Folded spiral antenna for a portable radio transceiver and method of forming same
First Claim
1. A folded spiral antenna for a portable radio transceiver having a first end and a second end comprising:
- a ground substrate;
a first planar spiral element having a plurality of first segments for forming a first spiral radiator;
a first vertical element for connecting the ground substrate with the first planar spiral element;
a second planar spiral element having a plurality of second segments positioned in a parallel relationship to those of the plurality of first segments and forming a second spiral radiator;
a second vertical element for connecting the ground substrate with the second planar spiral element;
a shorting stub for connecting the first planar spiral element with the second planar spiral element; and
wherein the first planar spiral element and the second planar spiral element are positioned such that the second spiral radiator is positioned inside the first spiral radiator for providing a limited space antenna structure having a predetermined feed-point impedance at resonance.
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Accused Products
Abstract
A spiral antenna (100) having a feed-point end and a termination end for use within a portable two-way radio housing includes a ground substrate (102) and a number of spiral elements (103, 105) having a number of segments that form two or more spiral shapes. A shorting stub (107) connects the planar elements at a termination end for effectively increasing the feed-point impedance of the spiral antenna (100). The spiral elements (103, 105) may be positioned in a planar arrangement (FIGS. 1 and 2) or may be stacked in separate planes (FIGS. 3 and 4) for forming a limited space antenna having a substantially 50 ohm feed-point end impedance at resonance.
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Citations
36 Claims
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1. A folded spiral antenna for a portable radio transceiver having a first end and a second end comprising:
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a ground substrate; a first planar spiral element having a plurality of first segments for forming a first spiral radiator; a first vertical element for connecting the ground substrate with the first planar spiral element; a second planar spiral element having a plurality of second segments positioned in a parallel relationship to those of the plurality of first segments and forming a second spiral radiator; a second vertical element for connecting the ground substrate with the second planar spiral element; a shorting stub for connecting the first planar spiral element with the second planar spiral element; and wherein the first planar spiral element and the second planar spiral element are positioned such that the second spiral radiator is positioned inside the first spiral radiator for providing a limited space antenna structure having a predetermined feed-point impedance at resonance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A spiral antenna for use within a portable two-way radio housing having a feed-point end and a termination end comprising:
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a ground substrate; a first planar element having a plurality of first segments for forming a spiral shape; a first vertical element for connecting the ground substrate with the first planar spiral element at the feed-point end; a second planar element having a plurality of second segments positioned in a parallel relationship to the plurality of first segments; a second vertical element for connecting the ground substrate with the second planar spiral element at the feed-point end; a shorting post for connecting the first planar element with the second planar element; and wherein the first planar element and the second planar element are stacked in separate planes such that the first planar element is positioned above the second planar element for forming a limited space antenna having a substantially 50 ohm feed-point end impedance at resonance. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A spiral antenna having a feed-point end and a termination end for use within a portable two-way radio housing comprising:
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a ground substrate; a plurality of planar elements having a plurality of segments for forming a plurality of spiral radiators; a plurality of vertical elements for connecting the ground substrate with the plurality of planar elements at the antenna feed-point end; a shorting post for connecting the plurality of planar elements; and wherein the plurality of spiral radiators are stacked in separate planes such that each respective planar element of the plurality of planar elements is positioned above another respective planar element for forming a limited space antenna having a substantially 50 ohm feed-point end impedance at resonance. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of forming a spiral antenna with increased input impedance for use within a two- way radio housing comprising the steps of:
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connecting a plurality of antenna segments into a plurality spiral radiators; connecting at least one of the plurality of spiral radiators at a feed-point end to a ground substrate using at least one conductive vertical element and grounding the remainder of spiral radiators; shorting the plurality spiral radiators at a terminating end with a conductive stub; and positioning the plurality of spiral radiators above the ground substrate such that each respective one of the plurality of antenna segments is positioned outside another one of the plurality of antenna segments in a single plane and further wherein each respective one of the plurality of spiral radiators is separated by a predetermined distance from the adjacent spiral radiator for creating a limited space antenna having a substantially 50 ohm feed-point impedance at resonance. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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Specification