Patent US4554549A successfully refreshed from Google Patents.
US4554549A
Expired / Lapsed
US
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Microstrip antenna with circular ring
Assignee: Raytheon Co
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Filing: 1983-09-19
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Granted: 1985-11-19
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Expires: 2003-09-19
Abstract
Abstract A radar antenna is shown in a first embodiment to have a ground plane and a feed line on opposite sides of a dielectric sheet and a ring-shaped antenna element on another dielectric sheet to form a microstrip assembly wherein such antenna element is capacitively coupled to the feed line. In a second embodiment the radar antenna has a parasitic antenna element on still another dielectric sheet, such parasitic antenna element being in register with the ring-shaped antenna element.
Inventors
- 👤 Matthew Fassett
- 👤 John F. Toth
- 👤 Michael L. Lewis
- 👤 William F. Miccioli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:12
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/0407; H01Q9/045; H01Q9/0457; H01Q19/00; H01Q19/005; H01Q9/0464
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
A radar antenna comprising: (a) a first and a second dielectric sheet in abutting relationship one to the other; (b) a ground plane printed on, and covering, the free surface of the first dielectric sheet; (c) at least one antenna element printed on the free surface of the second dielectric sheet, such antenna element having the shape of a ring, the mean circumference of such ring being equal to one wavelength of radio frequency energy at a desired frequency and in the effective air/dielectric medium; (d) a feed line printed on an abutting surface of one of the dielectric sheets, such feed line being tangential to the antenna element and being terminated in an open circuit; and (e) means for applying radio frequency energy to the feed line to couple such energy capacitively to the at least one antenna element.
Claim 2
Dependent Claim
140 words
A radar antenna comprising: (a) a first and a second dielectric sheet in abutting relationship one to the other; (b) a ground plane printed on, and covering, the free surface of the first dielectric sheet; (c) at least one antenna element printed on the free surface of the second dielectric sheet, such antenna element having the shape of a ring, the mean circumference of such ring being equal to one wavelength of radio frequency energy at a desired frequency and in the effective air/dielectric medium; (d) a feed line printed on an abutting surface of one of the dielectric sheets, such feed line being tangential to the antenna element and being terminated in an open circuit; and (e) means for applying radio frequency energy to the feed line to couple such energy capacitively to the at least one antenna element.
References Cited (Backward Citations)
US3665480A
Cited
US4054874A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |