US4504834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coaxial dipole antenna with extended effective aperture
Assignee: Motorola Solutions Inc
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Filing: 1982-12-22
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Granted: 1985-03-12
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Expires: 2002-12-22
Abstract
Abstract A coaxial dipole antenna includes a first radiator which is approximately one quarter wavelength long. A second radiator exhibits length less than one quarter wave length and is coupled to the feed port by a reactive element which has an electrical reactance which is insufficient to increase the electrical length of the second radiator to one quarter of the wavelength. The length of a dipole antenna is substantially shortened while an effective aperture of one half wavelength is maintained by causing a portion of the transceiver housing to radiate in phase with the antenna.
Inventors
- 👤 Oscar M. Garay
- 👤 Kazimierz Siwiak
- 👤 Quirino Balzano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:30
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/30; H01Q9/32; H01Q9/16
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
188 words
A wide bandwidth shortened dipole antenna for use with portable transceivers, comprising: a feed port including a first and a second input terminal; a first radiator coupled at one end to said first input terminal and extending outward from said feed port in a first direction, said first radiator exhibiting electrical length of approximately one quarter of a predetermined wavelength; a sleeve radiator extending outward from said feed port in a direction substantially diametrically opposed to said first direction and exhibiting electrical length less than one quarter of said wavelength; a conductor physically longer than said sleeve radiator with a portion of said conductor disposed within said sleeve radiator, said conductor being electrically attached to said second input terminal, said conductor having a predetermined capacitance between said conductor and said sleeve radiator for extending the antenna's effective radiating aperture by exciting in-phase radiation by said conductor; and a reactive element coupling the end of said sleeve radiator closest to said feed port with said second input terminal, and having an electrical reactance sufficient to increase the electrical length of said sleeve radiator to one quarter of said wavelength.
Claim 2
Dependent Claim
188 words
A wide bandwidth shortened dipole antenna for use with portable transceivers, comprising: a feed port including a first and a second input terminal; a first radiator coupled at one end to said first input terminal and extending outward from said feed port in a first direction, said first radiator exhibiting electrical length of approximately one quarter of a predetermined wavelength; a sleeve radiator extending outward from said feed port in a direction substantially diametrically opposed to said first direction and exhibiting electrical length less than one quarter of said wavelength; a conductor physically longer than said sleeve radiator with a portion of said conductor disposed within said sleeve radiator, said conductor being electrically attached to said second input terminal, said conductor having a predetermined capacitance between said conductor and said sleeve radiator for extending the antenna's effective radiating aperture by exciting in-phase radiation by said conductor; and a reactive element coupling the end of said sleeve radiator closest to said feed port with said second input terminal, and having an electrical reactance sufficient to increase the electrical length of said sleeve radiator to one quarter of said wavelength.
Claim 3
Dependent Claim
12 words
The antenna of claim 1 wherein said reactive element is an inductor.
Claim 4
Dependent Claim
16 words
The antenna of claim 1 wherein said conductor includes portions of a housing for said transceiver.
Claim 5
Dependent Claim
14 words
The antenna of claim 1 wherein said first radiator is a thin wire radiator.
Claim 6
Dependent Claim
15 words
The antenna of claim 2 wherein said inductor has the same diameter as said sleeve.
Claim 7
Dependent Claim
20 words
The antenna of claim 5 wherein said inductor is a conductive strap helix-like structure and has less than two turns.
Claim 8
Dependent Claim
13 words
The antenna of claim 6 wherein said inductor traverses approximately 426° of rotation.
Claim 9
Dependent Claim
50 words
The antenna of claim 5 further including a coaxial transmission line having an inner conductor and an outer conductor, said inner conductor attached to said first input terminal and said outer conductor attached to said second input terminal, wherein said outer conductor forms at least a portion of said conductor.
Claim 10
Dependent Claim
29 words
The antenna of claim 8 wherein the diameter of the sleeve radiator is approximately three times as large as the diameter of the outer conductor of said transmission line.
Claim 11
Dependent Claim
18 words
The antenna of claim 8 wherein said coaxial transmission line has a characteristic impedance greater than 50 ohms.
Claim 12
Dependent Claim
17 words
The antenna of claim 10 wherein the characteristic impedance of said transmission line is approximately 93 ohms.
Claim 13
Dependent Claim
19 words
The antenna of claim 8 further including a dielectric spacer disposed between said coaxial transmission line and said sleeve.
Claim 14
Dependent Claim
16 words
The antenna of claim 12 wherein said dielectric spacer has a dielectric constant of approximately 2.2.
Claim 15
Dependent Claim
20 words
The antenna of claim 13 wherein said transmission line exhibits electrical length of substantially one quarter of said predetermined wavelength.
References Cited (Backward Citations)
US282170A
Cited
US2184729A
Cited
US2311472A
Cited
DE909583C
Cited
US2492404A
Cited
US2615131A
Cited
US2648771A
Cited
US2802210A
Cited
US2825756A
Cited
US2898590A
Cited
US2828413A
Cited
US3048845A
Cited
US3089140A
Cited
US3438042A
Cited
US3576578A
Cited
US3623113A
Cited
US3818488A
Cited
US3932873A
Cited
US3980952A
Cited
US3961332A
Cited
US4097870A
Cited
US4117492A
Cited
US4205319A
Cited
US4229743A
Cited
US4204212A
Cited
US4330783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-11 | 1988-09-10 | 1989-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-11 | 1992-09-10 | 1993-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-11 | 1996-09-10 | 1997-03-12 | $7700.00 | Window Closed / Lapsed |