EP0655797A1
Expired / Lapsed
EP
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Quarter-wave gap-coupled tunable strip antenna
Assignee: Motorola Solutions Inc
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Filing: 1994-11-10
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Granted: —
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Expires: 2014-11-10
Abstract
Abstract An antenna has a quarter wave resonant strip (10) and first and second parasitically excited strips (12 and 14) resonant at a lower and upper frequency, respectively, of the antenna bandwidth. The strips (10, 12 and 14) have trim tabs (20, 22 and 24) for adjusting the resonant frequency of each strip. The location of a feed (30) is set to provide a desired impedance match for use by a radio (60) such as a pager. A ground plane (40) provides a grounding for the strips (10, 12 and 14) and inhibits undesirable radio frequency interaction between the radio (60) and the strips (10, 12 and 14).
Inventors
- 👤 Dennis Burrell
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 18:40
CPC Classifications
H; H01; H01Q; H01Q19/00; H01Q19/005; H01Q1/00; H01Q1/12; H01Q1/22; H01Q1/24; H01Q1/241; H01Q1/242; H01Q1/243
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
In a miniature radio device capable of receiving signals in a first frequency band, transmitting signals in a second frequency band, an antenna comprising: a substrate having a first planar surface and a second planar surface; a ground plane affixed to the second planar surface of the substrate; a driven resonant strip affixed to the first planar surface; at least a first parasitic strip affixed to the first planar surface and spaced a predetermined distance from the driven resonant strip; the predetermined distance being such that the first parasitic strip is capacitively coupled to the driven resonant strip to such a degree that the bandwidth of the antenna for transmission and reception encompasses the first and second frequency bands.
Claim 2
Dependent Claim
79 words
The antenna of claim 1, and further comprising: a second parasitic strip affixed to said first planar surface and spaced from the driven resonant strip by said predetermined distance; the predetermined distance separating the driven resonant strip and both parasitic strips being such that the first and second parasitic strips are capacitively coupled to the driven resonant strip to such a degree that the bandwidth of the antenna for transmission and reception encompasses the first and second frequency bands.
Claim 3
Dependent Claim
27 words
The antenna of claim 2, wherein the first and second parasitic strips have quarter wave resonant lengths at upper and lower frequencies of operation of the antenna.
Claim 4
Dependent Claim
20 words
The antenna according to claim 1 wherein said driven resonant strip and said first parasitic strip are quarter wave resonant.
Claim 5
Dependent Claim
20 words
The antenna according to claim 1 wherein said driven resonant strip and said first parasitic strip are half wave resonant.
Claim 6
Dependent Claim
52 words
The antenna according to claim 1 further comprising: a plurality of trim tabs for adjusting a resonant frequency of the antenna, wherein a first of said plurality trim tabs is attached to said driven resonant strip, and a second of said plurality of trim tabs is attached to said first parasitic strip.
Claim 7
Dependent Claim
41 words
The antenna according to claim 6 wherein said driven resonant strip is substantially rectangular and has a first side, and said first parasitic resonant strip is adjacent to the first side and spaced from the first side by the predetermined distance.
Claim 8
Dependent Claim
55 words
The antenna according to claim 7 further comprising: a plate for coupling said driven resonant strip to said first parasitic strip, said plate overlapping and parallel to both said driven resonant strip and said first parasitic strip; and an insulator substrate interposed between said plate and said driven resonant strip and said first parasitic strip.
Claim 9
Dependent Claim
61 words
The antenna according to claim 1 wherein said driven resonant strip and said first parasitic strip are substantially rectangular and have a first end adjacent to a first edge of said substrate, the antenna further comprising: a grounding means for electrically coupling the first end of each of said driven resonant strip and said first resonant strip to said ground screen.
Claim 10
Dependent Claim
37 words
The antenna according to claim 9 further comprising a feed coupled at a first end to said driven resonant strip and having a second end for coupling to a radio receiver circuit affixed to said ground screen.
Claim 11
Dependent Claim
25 words
The device according to claim 1 further comprising: a radio receiver circuit coupled to the antenna for receiving radio frequency signals received by the antenna.
Claim 12
Dependent Claim
16 words
The device according to claim 11 wherein said radio receiver circuit is a selective call receiver.
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GB2067842A
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EP0361417A2
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US4940963A
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WO1991012637A1
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