EP0278069A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Near-isotropic low profile microstrip radiator especially suited for use as a mobile vehicle antenna
Assignee: Ball Corp
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Filing: 1987-11-16
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Granted: —
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Expires: 2007-11-16
Abstract
Abstract A compact, easy to manufacture quarter-wavelength microstrip element especially suited for use as a mobile radio antenna has performance which is equal to or better than conventional quarter wavelength whip-type mobile radio antennas. The antenna is not visible to a passerby observer when installed, since it is literally part of the vehicle. The microstrip radiating element (64) is conformal to a passenger vehicle, and may, for example, be mounted under a plastic roof (56) between the roof and the headliner (58).
Inventors
- 👤 Russell Wayne Johnson
- 👤 Robert Eugene Munson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 11:32
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/32; H01Q1/325; H01Q1/3275; H01Q9/00; H01Q9/04; H01Q9/0407; H01Q9/0421
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
69 words
A low profile antenna structure comprising: a first electrically conductive surface; a second electrically conductive surface substantially parallel to, opposing and spaced apart from said first surface; and transmission line means for coupling radio frequency signals to and/or from said first and second surfaces, wherein the spacing and dimensions of said first and second surfaces are selected to produce a radio frequency signal radiation pattern which is substantially isotropic.
Claim 2
Dependent Claim
69 words
A low profile antenna structure comprising: a first electrically conductive surface; a second electrically conductive surface substantially parallel to, opposing and spaced apart from said first surface; and transmission line means for coupling radio frequency signals to and/or from said first and second surfaces, wherein the spacing and dimensions of said first and second surfaces are selected to produce a radio frequency signal radiation pattern which is substantially isotropic.
Claim 3
Dependent Claim
33 words
An antenna structure as in claim 1 wherein said structure resonates at a first frequency and has a 2.0 VSWR bandwidth range of at least plus or minus 4.0% of said resonant frequency.
Claim 4
Dependent Claim
26 words
An antenna structure as in claim 1 wherein said structure has a VSWR of 2.0 or less over the range of 825 megahertz to 890 megahertz.
Claim 5
Dependent Claim
19 words
An antenna structure as in claim 1 wherein said first and second electrically conductive surfaces have substantially equal dimensions.
Claim 6
Dependent Claim
29 words
An antenna structure as in claim 1 wherein said first and second conductive surfaces are defined by a rectangular sheet of conductive material folded into the shape of "U".
Claim 7
Dependent Claim
20 words
An antenna structure as in claim 1 wherein said first and second conductive surfaces define a quarter-wavelength resonant cavity therebetween.
Claim 8
Dependent Claim
32 words
An antenna structure as in claim 1 wherein said transmission line means is connected to said first surface at a point internal to the volume disposed between said first and second surfaces.
Claim 9
Dependent Claim
25 words
An antenna structure as in claim 1 wherein said transmission line means comprises an unbalanced transmission line directly connected between said first and second surfaces.
Claim 10
Dependent Claim
36 words
An antenna structure as in claim 1 wherein said first and second surface spacing and dimensions are selected so as to produce a vertically polarized radiation pattern which is substantially omnidirectional in at least two dimensions.
Claim 11
Dependent Claim
22 words
An antenna structure as in claim 1 wherein said radiation pattern is isotropic in the plane of said first and second surfaces.
Claim 12
Dependent Claim
28 words
An antenna structure as in claim 1 wherein at least one dimension of said first surface is approximately a quarter-wavelength of the resonant wavelength of said antenna structure.
Claim 13
Dependent Claim
36 words
An antenna structure as in claim 1 further including amplifying means, disposed on said first surface and electrically connected to said transmission line means, for amplifying radio frequency signals applied to and/or received by said antenna.
Claim 14
Dependent Claim
37 words
An antenna as in claim 1 further including impedance matching means, electrically connected between said transmission line means and said first surface, for matching the impedance of said antenna with the impedance of said transmission line means.
Claim 15
Dependent Claim
111 words
An antenna structure comprising: a layer of insulative material; a sheet of conductive material folded into the shape of a U cross-section, said U-shaped sheet having first and second electrically conductive surfaces electrically connected together at respective edges thereof, said first and second surfaces being substantially parallel to and spaced apart from one another, said first and second surfaces having substantially equal dimensions and defining a quarter-wavelength resonant cavity therebetween; and means for mechanically connecting said conductive sheet to said insulative layer, wherein the spacing and dimensions of said first and second sheets are selected so that the radiation pattern of said antenna is substantially isotropic in at least two dimensions.
Claim 16
Dependent Claim
111 words
An antenna structure comprising: a layer of insulative material; a sheet of conductive material folded into the shape of a U cross-section, said U-shaped sheet having first and second electrically conductive surfaces electrically connected together at respective edges thereof, said first and second surfaces being substantially parallel to and spaced apart from one another, said first and second surfaces having substantially equal dimensions and defining a quarter-wavelength resonant cavity therebetween; and means for mechanically connecting said conductive sheet to said insulative layer, wherein the spacing and dimensions of said first and second sheets are selected so that the radiation pattern of said antenna is substantially isotropic in at least two dimensions.
Claim 17
Dependent Claim
39 words
An antenna structure as in claim 14 further including transmission line means directly electrically connected between said first and second surfaces at a point internal to said resonant cavity for coupling radio frequency signals to and/or from said sheet.
Claim 18
Dependent Claim
21 words
An antenna structure as in claim 14 wherein the spacing between said first and second conductive surfaces is approximately 1/2 inches.
Claim 19
Dependent Claim
52 words
An antenna structure as in claim 14 further including: a headliner layer spaced apart from said insulative layer, said headliner layer and insulative layer defining a chamber therebetween said folded conductive sheet being disposed within said chamber; and a further, thin conductive sheet disposed on and substantially contiguous with said headliner layer.
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