Patent ID: 7903030
Filing Date: 2011-03-08
Classification: H01Q

Abstract:
1. A planar antenna device, comprising: at least one antenna pair and a feed line on a dielectric board having a ground conductor on a back surface, said antenna pair including a first antenna element having a first slit, and a second antenna element having a second slit, wherein said first antenna element and said second antenna element are arranged in said planar antenna device in such a way that said first slit and said second slit are oriented toward a center of said antenna pair, said first antenna element being connected to said feed line electrically or electromagnetically at a first feeding point positioned in an inmost recess of said first slit, said second antenna element being connected to said feed line electrically or electromagnetically at a second feeding point positioned in an inmost recess of said second slit, and said first slit of said first antenna element and said second slit of said second antenna element are different in length, wherein said first slit of said first antenna element is shorter than a length from an end of said first antenna element on a side facing said second antenna to a center of said first antenna element, and said second slit of said second antenna element is longer than a length from an end of said second antenna element on a side facing said first antenna element to a center of said second antenna element, wherein said feed line feeds electrical power fed from a power feeder, to said first antenna element and said second antenna element via a branch point, and a distance from said first feeding point of said first antenna element to said branch point is approximately equal to a distance from said second feeding point of said second antenna element to said branch point, and wherein said first antenna element and said second antenna element operate at substantially the same central operating frequency.