the improvement comprises a second apodized electrode member and connecting means for electrically connecting said first and said second apodized electrode members together, said second apodized electrode member having a substantially maximum-phase impulse response to a second surface acoustic wave propagated between said interdigital and said second apodized electrode members through said second end.
Specification