| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna device which can receive an electric wave from a zenith direction and a horizontal direction, and whose mounting height and manufacturing cost can be each suppressed.SOLUTION: An antenna device 100 comprises: a rectangular conductor pattern 20 installed substantially in parallel to a ground plane 10 at a predetermined interval; and a short circuit part 30 electrically connected with the conductor pattern 20 and the ground plane 10; a first feeding point 40 for transmitting/receiving a signal of a first frequency; and a second feeding point 50 for transmitting/receiving a signal of a second frequency. An electrical length of one side of the conductor pattern 20 is a half of a wavelength at the second frequency. The short circuit part 30 is provided at a central part of the conductor pattern 20. An area of the conductor pattern 20 is set to such an area that an electrostatic capacitance resonates in parallel with an inductance included in the short circuit part 30 at the first frequency. |
