US4291287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Evanescent mode filter
Assignee: The AT&T MVPD Group LLC
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Filing: 1979-12-10
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Granted: 1981-09-22
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Expires: 1999-12-10
Abstract
Abstract There are herein described evanescent mode filters each of which include a hollow waveguide, wherein a plurality of resonators are disposed, the resonators including loading structures such as tuning screws, for example, wherein at least one of the loading structures is angularly disposed, relative to the axis of the waveguide, with respect to others of the loading structures to reduce the length of the filter and/or to provide internal bridge couplings.
Inventors
- 👤 Frederick A. Young
- 👤 Edward L. Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:28
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/219
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member, alternate ones of said resonators forming internal bridge couplings; and an evanescent resonator loading structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures.
Claim 2
Dependent Claim
130 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member, alternate ones of said resonators forming internal bridge couplings; and an evanescent resonator loading structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures.
Claim 3
Dependent Claim
136 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member; and an evanescent resonator including structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures and generally lying on a helical path about said side wall of said waveguide member.
Claim 4
Dependent Claim
136 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member; and an evanescent resonator including structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures and generally lying on a helical path about said side wall of said waveguide member.
Claim 5
Dependent Claim
131 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow cylindrical waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member, alternate ones of said resonators forming internal bridge couplings; and an evanescent resonator loading structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures.
Claim 6
Dependent Claim
131 words
An evanescent mode filter for ultra-high and microwave frequency bandpass filter applications, comprising: a hollow cylindrical waveguide member dimensioned below cutoff at an operating frequency, said waveguide member including a side wall and an input end and an opposite output end; input/output coupling means associated with said input and output ends of said cylindrical waveguide member for respectively coupling RF energy into and out of said evanescent mode filter; a plurality of evanescent resonators disposed in said waveguide member, alternate ones of said resonators forming internal bridge couplings; and an evanescent resonator loading structure disposed in each of said evanescent resonators, at least one of said loading structures being oriented about the axis of said waveguide member at an angle with respect to at least one other of said loading structures.
References Cited (Backward Citations)
GB2006539A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |