Patent ID: 7701407
Filing Date: 2010-04-20
Classification: H01Q

Abstract:
1. A slot antenna apparatus comprising: a grounding conductor, having an outer edge including a first portion facing a radiation direction, and a second portion other than the first portion; a one-end-open feed slot formed in the grounding conductor along the radiation direction such that an open end is provided at a center of the first portion of the outer edge of the grounding conductor; and a feed line including a strip conductor close to the grounding conductor and intersecting with the feed slot at least a part thereof to feed a radio frequency signal to the feed slot, wherein the feed line is branched at a first point near the feed slot into a group of branch lines including at least two branch lines, and at least two branch lines among the group of branch lines are connected to each other at a second point near the feed slot and different from the first point, thereby forming at least one loop wiring line on the feed line, wherein a maximum value of respective loop lengths of the at least one loop wiring line is set to a length less than one effective wavelength at an upper limit frequency of an operating band, wherein branch lengths of all those branch lines among the group of branch lines, each branch line terminated at an open end and not forming a loop wiring line, are less than one-quarter effective wavelength at the upper limit frequency of the operating band, and wherein the slot antenna apparatus further comprises at least one one-end-open parasitic slot having an electrical length equivalent to one-quarter effective wavelength in a certain stop band, the parasitic slot having an open end at the second portion of the outer edge of the grounding conductor, and being formed in the grounding conductor so as not to intersect with the feed line.