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US3949327A
Expired / Lapsed
US
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Waveguide low pass filter
Assignee: SAGE LABORATORIES Inc
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Filing: 1974-08-01
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Granted: 1976-04-06
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Expires: 1994-08-01
Abstract
Abstract The filter may be designed from a multiple section L-C Chebyshev low pass filter prototype and is of generally ridged filter construction. The distributed shunt capacitors in the ridged section are designed to support only one mode in both the passband and primary stop band. The series inductors are calculated in accordance with evanescent mode (below cut-off) operation.
Inventors
- 👤 Harry F. Chapell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:26
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/207; H01P1/211
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
63 words
A waveguide low pass filter structure comprising sequential ridged waveguide capacitive and inductive sections wherein a shunt capacitance is associated with each ridge and a series inductance exists between ridges, said series inductances being selected for operation in the evanescent mode for the desired passband, and said shunt capacitance selected to support only one mode in both the passband and primary stop band.
Claim 2
Dependent Claim
63 words
A waveguide low pass filter structure comprising sequential ridged waveguide capacitive and inductive sections wherein a shunt capacitance is associated with each ridge and a series inductance exists between ridges, said series inductances being selected for operation in the evanescent mode for the desired passband, and said shunt capacitance selected to support only one mode in both the passband and primary stop band.
Claim 3
Dependent Claim
25 words
The filter structure of claim 1 wherein the maximum inductor length is choosen slightly less than one-half wavelength at the highest frequency to be blocked.
Claim 4
Dependent Claim
19 words
The filter structure of claim 1 wherein the series inductance = j X.sub.o sinh (γl) where ##EQU10## and ##EQU11##
Claim 5
Dependent Claim
17 words
The filter structure of claim 1 wherein the element values are selected from a Chebyshev function prototype.
References Cited (Backward Citations)
US2747184A
Cited
US3597710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |