Filter device

Claim 2

A piezoelectric ceramic resonator of the slotted-plate type for use in a filter assembly comprising, a unitary, generally flat, symmetrically-shaped body made of piezoelectric ceramic material and defined by an outer peripheral edge, said body includes an opening having one portion disposed inwardly of said peripheral edge and a slot portion which extends to said peripheral edge defining a pair of laterally extending arms, said arms are integrally connected to one another at one of their ends by a connecting portion of said body and are spaced apart from one another at their opposite ends to enable vibration thereof, said body includes spaced mounting regions disposed adjacent said connected ends of said arms and being separated by said connecting portion for mounting said resonator in a filter assembly, electrode means on said body adjacent said mounting regions for electrical contact of said resonator in a filter assembly, and said body is of one transverse width dimension across said mounting regions and of a reduced transverse width across said connecting portion as measured in a transverse direction between said one portion of said opening and said outer peripheral edge of said body whereby the compliance of said resonator is confined by limiting the shift of its nodal points as the resonator frequency is tuned to different frequencies.

Claim 3

A resonator in accordance with claim 1, wherein each of said mounting regions is located in a respective one of said arms.

Claim 4

A resonator in accordance with claim 1, wherein said body includes a nodal point located in each of said arms, and each of said mounting regions has a maximum width in a direction extending generally along an imaginary line which extends through a respective one of said nodal points and the center of symmetry of said one portion of said opening.

Claim 5

A resonator in accordance with claim 2, wherein said connecting portion of said body is defined in part by at least one linear peripheral edge portion which extends generally symmetrically with respect to the center of symmetry of said one portion of said opening.

Claim 6

A resonator in accordance with claim 4, wherein said body is generally polygonal in configuration with said connecting portion being further defined by a pair of corner edge portions which extend angularly outwardly from the opposite ends of said one linear peripheral edge portion defining a pair of junctures, and said corner edge portions extend angularly outwardly away from one another in a direction toward said opposite end of said arms being disposed generally symmetrically with respect to the center of symmetry of said one portion of said opening.

Claim 7

A resonator in accordance with claim 1, wherein said connecting portion has a minimum width along an imaginary line which extends between said mounting regions and bisects said body.

Claim 8

A resonator in accordance with claim 5, wherein said slot extends to one corner of said body, said one linear peripheral edge extends generally symmetrically with respect to the center of symmetry of said one portion of said opening and said one corner.

Claim 9

A resonator in accordance with claim 7, wherein said one portion of said opening is generally circular in configuration having a diameter greater than the maximum transverse width of said slot as measured in the transverse direction between said arms. said slot exteNds radially outwardly from said one portion, and each of said mounting regions has a maximum width in a direction extending generally along an imaginary line which extends through a respective one of said nodal points and the geometrical center of said one portion.

Claim 10

A resonator in accordance with claim 7, wherein said body is generally square in configuration.

Claim 11

A resonator in accordance with claim 1, wherein said electroded means comprises an electrically conductive material on said body, said opening is defined by an interior marginal edge, and said conductive material is disposed over spaced areas on at least one side of said body having one area extending laterally along a segmental portion of said interior marginal edge adjacent said one portion of said opening, and another area extending laterally along an adjacent segmental portion of said outer peripheral edge of said body.

Claim 12

A resonator in accordance with claim 10, wherein said conductive material is disposed on the opposite side of said body over an area extending between said segmental portion of said interior marginal edge adjacent said one portion of said opening and said segmental portion of said outer peripheral edge of said body.

Claim 13

A filter assembly comprising, in combination a resonator, said resonator comprising a unitary, generally flat, symmetrically-shaped body defined by an outer peripheral edge, said body includes an opening having one portion disposed inwardly of said peripheral edge and a slot portion which extends to said peripheral edge defining a pair of laterally-extending arms, said arms are integrally connected to one another at one of their ends by a connecting portion of said body and are spaced apart from one another at their opposite ends to enable vibration thereof, said body includes spaced mounting regions disposed adjacent said connected ends of said arms and being separated by said connecting portion for mounting said resonator in a filter assembly, electrode means on said body adjacent said mounting regions for electrical contact of said resonator in a filter assembly, a mounting assembly for supportingly engaging said body adjacent said mounting regions in contact with said electrode means, said mounting assembly including a base having a set of terminal leads mounted thereon, an electrically conductive support means supported by said base and engaging said body adjacent said mounting regions and in contact with said electrode means for electrically connecting said body to said terminal leads, and said body being of one transverse width adjacent said mounting regions and a reduced width adjacent said connecting portion as measured in a transverse direction between said opening and said outer peripheral edge of said body whereby the compliance of said resonator is confined by limiting the shift of its nodal points as the resonator frequency is tuned to different frequencies.

Claim 14

A filter assembly comprising, in combination a resonator, said resonator comprising a unitary, generally flat, symmetrically-shaped body defined by an outer peripheral edge, said body includes an opening having one portion disposed inwardly of said peripheral edge and a slot portion which extends to said peripheral edge defining a pair of laterally-extending arms, said arms are integrally connected to one another at one of their ends by a connecting portion of said body and are spaced apart from one another at their opposite ends to enable vibration thereof, said body includes spaced mounting regions disposed adjacent said connected ends of said arms and being separated by said connecting portion for mounting said resonator in a filter assembly, electrode means on said body adjacent said mounting regions for electrical contact of said resonator in a filter assembly, a mounting assembly for supportingly engaging said body adjacent said mounting regions in contact with said electrode means, said mounting assembly including a base having a set of terminal leads mounted thereon, an electrically conductive support means supported by said base and engaging said body adjacent said mounting regions and in contact with said electrode means for electrically connecting said body to said terminal leads, and said body being of one transverse width adjacent said mounting regions and a reduced width adjacent said connecting portion as measured in a transverse direction between said opening and said outer peripheral edge of said body whereby the compliance of said resonator is confined by limiting the shift of its nodal points as the resonator frequency is tuned to different frequencies.

Claim 15

An assembly in accordance with claim 12, wherein said support means engages said body in said mounting region over an area which extends beyond the location of its nodal points whereby the support of said body is maximized.

Claim 16

An assembly in accordance with claim 12, wherein said body includes a nodal point located in each of said arms, each of said mounting regions has a maximum width in a direction extending generally along an imaginary line which extends through a respective one of said nodal points and the center of symmetry of said one portion of said opening.

Claim 17

An assembly in accordance with claim 12, wherein said support means comprises a pair of circuit boards disposed on opposite sides of said body, and a pair of generally flat elastomeric mounting members mounted on each of said circuit boards for engagement with the opposite sides of said body.

Claim 18

An assembly in accordance with claim 15, wherein each of said mounting members includes a generally flat base portIon having one side adhesively secured to an associated circuit board, and a pair of raised laterally-spaced pads disposed on the opposite side of said base portion for engaging said body.

Claim 19

An assembly in accordance with claim 16, wherein each of said pads is of an elongated, prismatic configuration having a lengthwise extending apex edge, and said apex edges of said pads extend in angular relation with one another being disposed in engagement with said body along said mounting lines.

Claim 20

An assembly in accordance with claim 15, wherein each of said mounting members includes a set of apertures therethrough, and resilient conductor means disposed in said apertures for electrically connecting said body to said terminal leads.

Claim 21

An assembly in accordance with claim 18, wherein said resilient conductor means comprise helical springs having highly compliant characteristics, and said springs are secured to said body, the circuit board and the interior walls of said apertures by an elastomeric adhesive having low viscosity characteristics to provide a high degree of decoupling to the resonator 4 with a minimum of damping and mechanical support.

Claim 22

An assembly in accordance with claim 15, wherein said mounting members are made of a molded elastomeric construction to provide stable elastic properties as a function of temperature.

Claim 23

An assembly in accordance with claim 16, wherein said electroded means comprises electrically conductive strips on the sides of said body, said mounting members include a pair of apertures therein, one of said apertures is disposed adjacent one end of one of said pads and the other of said apertures pads, and helical springs are disposed in said apertures being biased between said body and said circuit board for electrically connecting said body with said terminal leads.

Claim 24

An assembly in accordance with claim 15, including a connector element extends between and interconnects said circuit boards with one another to add rigidity to said mounting assembly.

Claim 25

An assembly in accordance with claim 22, wherein said connector element comprises a clip which extends through said opening being bent adjacent its opposite ends for engaging the sides of said circuit boards opposite from said support members.

Claim 26

A filter assembly comprising, in combination a resonator having a unitary, generally flat, symmetrically-shaped body, said body includes spaced mounting regions disposed adjacent generally symmetrically located nodal points, electrode means on said body adjacent said mounting regions to provide an electrical contact for said resonator when in the mounted position in the filter assembly, a mounting assembly for supportingly engaging said body adjacent said mounting regions, said mounting assembly includes a base having a set of terminal leads mounted thereon, an electrically conductive support means supported by said base and engaging said body adjacent said mounting regions for electrically connecting said body to said terminal leads, said support means includes elastomeric mounting means engaging said body adjacent said mounting regions over an area which extends beyond the location of said nodal points of said body, a resilient conductor means supported by said mounting means for compressive contact with said electrode means by said mounting means, and said resilient conductor means being less subject to compressive set than said mounting means whereby said conductor means will have more uniform compressive force characteristics when subjected to compressive force over a period of time when in said filter assembly than said mounting means to assure electrical contact with said resonator.

Claim 27

A filter assembly comprising, in combination a resonator having a unitary, generally flat, symmetrically-shaped body, said body includes spaced mounting regions disposed adjacent generally symmetrically located nodal points, electrode means on said body adjacent said mounting regions to provide an electrical contact for said resonator when in the mounted position in the filter assembly, a mounting assembly for supportingly engaging said body adjacent said mounting regions, said mounting assembly includes a base having a set of terminal leads mounted thereon, an electrically conductive support means supported by said base and engaging said body adjacent said mounting regions for electrically connecting said body to said terminal leads, said support means includes elastomeric mounting means engaging said body adjacent said mounting regions over an area which extends beyond the location of said nodal points of said body, a resilient conductor means supported by said mounting means for compressive contact with said electrode means by said mounting means, and said resilient conductor means being less subject to compressive set than said mounting means whereby said conductor means will have more uniform compressive force characteristics when subjected to compressive force over a period of time when in said filter assembly than said mounting means to assure electrical contact with said resonator.

Claim 28

An assembly in accordance with claim 24, wherein said electrically conductive support means includes a pair of circuit boards disposed on opposite sides of said body, and said resilient conductor means bEing supported in compression between said circuit boards and said resonator.

Claim 29

An assembly in accordance with claim 24, wherein said mounting members are made of a moulded elastomeric construction providing stable elastic properties as a function of temperature.

Claim 30

An assembly in accordance with claim 24, wherein said resilient conductor means comprises helical springs having highly compliant characteristics providing a high degree of decoupling to said resonator with a minimum of damping and mechanical support.