Patent ID: 8077115
Filing Date: 2011-12-13
Classification: H01Q

Abstract:
1. An antenna device comprising: a first antenna element which is either a spiral antenna element or a loop-like antenna element; a first feed point provided at a first end of the first antenna element, the first end being an outer end of the spiral antenna element or an one end of the loop-like antenna element, a second antenna element which is either a spiral antenna element or a loop-like antenna element; a second feed point provided at a first end of the second antenna element, the first end of the second antenna element being an outer end of the spiral second antenna element or an one end of the loop-like second antenna element; a feed line connected to the first antenna element via the first feed point: a dielectric substrate; and a resistor element; wherein a length from an second end of the first antenna element to the first end of the first antenna element along the first antenna element is about one half wavelength of operating frequency, the second end being an inner end of the spiral antenna element or the other end of the loop-like antenna element, the differential line is a parallel line formed on the dielectric substrate, the first and second signal lines have a straight line shape, respectively, the first antenna element is connected midway of the first signal line via the first feed point, the second antenna element is connected midway of the second signal line via the second feed point, and the resistor element connects the first and second signal lines included in the parallel line each other so as to connect a portion of the first signal line from one end of the first signal line to the first feed point and a portion of the second signal line from one end of the second line directed to same direction as the one end of the first signal line to the second feed point.