Antenna apparatus
AssigneeKabushiki Kaisha Toshiba
InventorsTasuku Morooka, Hisao Iwasaki, Toshiyuki Haga, Yasushi Iitsuka
Life of this patent
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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 λ, the height of the helical antenna section is 0.6 λ to 0.75 λ, the number of turns, T, of each antenna element is about 1, and the pitch angle α 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 λ to 0.35 λ, the number of turns, T, is about 1, and the pitch angle α is about 22°.
Claims9
An antenna apparatus comprising:
- a base plate having one surface provided with a ground conductor;
- a helical antenna section attached to the base plate and provided with an n-number of antenna-elements helically formed at an angular distance of (360/n)° therebetween, each antenna element including a straight portion extending parallel to the axis of the helical antenna section;
- and
- a radio frequency signal supplier which is provided on the other surface of the base plate and supplies power to the n-number of antenna elements of the helical antenna with a phase difference of (360/n)°;
- said straight portion having a lenath corresponding to about one-fourth of the height of the helical antenna section.
Dependencies are inferred from the claim text.