Abstract: Power is supplied to antenna elements of a helical antenna section, which are arranged at an angular distance of 90° therebetween, with a phase difference of 90°. When a reception wavelength is &lgr;, the height of the helical antenna section is 0.6 &lgr; to 0.75 &lgr;, the number of turns, T, of each antenna element is about 1, and the pitch angle &agr; of each antenna element is 50° to 60°. A straight portion with a length corresponding to ¼ of the height of the antenna section is formed at a location corresponding to ½ to ¾ of the height of the antenna section, the height of the antenna section is about 0.3 &lgr; to 0.35 &lgr;, the number of turns, T, is about 1, and the pitch angle &agr; is about 22°.