Patent US1151843A successfully refreshed from Google Patents.
Patent EP0718909A2 successfully refreshed from Google Patents.
EP0718909A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Retractable top load antenna
Assignee: Nokia Oyj
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Filing: 1995-11-24
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Granted: —
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Expires: 2015-11-24
Abstract
Abstract An antenna assembly comprises an elongate antenna element (11) mounted in a support (5) and movable between a retracted position and an extended position. A helical antenna element (12) in electrical contact with the helical element is carried at one end of the elongate element. The coupling between the feed point and the antenna in the retracted and extended positions allow the same matching circuitry to be used in both conditions. The invention provides a compact and convenient dual antenna arrangement ideally suited for use in a portable cellular radio telephone.
Inventors
- 👤 Brian James Davidson
- 👤 Stephen Goodwin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 01:30
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/30; H01Q1/00; H01Q1/12; H01Q1/22; H01Q1/24; H01Q1/241; H01Q1/242; H01Q1/243; H01Q1/244; H01Q1/36; H01Q1/362
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
An antenna assembly comprising an elongate antenna element mounted in a support and movable between a retracted position and an extended position, a helical antenna element in electrical contact with, and carried by, the elongate antenna element, means for feeding the elongate antenna in the extended position from an end remote from the helical antenna, means for grounding the helical antenna in the retracted position at a ground point adjacent the elongate antenna element such that currents are substantially inhibited in the elongate element in the retracted position, and means for feeding the helical element in the retracted position.
Claim 2
Dependent Claim
38 words
An antenna assembly according to claim 1 wherein the the means for feeding the helical element comprises a reactive coupling such that the impedance at a feed point in the retracted and the extended positions is substantially equivalent.
Claim 3
Dependent Claim
25 words
An antenna assembly according to claim 2 wherein signals are fed to and received from the feed point in both the retracted and extended positions.
Claim 4
Dependent Claim
17 words
An antenna assembly according to claim 2 or 3 wherein the reactive coupling is an inductive coupling.
Claim 5
Dependent Claim
27 words
An antenna according to any one of claims 2 to 4 wherein the reactive coupling comprises a tap coupled to a tapping point on the helical element.
Claim 6
Dependent Claim
19 words
An antenna assembly according to claim 5 wherein the helical element is wound more tightly below the tapping point.
Claim 7
Dependent Claim
31 words
An antenna assembly according to any one of claims 2 to 4 wherein the reactive coupling comprises a second helical element wound in the opposite sense to the first helical element.
Claim 8
Dependent Claim
52 words
An antenna assembly according to any one of claims 2 to 7 wherein the reactive coupling comprises a conductive member carried by the helical element and wherein a cooperating conductive member carried by the support is arranged for coupling to the conductive member carried by the helical element in the retracted position.
Claim 9
Dependent Claim
22 words
An antenna assembly according to claim 8 wherein the conductive member is configured to form a collet depending from the helical element.
Claim 10
Dependent Claim
16 words
An antenna assembly according to claim 8 wherein the conductive member is a spring loaded pin.
Claim 11
Dependent Claim
25 words
An antenna assembly according to any one of claims 2 to 10 wherein a capacitance to ground is provided in parallel with the reactive coupling.
Claim 12
Dependent Claim
33 words
An antenna assembly according to claim 11 wherein the capacitance to ground is provided by a coaxial transmission line with the central conductor grounded and the outer conductor coupled to the reactive coupling.
Claim 13
Dependent Claim
35 words
A portable radio transceiver comprising a housing enclosing transmitting and receiver circuitry, and an antenna assembly as claimed in any of the preceding claims, said antenna assembly being coupled to said transmitting and receiving circuitry.
Claim 14
Dependent Claim
38 words
An antenna according to any preceding claim wherein the means for grounding the helical antenna comprises means for coupling the elongate antenna to ground at a position approaching the end of the elongate antenna adjacent the helical element.
Claim 15
Dependent Claim
26 words
An antenna assembly according to claim 2 wherein the elongate antenna is further grounded in the retracted position at the end remote from the helical element.
References Cited (Backward Citations)
US4868576A
Cited
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