Patent US3723920A successfully refreshed from Google Patents.
US3723920A
Expired / Lapsed
US
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Crystal filter assembly
Assignee: AG Communication Systems Corp
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Filing: 1971-06-24
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Granted: 1973-03-27
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Expires: 1991-06-24
Abstract
Abstract In this filter, each one of two coupled resonators is formed on a different crystal wafer. Each wafer is accurately positioned with respect to one longitudinal groove in the periphery of a ceramic ring. The wafer is supported in the central opening in the ring with wires which are soldered to metalized areas of the ring and to resonator lead patterns on the wafer to form a resonator assembly. Each resonator is tuned to operate at a predetermined frequency by locating the associated resonator assembly in a masking jig with respect to the one groove on the ring to accurately align the resonator electrode patterns with holes in the jig. A metal film is evaporated onto a resonator electrode to adjust the resonant frequency of the associated resonator to be equal to the predetermined frequency. In a packaged filter the resonator assemblies and electrically conductive spacers are alternately stacked on a header having a pair of posts protruding therefrom that are located in longitudinal grooves in the ceramic rings and openings in the spacers for supporting the stacked elements. Extensions and tabs on the spacers are soldered to the alignment posts and metalized areas on the rings, respectively, to ground the resonators and spacers to the header. The spacer sandwiched between the rings provides isolation between the resonators on adjacent wafers. A discrete chip capacitor is connected to a resonator electrode and a metalized area on a ring which is grounded to the header. The resonator electrodes are also selectively interconnected and connected to insulated lead pins in the header to produce a filter structure. The packaged filter is hermetically sealed by cold welding a cover to the header.
Inventors
- 👤 D Sheahan
- 👤 G Callander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:17
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/02; H03H9/05; H03H9/0504; H03H9/0528; H03H9/10; H03H9/1007; H03H9/1014; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
206 words
A filter assembly comprising, in combination, a header having a base with a pair of posts rigidly secured therein and a pair of electrical lead pins dielectrically supported therein and extending therethrough; a plurality of resonator assemblies, each resonator assembly comprising a dielectric frame having an opening therethrough, having a pair of grooves in the periphery thereof with the same relative spacing as said posts, and having a plurality of metallic electrodes spaced apart on the surface thereof adjacent the opening therein, a piezoelectric crystal body having a pair of opposing major faces, said crystal body being smaller than the opening in said frame, a conductive electrode pattern formed on each of said major faces of said crystal body, said patterns comprising overlapping body patterns and lead patterns connected to the body patterns, said body patterns and crystal body together forming an acoustic resonator, and first means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the opening in said frame; said resonator assemblies being stacked on said header with said posts in said grooves; and second means selectively electrically connecting said resonators together and to said header lead pins to form a network having a prescribed frequency response characteristic.
Claim 2
Dependent Claim
206 words
A filter assembly comprising, in combination, a header having a base with a pair of posts rigidly secured therein and a pair of electrical lead pins dielectrically supported therein and extending therethrough; a plurality of resonator assemblies, each resonator assembly comprising a dielectric frame having an opening therethrough, having a pair of grooves in the periphery thereof with the same relative spacing as said posts, and having a plurality of metallic electrodes spaced apart on the surface thereof adjacent the opening therein, a piezoelectric crystal body having a pair of opposing major faces, said crystal body being smaller than the opening in said frame, a conductive electrode pattern formed on each of said major faces of said crystal body, said patterns comprising overlapping body patterns and lead patterns connected to the body patterns, said body patterns and crystal body together forming an acoustic resonator, and first means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the opening in said frame; said resonator assemblies being stacked on said header with said posts in said grooves; and second means selectively electrically connecting said resonators together and to said header lead pins to form a network having a prescribed frequency response characteristic.
Claim 3
Dependent Claim
62 words
The filter assembly according to claim 1 including an electrically conductive spacer sandwiched between adjacent resonator assemblies, said spacer having a body section between electrode body patterns on adjacent crystal bodies for providing isolation therebetween, having a pair of openings therein with the same relative spacing as said posts, and being stacked on said header with said posts in said spacer openings.
Claim 4
Dependent Claim
36 words
The filter assembly according to claim 2 including means for dielectrically spacing said spacer from said crystal bodies, said second connecting means including third means electrically connecting at least one spacer to one of said posts.
Claim 5
Dependent Claim
28 words
The filter assembly according to claim 3 wherein said dielectric spacing means comprises at least one raised section on the surface of said frame supporting said metallic electrodes.
Claim 6
Dependent Claim
100 words
The filter assembly according to claim 4 wherein said frames are dielectric rings each having a central opening therein, having a pair of longitudinal grooves in the circumference thereof, and having a raised position in the one end thereof that supports said metallic electrodes, said metallic electrodes being continuously formed on the one end and circumference of said ring; wherein said crystal bodies are wafers; and wherein said first connecting means comprises wires selectively electrically connected between metallic electrodes on said ring and lead patterns on said wafer when said wafer is located in the central opening in said ring.
Claim 7
Dependent Claim
67 words
The filter assembly according to claim 5 wherein each spacer comprises a plurality of tabs extending from said spacer body and having the same relative spacing as metallic electrodes on said rings, some of said tabs being electrically connected to metallic electrodes on the circumference of one adjacent ring, other of said tabs being electrically connected to metallic electrodes on the circumference of the other adjacent ring.
Claim 8
Dependent Claim
31 words
The filter assembly according to claim 6 including a cover over said stacked resonator assemblies and spacers, said cover being secured to said header base for hermetically sealing said filter assembly.
Claim 9
Dependent Claim
16 words
The filter assembly according to claim 7 wherein said second connecting means comprises a chip capacitor.
Claim 10
Dependent Claim
34 words
The filter assembly according to claim 8 wherein one of said spaCer tabs is connected to one of said metallic electrodes that is connected to a lead pattern for grounding one of said resonators.
Claim 11
Dependent Claim
48 words
The filter assembly according to claim 9 for mounting on a circuit board, said filter assembly including a plurality of protrusions in the header base extending away from said stacked resonator assemblies and spacers for spacing said header base from the circuit board adjacent the header lead pins.
Claim 12
Dependent Claim
209 words
A filter assembly comprising, in combination, a header having a base with a pair of posts rigidly secured therein and a pair of electrical lead pins dielectrically supported therein; a plurality of stackable resonator assemblies, each resonator assembly comprising a dielectric frame having a first opening therein, having second and third openings therethrough with the same relative spacing as said posts, and having a plurality of metallic electrodes spaced apart on the surface thereof adjacent the first opening therein, a piezoelectric crystal body having a pair of opposing major faces, said crystal body being smaller than the first opening in said frame, a conductive electrode pattern formed on each of said major faces of said crystal body, said electrode patterns comprising overlapping body patterns and lead patterns connected to the body patterns, said body patterns and crystal body together forming an acoustic resonator, and first means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the first opening in said frame; said resonator assemblies being stacked on said header with said posts in associated second and third openings; and second means selectively electrically connecting said resonators together and to said header lead pins to form a network having a prescribed frequency response characteristic.
Claim 13
Dependent Claim
209 words
A filter assembly comprising, in combination, a header having a base with a pair of posts rigidly secured therein and a pair of electrical lead pins dielectrically supported therein; a plurality of stackable resonator assemblies, each resonator assembly comprising a dielectric frame having a first opening therein, having second and third openings therethrough with the same relative spacing as said posts, and having a plurality of metallic electrodes spaced apart on the surface thereof adjacent the first opening therein, a piezoelectric crystal body having a pair of opposing major faces, said crystal body being smaller than the first opening in said frame, a conductive electrode pattern formed on each of said major faces of said crystal body, said electrode patterns comprising overlapping body patterns and lead patterns connected to the body patterns, said body patterns and crystal body together forming an acoustic resonator, and first means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the first opening in said frame; said resonator assemblies being stacked on said header with said posts in associated second and third openings; and second means selectively electrically connecting said resonators together and to said header lead pins to form a network having a prescribed frequency response characteristic.
Claim 14
Dependent Claim
23 words
The filter assembly according to claim 11 wherein the body patterns are aligned in the first opening with respect to the second opening.
Claim 15
Dependent Claim
148 words
A stackable resonator assembly for use in a stacked crystal filter assembly comprising a dielectric frame having a pair of essentially parallel faces, having first and second openings in said frame faces, and having a plurality of metallic electrodes spaced apart on the frame face adjacent the first opening therein, a piezoelectric crystal body having a pair of opposing major faces, being smaller than the first opening, and being aligned in the first opening with respect to the second opening, a conductive electrode pattern formed on each of said major faces of said crystal body, said electrode patterns comprising overlapping body patterns with lead patterns connected to the body patterns, said electrode body patterns and crystal body together forming an acoustic resonator, and means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the first opening with respect to the second opening.
Claim 16
Dependent Claim
148 words
A stackable resonator assembly for use in a stacked crystal filter assembly comprising a dielectric frame having a pair of essentially parallel faces, having first and second openings in said frame faces, and having a plurality of metallic electrodes spaced apart on the frame face adjacent the first opening therein, a piezoelectric crystal body having a pair of opposing major faces, being smaller than the first opening, and being aligned in the first opening with respect to the second opening, a conductive electrode pattern formed on each of said major faces of said crystal body, said electrode patterns comprising overlapping body patterns with lead patterns connected to the body patterns, said electrode body patterns and crystal body together forming an acoustic resonator, and means electrically connecting said lead patterns to associated metallic electrodes for supporting said crystal body in the first opening with respect to the second opening.
Claim 17
Dependent Claim
24 words
The resonator assembly according to claim 13 including a third opening in said frame, said second and third openings extending through the frame faces.
Claim 18
Dependent Claim
23 words
The resonator assembly according to claim 14 wherein the body patterns are aligned in the first opening with respect to the second opening.
Claim 19
Dependent Claim
21 words
The resonator assembly according to claim 15 wherein said second and third openings are grooves in the periphery of said frame.
Claim 20
Dependent Claim
56 words
The resonator assembly according to claim 16 wherein said frame is a dielectric ring having a central opening therethrough and a pair of longitudinal grooves that are diagonally spaced apart in the periphery thereof; and wherein said crystal body is a wafer that is aligned in the central opening with respect to one of said grooves.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |