Patent JPS5755239A successfully refreshed from Google Patents.
US3605044A
Expired / Lapsed
US
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Filter structures using bimodal, bisymmetric networks
Assignee: AT&T Inc
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Filing: 1968-11-18
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Granted: 1971-09-14
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Expires: 1988-11-18
Abstract
Abstract A variety of filter structures are synthesized by means of a cascade of bimodal networks. By including mode converters between adjacent pairs of networks, successive networks can be made to respond to one or the other of said modes. A transmission line filter and a coupler (channel dropping) filter are described.
Inventors
- 👤 Harold Seidel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:23
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/075; H03H7/0115
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A filter comprising: a cascade of bisymmetrical, bimodal networks all of which are characterized by the same two normal modes; and means, connecting adjacent pairs of said networks, for converting all of the wave energy from one of said normal modes in one network to the other of said normal modes in the next adjacent network.
Claim 2
Dependent Claim
56 words
A filter comprising: a cascade of bisymmetrical, bimodal networks all of which are characterized by the same two normal modes; and means, connecting adjacent pairs of said networks, for converting all of the wave energy from one of said normal modes in one network to the other of said normal modes in the next adjacent network.
Claim 3
Dependent Claim
45 words
The filter according to claim 1 wherein each network comprises a section of cable having two inner conductors surrounded by an outer conductor; and wherein said mode converter comprises means for introducing 180* relative phase shift between signal components propagating along said two inner conductors.
Claim 4
Dependent Claim
20 words
The filter according to claim 1 including means for externally energizing said filter in at least one of said modes.
Claim 5
Dependent Claim
24 words
The filter according to claim 1 including a signal source for simultaneously energizing an external port of said filter in both of said modes.
Claim 6
Dependent Claim
14 words
The filter according to claim 1 wherein each of said networks is a four-port.
Claim 7
Dependent Claim
69 words
The filter according to claim 1 where each of said networks comprises a pair of coupled four-ports, each of which has two axes of symmetry; and wherein two of the ports, symmetrically disposed with respect to one of the axis of one of said four-ports, are connected respectively to two of the ports, symmetrically disposed with respect to the other of said axes, of the other of said four-ports.
Claim 8
Dependent Claim
16 words
The filter according to claim 6 wherein each of said four-ports is a quadrature hybrid coupler.
Claim 9
Dependent Claim
14 words
The filter according to claim 1 wherein each of said bimodal networks is bidual.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |