Electro-mechanical filter including mechanical resonator
AssigneeNippon Bearing Co., Ltd.
InventorKoji Suzuki
Life of this patent
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Abstract
An electromechanical filter having mechanical resonators which is used as a channel filter for a mobile radio communication receiver and a carrier telephone. The electromechanical filter is provided with exciter means, each of which is composed of a transducer and an exciter formed as a unitary structure and has the both functions. Each exciter means is a bar-shaped piezoelectric ceramic having a pair of electrodes deposited on its opposing surfaces and subjected to polarization treatment. The exciter means are mechanically coupled by mechanical coupling means with the mechanical resonators.
Claims4
An electromechanical filter comprising:
- exciter means composed of two or more transducers for exciting a mechanical vibration;
- resonator means composed of one or more mechanical resonators for resonating with the exciter means;
- coupler means composed of one or more mechanical couplers for mechanically coupling the exciter means and the resonator means with each other, the mechanical couplers being disposed to extend across the exciter means and the resonator means almost perpendicularly and secured to the both means;
- in which the transducers are each formed with a thin bar-shaped piezoelectric ceramic having a pair of thin surface layers formed onto its opposing surfaces and being polarized by having a voltage placed across the electrodes,
- and wherein both ends of each of the couplers is extended outwardly, and wherein there is provided support means for fixedly supporting the extended both end portions of the coupler on surfaces of two vertical arms extending almost perpendicularly to the coupler, the support means having at least one horizontal arm for interconnecting the two vertical arms and providing both mechanical support and electrical termination.
Dependencies are inferred from the claim text.