Patent ID: 7397439

Claim:
A slot antenna comprising: a dielectric substrate; a ground conductor provided on a rear face side of the dielectric substrate, the ground conductor having a finite area; a slot which recesses into the ground conductor, beginning from an open-end point on a side edge of the ground conductor; and a feed line for supplying a high-frequency signal to the slot, the feed line at least partially intersecting the slot, wherein, at a first point near the slot, the feed line branches into a group of branch lines including at least two branch lines, such that at least two branch lines in the group of branch lines are connected to each other at a second point near the slot to form at least one loop line in the feed line, the second point being different from the first point; a maximum value of a loop length of each loop line is prescribed to be less than 1× effective wavelength at an upper limit frequency of an operating band of the slot antenna; and in the group of branch lines, any branch line that does not constitute a part of the loop line but terminates with a leading open-end point has a branch length which is less than a ¼ effective wavelength at the upper limit frequency of the operating band.