US5212463A
Expired / Lapsed
US
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Planar ferro-electric phase shifter
Assignee: United States Department of the Army
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Filing: 1992-07-22
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Granted: 1993-05-18
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Expires: 2012-07-22
Abstract
Abstract A planar ferro-electric phase shifter which is compatible with commonly-u microwave transmission media to include microstrip, inverted microstrip, and slot line. The ferro-electric material, Ba x Sr 1-x TiO 3 , which has a high dielectric-constant, is the phase shifting element. In the microstrip embodiment, the microstrip circuit consists of a ferro-electric element interposed between a conductor line and a ground plane. A DC voltage is applied between the conductor line and the ground plane, thereby controlling the dielectric constant of the ferro-electric material. The dielectric constant of the ferro-electric element in turn controls the speed of the microwave signal, which causes a phase shift. Microwave energy is prevented from entering the DC supply by either a high-impedance, low pass filter, or by an inductive coil. DC voltage is blocked from traveling through the microstrip circuit by a capacitive high-voltage DC bias blocking circuit in the ground plane.
Inventors
- 👤 Richard W. Babbitt
- 👤 William C. Drach
- 👤 Thomas E. Koscica
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:49
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/18; H01P1/181
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
178 words
A ferro-electric phase shifter comprising: a conductor line; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, said ferro-electric element being interposed between said conductor line and said ground plane to form a microstrip circuit, and said ferro-electric element having an entry point and exit point; a means integral to said ground plane for blocking DC voltage from traveling through said conductor line, said ferro-electric element, and said ground plane; an impedance matching circuit functionally interposed between said conductor line and said entry point of said ferro-electric element, wherein said impedance matching circuit reduces the signal reflection of a microwave signal traveling through the conductor line and into said ferro-electric element by matching the impedance of said microwave signal to that of said ferro-electric element; and a high-impedance, low pass filter coupled to said ground plane wherein said filter prevents microwave energy from entering the DC voltage applying means.
Claim 2
Dependent Claim
178 words
A ferro-electric phase shifter comprising: a conductor line; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, said ferro-electric element being interposed between said conductor line and said ground plane to form a microstrip circuit, and said ferro-electric element having an entry point and exit point; a means integral to said ground plane for blocking DC voltage from traveling through said conductor line, said ferro-electric element, and said ground plane; an impedance matching circuit functionally interposed between said conductor line and said entry point of said ferro-electric element, wherein said impedance matching circuit reduces the signal reflection of a microwave signal traveling through the conductor line and into said ferro-electric element by matching the impedance of said microwave signal to that of said ferro-electric element; and a high-impedance, low pass filter coupled to said ground plane wherein said filter prevents microwave energy from entering the DC voltage applying means.
Claim 3
Dependent Claim
179 words
A ferro-electric phase shifter comprising: a conductor line; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, said ferro-electric element being interposed between said conductor line and said ground plane to form an inverted microstrip circuit, and said ferro-electric element having an entry point and exit point; a means integral to said ground plane for blocking DC voltage from traveling through said conductor line, said ferro-electric element, and said ground plane; an impedance matching circuit functionally interposed between said conductor line and said entry point of said ferro-electric element, wherein said impedance matching circuit reduces the signal reflection of a microwave signal traveling through the conductor line and into said ferro-electric element by matching the impedance of said microwave signal to that of said ferro-electric element; and a high-impedance, low pass filter coupled to said ground plane wherein said filter prevents microwave energy from entering the DC voltage applying means.
Claim 4
Dependent Claim
179 words
A ferro-electric phase shifter comprising: a conductor line; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, said ferro-electric element being interposed between said conductor line and said ground plane to form an inverted microstrip circuit, and said ferro-electric element having an entry point and exit point; a means integral to said ground plane for blocking DC voltage from traveling through said conductor line, said ferro-electric element, and said ground plane; an impedance matching circuit functionally interposed between said conductor line and said entry point of said ferro-electric element, wherein said impedance matching circuit reduces the signal reflection of a microwave signal traveling through the conductor line and into said ferro-electric element by matching the impedance of said microwave signal to that of said ferro-electric element; and a high-impedance, low pass filter coupled to said ground plane wherein said filter prevents microwave energy from entering the DC voltage applying means.
Claim 5
Dependent Claim
115 words
A ferro-electric phase shifter comprising: a conductor circuit; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, wherein said ferro-electric element, said conductor circuit and said ground plane are arranged to form a slotline circuit, said ferro-electric element being interposed between said conductor circuit and said ground plane; a means integral to said ground plane for blocking DC voltage from traveling through said conductor circuit, said ferro-electric element, and said ground plane; and a means for preventing microwave energy from entering said DC voltage applying means.
Claim 6
Dependent Claim
115 words
A ferro-electric phase shifter comprising: a conductor circuit; a ground plane; a means for applying a DC current between said conductor line and said ground plane; a ferro-electric element of a material possessing a high dielectric constant that can be varied by applying a DC voltage, wherein said ferro-electric element, said conductor circuit and said ground plane are arranged to form a slotline circuit, said ferro-electric element being interposed between said conductor circuit and said ground plane; a means integral to said ground plane for blocking DC voltage from traveling through said conductor circuit, said ferro-electric element, and said ground plane; and a means for preventing microwave energy from entering said DC voltage applying means.
Claim 7
Dependent Claim
28 words
The ferro-electric phase shifter in claim 3 wherein said ferro-electric phase element has a length which is a multiple of one half the wavelength of a microwave signal.
Claim 8
Dependent Claim
23 words
The ferro-electric phase shifter in claim 4 wherein said ferro-electric element is fixed in the slot with a λ/4 fixed-length impedance matching slot.
Claim 9
Dependent Claim
22 words
The ferro-electric phase shifter in claim 5 wherein the slot in said slotline circuit is selected to produce a 50 Ohm circuit.
Claim 10
Dependent Claim
19 words
The ferro-electric phase shifter in claim 6 wherein said DC voltage blockage means is gaps in said ground plane,
Claim 11
Dependent Claim
30 words
The ferro-electric phase shifter in claim 16 wherein said DC voltage blockage means is two gaps in said ground plane, each of said gaps having a thickness of 50-127 microns.
Claim 12
Dependent Claim
22 words
The ferro-electric phase shifter in claim 8 wherein in each of said gaps has a length calculated by the series (λ/4+n λ/2).
Claim 13
Dependent Claim
32 words
The ferro-electric phase shifter in claim 9 wherein said DC applying means is a coil which allows the DC signal to pass while acting as an open circuit for the microwave signal.
References Cited (Backward Citations)
US4105959A
Cited
US5032805A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |