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Patent US4814780A successfully refreshed from Google Patents.
US4814780A
Expired / Lapsed
US
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Variable directional coupler
Assignee: ITT Gilfillan Inc
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Filing: 1988-03-11
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Granted: 1989-03-21
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Expires: 2008-03-11
Abstract
Abstract The variable directional coupler of the subject invention employs 3, 4 or n branches in TEM transmission media, such as coax, stripline and microstrip. Precise control of the coupling is acheived by a variable susceptance connected near the mid-point of the crossover.
Inventors
- 👤 William G. Sterns
- 👤 Ching-Fai Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:19
CPC Classifications
H; H01; H01P; H01P5/00; H01P5/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
63 words
A variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling.
Claim 2
Dependent Claim
63 words
A variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling.
Claim 3
Dependent Claim
12 words
The coupler of claim 1 in which said adjustable susceptances are capacitors.
Claim 4
Dependent Claim
22 words
The coupler of claim 1 in which said adjustable susceptances are varactor diodes in order to provide electronic control of the coupling.
Claim 5
Dependent Claim
33 words
The coupler of claim 1 in which said adjustable susceptances are reactively terminated transmission-line sections for producing a frequency-sensitive coupler having exact control of either a positive or negative amplitude slope with frequency.
Claim 6
Dependent Claim
98 words
In combination: a variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling and a dual polarized array antenna having dual inputs connected to said output and coupled ports in order to correct for polarization impurities caused by the different mutual couplings of the two polarizations.
Claim 7
Dependent Claim
98 words
In combination: a variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling and a dual polarized array antenna having dual inputs connected to said output and coupled ports in order to correct for polarization impurities caused by the different mutual couplings of the two polarizations.
Claim 8
Dependent Claim
34 words
The coupler of claim 5 in which said adjustable susceptances are reactively terminated transmission line sections for producing a frequency-sensitive coupler having exact control of either a positive or negative amplitude slope with frequency.
Claim 9
Dependent Claim
88 words
In combination: a variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween, including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling and a dual polarized antenna having dual inputs connected to said output and coupled ports wherein polarization impurities result from nonperfect feed systems.
Claim 10
Dependent Claim
88 words
In combination: a variable directional coupler in TEM transmission media such as coax, stripline or microstrip having two parallel transmission lines containing input, output, coupled and isolated ports and having at least three branches connected therebetween, including first and last branches wherein continuously adjustable susceptances are connected from near the midpoints of said first and last branches to ground in order to precisely control coupling and a dual polarized antenna having dual inputs connected to said output and coupled ports wherein polarization impurities result from nonperfect feed systems.
Claim 11
Dependent Claim
34 words
The coupler of claim 7 in which said adjustable susceptances are reactively terminated transmission-line sections for producing a frequency sensitive coupler having exact control of either a positive or negative amplitude slope with frequency.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |