Patent ID: 7956815
Filing Date: 2011-06-07
Classification: H01Q

Abstract:
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, 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.