Focusing transformers/filters in isotropic/anisotropic piezoelectrics
| DWPI Title: Focusing interdigital transducer for use in dual-port transformer and single-port filter, has first set of transducers fingers formed on top surface of piezoelectric layer, and first bus formed on top surface of piezoelectric layer |
| Abstract: A focusing interdigital transducer (IDT) and corresponding single- and dual-port piezoelectric devices are disclosed. The focusing interdigital transducer, which generates Lamé acoustic waves, permits operation at significantly higher frequencies than those possible with traditional IDTs. The focusing IDT employs multiple arced fingers formed both above and below the piezoelectric layer to improve coupling efficiency by coupling through both the e31 and e33 piezoelectric coefficients to the piezoelectric layer. By optimizing both anchor design and location, acoustic wave losses are minimized, thereby improving the device's quality factor Q. Through proper bus design and selection of the number of IDT fingers, a device's impedance can be tuned for a given application. The focusing IDTs may be used in single-port filter devices and dual-port transformer devices. The single- and dual-port devices may operate at a single frequency, at two frequencies, or over a band of frequencies. |
| Use: Focusing interdigital transducer for use in a dual-port transformer and a single-port filter (all claimed). |
| Advantage: The transducer connects positive voltage output fingers to secondary positive voltage output bus so as to improve coupling efficiency between the piezoelectric layer and the positive voltage output fingers in an effective manner. |
| Novelty: The transducer (400) i.e. surface acoustic wave resontor for obtaining specific frequency has a first set of interdigital transducers (IDT) fingers (420) formed on a top surface of a piezoelectr Text Colouric layer (410). A first bus (430) is formed on a top surface of the piezoelectric layer, and electrically connected to the first set of IDT fingers. A second set of IDT fingers (422) is formed on the top surface of the piezoelectric layer. A second bus is formed on the top surface of the piezoelectric layer and electrically connected to the second set of IDT fingers. Third and fourth set of IDT fingers (424,450) for obtaining specific frequency are formed on a bottom surface of the piezoelectric layer. Third and fourth buses are formed on the bottom surface of the piezoelectric layer and electrically connected to the third and fourth set of IDT fingers. The first, second, third, and fourth set of IDT fingers are adapted to create Lame waves in the piezoelectric layer. |
| Filed: 9/3/2019 |
| Application Number: US16558453A |
| Tech ID: SD 14716.0 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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