Low-profile antenna structure
First Claim
1. An antenna structure comprising:
- two excited elements that are (i) low-profile inverted-F antennas and (ii) arranged on a ground plane in such a manner that, out of an x-axis and a y-axis that perpendicularly intersect with each other at an origin of the xy-axes on the ground plane, the two excited elements are on the x-axis, one in a positive and the other in a negative direction of the x-axis;
two parasitic elements that are (i) low-profile inverted-F antennas and (ii) arranged on the ground plane in such a manner that the two parasitic elements are on the y-axis, one in a positive and the other in a negative direction of the y-axis;
two feed units each of which has been connected to and feeds a signal to a different one of the two excited elements, in such a manner that phases of the signals to be fed to the two excited elements are different from each other by a desired degree; and
two variable reactors each of which (i) is connected to a different one of the two parasitic elements and (ii) in accordance with a reactance value thereof, changes an electrical length of the corresponding one of the two parasitic elements, whereinthe two excited elements and the two parasitic elements have the same outer dimension and are at an equal distance from the origin of the xy-axes.
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Accused Products
Abstract
A low-profile antenna structure can control its directivity with great flexibility. Excited elements 11 and 12 are symmetrically arranged on a y-axis, whereas parasitic elements 13 and 14 are symmetrically arranged on an x-axis, with respect to an origin. The excited elements, as well as the parasitic elements, each have an inverted-F antenna structure and are a distance of λ/4 apart from each other. Feed circuits 21 and 22 are respectively connected to and feed signals to the excited elements 11 and 12, such that phases of the signals to be fed are different from each other by a desired degree. Variable reactors 23 and 24 (i) are respectively connected to the parasitic elements 13 and 14, and (ii) in accordance with reactance values thereof, can each change an electrical length of the corresponding one of the parasitic elements.
24 Citations
10 Claims
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1. An antenna structure comprising:
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two excited elements that are (i) low-profile inverted-F antennas and (ii) arranged on a ground plane in such a manner that, out of an x-axis and a y-axis that perpendicularly intersect with each other at an origin of the xy-axes on the ground plane, the two excited elements are on the x-axis, one in a positive and the other in a negative direction of the x-axis; two parasitic elements that are (i) low-profile inverted-F antennas and (ii) arranged on the ground plane in such a manner that the two parasitic elements are on the y-axis, one in a positive and the other in a negative direction of the y-axis; two feed units each of which has been connected to and feeds a signal to a different one of the two excited elements, in such a manner that phases of the signals to be fed to the two excited elements are different from each other by a desired degree; and two variable reactors each of which (i) is connected to a different one of the two parasitic elements and (ii) in accordance with a reactance value thereof, changes an electrical length of the corresponding one of the two parasitic elements, wherein the two excited elements and the two parasitic elements have the same outer dimension and are at an equal distance from the origin of the xy-axes. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An antenna structure comprising:
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n low-profile excited elements, n being an integer equal to or greater than 2; n low-profile parasitic elements; n feed units each of which has been connected to and feeds a signal to a different one of the n excited elements, in such a manner that phases of the signals to be fed to the n excited elements are different from each other by a desired degree; and n variable reactors each of which (i) is connected to a different one of the n parasitic elements and (ii) in accordance with a reactance value thereof, changes an electrical length of the corresponding one of the n parasitic elements, wherein provided that a polygon having 2n vertices is plotted on a ground plane and that the vertices are numbered clockwise starting at one of the vertices, each excited element is arranged on a different one of the vertices that are odd-numbered, whereas each parasitic element is arranged on a different one of the vertices that are even-numbered, and at least one of the excited elements and the parasitic elements is an inverted-L antenna, a T antenna or a patch antenna. - View Dependent Claims (9, 10)
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Specification