Patent US3818488A successfully refreshed from Google Patents.
US3818488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shipboard yardarm half-wave antenna
Assignee: TDK Micronas GmbH
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Filing: 1973-01-18
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Granted: 1974-06-18
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Expires: 1993-01-18
Abstract
Abstract Two frequency-adjustable antennas of the type having a helix and cylinder coaxially arranged end-to-end are themselves arranged inversely end-to-end in a 1/2 -wave dipole antenna arrangement that is entirely ground plane independent. The end-to-end radiators are arranged about a common drive means which, while providing the main structural support of the antenna arrangement, provides simultaneous synchronous tuning of each leg of the antenna arrangement.
Inventors
- 👤 C Majkrzak
- 👤 M Polgar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:10
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/06; H01Q9/14; H01Q1/00; H01Q1/27; H01Q1/34
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
149 words
A 1/2 -wave dipole antenna arrangement comprising a frequency-adjustable helix/cylinder type antennas arranged endto-end inversely along a principal axis, and means arranged between said helix/cylinder radiators for providing simultaneous synchronous tuning thereof to the same desired resonant frequency of operation from a common drive source; and wherein each said helix/cylinder radiator includes a like-wound helix arranged to have its longitudinal dimension along said principal axis and one end thereof proximate said common drive means, a cylindrical capacitive portion also arranged with its longitudinal dimension along said principal axis and having one end thereof proximate the other end of the associated helix, and shorting means of predetermined length arranged to be movable inside the associated cylindrical capacitive portion and helix and to be in continual contact therwith, for changing the resonant frequency of operation in accordance with a corresponding change in position of said shorting means along said principal axis.
Claim 2
Dependent Claim
149 words
A 1/2 -wave dipole antenna arrangement comprising a frequency-adjustable helix/cylinder type antennas arranged endto-end inversely along a principal axis, and means arranged between said helix/cylinder radiators for providing simultaneous synchronous tuning thereof to the same desired resonant frequency of operation from a common drive source; and wherein each said helix/cylinder radiator includes a like-wound helix arranged to have its longitudinal dimension along said principal axis and one end thereof proximate said common drive means, a cylindrical capacitive portion also arranged with its longitudinal dimension along said principal axis and having one end thereof proximate the other end of the associated helix, and shorting means of predetermined length arranged to be movable inside the associated cylindrical capacitive portion and helix and to be in continual contact therwith, for changing the resonant frequency of operation in accordance with a corresponding change in position of said shorting means along said principal axis.
Claim 3
Dependent Claim
25 words
The antenna arrangement according to claim 1 wherein said common drive tuning means includes means for securing the antenna arrangement to a ship''s mast structure.
Claim 4
Dependent Claim
30 words
The antenna arrangement according to claim 1 wherein said common drive means further includes an antenna mount and casing assembly to which are mounted the end-to-end inversely arranged helix/cylinder radiators.
Claim 5
Dependent Claim
86 words
The antenna arrangement according to claim 3 wherein said common drive means further includes, inside said mount and casing assembly, a remotely controllable motor controlling a common drive gear by way of the drive shaft of the former, said common drive gear being in mesh arrangement with a pair of bevel gears arranged to be facing each other and positioned at right angles to said common drive gear, the combined drive motor and gear arrangement providing simultaneous synchronous adjustment of the resonant frequency of each radiator.
Claim 6
Dependent Claim
43 words
The antenna arrangement according to claim 4 further comprising a radome portion surrounding the helix of each radiating half of the antenna arrangement, which randome portions each communicate at one end thereof with the mount and casing assembly of said common drive means.
Claim 7
Dependent Claim
33 words
The antenna arrangement according to claim 4 wherein said bevel gears are mounted on respective dielectric drive shafts communicating with said adjustable shorting means associated therewith for adjusting the resonant frequency of operation.
Claim 8
Dependent Claim
50 words
The antenna arrangement according to claim 6 wherein each said shorting means comprises a metallic shorting tube of substantially right cylindrical shape and having at each end a coaxially mounted disc-shaped shorting brush extension for providing said continual contact respectively with said cylindrical capacitive portion and said helix associated therewith.
Claim 9
Dependent Claim
31 words
The antenna arrangement according to claim 7 wherein said dielectric shafts communicate with said respective shorting means by way of at least one drive spline arrangement arranged on said shorting tubes.
Claim 10
Dependent Claim
28 words
The antenna arrangement according to claim 8 wherein said drive spline arrangement of each said shorting tube is included as part of one of said disc-shaped shorting brushes.
Claim 11
Dependent Claim
71 words
The antenna arrangement according to claim 1 wherein RF signal energy is coupled between the antenna arrangement and an RF transmission line by way of a coaxial connection mounted through a side of the antenna mount and casing assembly of said common drive means, said coaxial connection being electrically coupled to a common feed point whereat the signal energy divides to be fed to each radiating half of the antenna arrangement.
Claim 12
Dependent Claim
62 words
The antenna arrangement according to claim 10 wherein the divided signal energy is fed to the respective helix portions of the two radiating halves of the antenna arrangement by way of respective adjustable taps, arranged to be movable along the helix associated therewith in a selection of a particular helix turn to thereby provide an impedance match with said RF transmission line.
Claim 13
Dependent Claim
67 words
The antenna arrangement according to claim 1 surther comprising a pair of disc-shaped supplementary capacitive members mountable on the free end of the respective cylindrical capacitive portions of the two radiating halves of the antenna arrangement, each said member by way of its shape serving also the function of a corona cap for discouraging corona discharge from the associated cylindrical capacitive portion to other structure arranged nearby.
Claim 14
Dependent Claim
56 words
The antenna arrangement according to claim 1 further including a dielectric slug tuning means, movably arranged to be inserted in the axially direction into the end of the helix portion of each said helix/cylinder radiator nearest said common tuning means, for finely controlling impedance match of the antenna arrangement in vernier fashion through continuous adjustment capability.
References Cited (Backward Citations)
US1911234A
Cited
US3623113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |