US3932876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Short end-fire circularly polarized antenna
Assignee: SPX Technologies Inc
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Filing: 1974-08-09
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Granted: 1976-01-13
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Expires: 1994-08-09
Abstract
Abstract A circularly polarized antenna having an end fed short length helical conductor within a conductive funnel-shaped reflector is described. A broad beam width and a relatively low axial ratio is achieved by the termination of the short length helical conductor about a conductive disk and by providing a reflector of shallow depth.
Inventors
- 👤 Oded Ben-Dov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:22
CPC Classifications
H; H01; H01Q; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/185; H01Q11/00; H01Q11/02; H01Q11/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
100 words
An end-fire helical antenna comprising: a funnel-shaped, electrically conductive reflector having a base at one end and tapering sides to a larger aperture at the opposite end, a helical coil extending in an axial direction from a fixed point near the base of the reflector to the plane of the aperture, said helical coil having a given diameter and pitch such that one turn equals approximately one wavelength at an operating frequency of said antenna, a flat conductive plate connected to the aperture end of said helical coil, and means for conductively mounting said flat plate to said funnel-shaped reflector.
Claim 2
Dependent Claim
100 words
An end-fire helical antenna comprising: a funnel-shaped, electrically conductive reflector having a base at one end and tapering sides to a larger aperture at the opposite end, a helical coil extending in an axial direction from a fixed point near the base of the reflector to the plane of the aperture, said helical coil having a given diameter and pitch such that one turn equals approximately one wavelength at an operating frequency of said antenna, a flat conductive plate connected to the aperture end of said helical coil, and means for conductively mounting said flat plate to said funnel-shaped reflector.
Claim 3
Dependent Claim
53 words
The combination claimed in claim 1 wherein said flat plate is electrically connected to said helical coil at the extreme aperture end of the helical coil and at points along the coil approximately a quarter wavelength, a half wavelength and three quarters of a wavelength from said extreme end of said helical coil.
Claim 4
Dependent Claim
38 words
The combination claimed in claim 2 wherein each of said points along said coil are connected to different points on said flat plate that are substantially equally spaced from each other near the periphery of said flat plate.
Claim 5
Dependent Claim
34 words
The combination claimed in claim 1 wherein said means for conductively mounting includes a post of conductive material that is connected between the center of said base and the center of said flat plate.
Claim 6
Dependent Claim
21 words
The combination claimed in claim 1 wherein said coil is two wavelengths long with an axial length of about 0.22 wavelengths.
Claim 7
Dependent Claim
36 words
The combination claimed in claim 5 wherein said base is flat and the diameter of said flat base of said reflector is 0.4 wavelengths and the diameter of said aperture of said reflector is 0.58 wavelengths.
Claim 8
Dependent Claim
14 words
The combination claimed in claim 6 wherein said flat plate is a circular disk.
Claim 9
Dependent Claim
15 words
The combination claimed in claim 7 wherein the diameter of said disk is 0.23 wavelengths.
Claim 10
Dependent Claim
16 words
The combination claimed in claim 1 wherein the pitch of said helical coil is about 8°.
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) | 1979-01-12 | 1979-07-14 | 1980-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-12 | 1983-07-14 | 1984-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-12 | 1987-07-14 | 1988-01-13 | $7700.00 | Window Closed / Lapsed |