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US 4,047,129 AGranted
Elastic surface wave filter
AssigneeMurata Manufacturing Co., Ltd.
InventorHideki Ishiyama
Life of this patent
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Abstract
An elastic surface wave filter having a substrate of ceramic material and input and output transducer electrodes of interleaved-comb-type rigidly mounted on one surface of the substrate. A top covering is mounted on the electrode-mounted surface of the substrate. This substrate concurrently serves as a medium through which, when the filter is energized, an elastic surface wave is propagated from the input transducer electrode towards the output transducer electrode and also as a closure for closing the opening of the top covering.
Claims11
An elastic surface wave filter which comprises:
- a substrate of peizoelectric property having opposed surfaces and interleaved-comb-type transducer electrodes formed on one of said opposed surfaces, one of said transducer electrodes being adapted to be coupled to a source of electric input signal and the other said transducer electrodes being adapted to be coupled to an external load circuitry, said transducer electrodes being formed on said one of said opposed surfaces of said piezoelectric substrate in spaced, but piezoelectrically coupled, relation to each other;
- a top covering rigidly mounted on said one of said opposed surfaces of said piezoelectric substrate and defining an interior chamber between said top covering and said substrate;
- each of said transducer electrodes including a pair of comb-type electrode arrays interleaved with each other;
- and
- elongated terminal members one for each comb-type electrode array, each of said elongated terminal members having one end coupled to the associated comb-type electrode array and the other end extending outwardly from said substrate for external electrical connection.
2 more elements
Dependencies are inferred from the claim text.