Thin-film integrated circuit with tank circuit characteristics and applications to thin-film filters and oscillators

摘要

A thin-film integrated circuit with tank circuit characteristics may comprise a surface acoustic wave transducer with appropriate geometry. A preferred embodiment of such integrated circuit includes, in addition to the surface acoustic wave transducer, surface acoustic wave reflecting means located adjacent the transducer, and preferably on opposite sides thereof. The reflecting means may include a pair of reflectors and be proportioned so that the device exhibits a single resonant-anti-resonant frequency pair, such as a single tank circuit. Alternatively, the reflectors may be proportioned such that the device exhibits multiple resonant-anti-resonant frequency pairs. The operating frequency may be as high as hundreds of megahertz to one gigahertz.PP Applications of the thin-film integrated circuit to thin-film filters and oscillators are also disclosed.P PIn addition a novel form of surface acoustic wave transducer is disclosed which exhibits lower equivalent capacitance than do prior art surface acoustic wave transducers.