EP0359361A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Retractable cellular antenna
Assignee: Alliance Res Corp
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Filing: 1989-06-20
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Granted: —
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Expires: 2009-06-20
Abstract
Abstract An antenna assembly (10) for use on a vehicle includes telescoping radiating sections (14, 18) that collapse toward an insulated mounting base (20), so that the radiating sections can be selectively extended. An impedance matching network (22) with concentric outer (24) and inner (26) conductive tubular members slidably receives the telescopically collapsed radiating sections. Both tubular members are attached to the mounting base (20) and electrically insulated therefrom and from each other. The inner tubular member (26) is electrically connected to the radiating sections (14, 18) at a base (30) end thereof. The outer tubular member (24) has at least one longitudinal slot (32) therein through which the central conductor (42) of a transmission line is connected to the inner member. A ground contact (44) is electrically connected to the outer tubular member. A slidable terminal (36) that is selectively adjustable longitudinally along the outer tubular member is connected to the transmission line to select a signal insertion point.
Inventors
- 👤 Tetsuo Shimazaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 20:38
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/32; H01Q1/08; H01Q1/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
147 words
A vehicle antenna assembly (10) characterised by an elongate radiating section (12) mounted in relation to an insulated mounting base (20) for selective movement between an extended position and a retracted position; impedance matching means (22) mounted to the base (20) and including capacitatively coupled outer (24) and inner (26) conductive tubular members positioned at least partially to receive therein the radiating section in its retracted position, the impedance matching means having an impedance which varies along its length from a first impedance adjacent a base (30) of the radiating section, at which point the radiating section is electrically connected to the inner tubular member, and a second, lower, impedance; and coupling means (36) for connecting a transmission line to the impedance matching means (22), the position of the coupling means being adjustable along the impedance matching means, so permitting a desired matching impedance to be selected.
Claim 2
Dependent Claim
147 words
A vehicle antenna assembly (10) characterised by an elongate radiating section (12) mounted in relation to an insulated mounting base (20) for selective movement between an extended position and a retracted position; impedance matching means (22) mounted to the base (20) and including capacitatively coupled outer (24) and inner (26) conductive tubular members positioned at least partially to receive therein the radiating section in its retracted position, the impedance matching means having an impedance which varies along its length from a first impedance adjacent a base (30) of the radiating section, at which point the radiating section is electrically connected to the inner tubular member, and a second, lower, impedance; and coupling means (36) for connecting a transmission line to the impedance matching means (22), the position of the coupling means being adjustable along the impedance matching means, so permitting a desired matching impedance to be selected.
Claim 3
Dependent Claim
50 words
An antenna assembly as claimed in Claim 1 in which the elongate radiating section (12) comprises a first elongate member (14) and a second, tubular elongate member (18) electrically connected through a phasing coil (16) with the first member, the two members being arranged in telescoping relation to one another.
Claim 4
Dependent Claim
33 words
An antenna assembly as claimed in Claim 2 in which the first member (14) is substantially a five-eights wavelength radiating section and the second member (18) is substantially a half wavelength radiating section.
Claim 5
Dependent Claim
57 words
An antenna assembly as claimed in any one of the preceding claims in which the coupling means (36) has a main electrical contact (42) which is electrically connected to the inner tubular member (26) through an aperture in the outer tubular member, and a ground contact (44) which is electrically connected to the outer tubular member (24).
Claim 6
Dependent Claim
23 words
An antenna assembly as claimed in Claim 4 in which the said aperture in the outer tubular member comprises a longitudinal slot (32).
Claim 7
Dependent Claim
30 words
An antenna assembly as claimed in Claim 5 including a further longitudinal slot (34) on the opposite side of the outer tubular member (24) from the said longitudinal slot (32).
Claim 8
Dependent Claim
34 words
An antenna assembly as claimed in any one of the preceding claims including electrical motor means (48) selectively operable to effect movement of the elongate radiating section (12) between its extended and retracted positions.
Claim 9
Dependent Claim
18 words
An antenna assembly as claimed in Claim 1 in which the elongate radiating section (12) is voltage fed.
Claim 10
Dependent Claim
24 words
An antenna assembly as claimed in Claim 8 in which the elongate radiating section (12) is substantially an integral multiple of a half wavelength.
Claim 11
Dependent Claim
21 words
An antenna assembly as claimed in Claim 1 in which the length of the elongate radiating section (12) is current fed.
Claim 12
Dependent Claim
28 words
An antenna assembly as claimed in Claim 10 in which the length of the elongate radiating section (12) is substantially an odd integral multiple of a quarter wavelength.
Claim 13
Dependent Claim
31 words
An antenna assembly as claimed in any one of the preceding claims in which the inner tubular member (26) of the impedance matching means (22) is substantially one-quarter wavelength in length.
Claim 14
Dependent Claim
52 words
An antenna assembly as claimed in any one of the preceding claims including a transmission line for connection between the coupling means (36) and a radio communications unit, the transmission line having an impedance orders of magnitude less than the impedance of the elongate radiating section (12) at the base (30) thereof.
Claim 15
Dependent Claim
48 words
An antenna assembly as claimed in any one of the preceding claims in which the impedance of the assembly (10) at the coupling means (36) is substantially 50 ohms, and the impedance of the radiating section (12) at the base (30) thereof is in excess of 50 ohms.
References Cited (Backward Citations)
FR869186A
Cited
US2644089A
Cited
DE1684629U
Cited
US3798654A
Cited
US4041498A
Cited
GB1527800A
Cited
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