US 2006/0139230 A1Published application

Antenna

AssigneeDX Antenna Company, Limited

InventorsToshiaki Shirosaka, Shingo Fujisawa

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Abstract

A transmission line includes transmission lines parallel and perpendicular, respectively, to a flat portion of a reflector, and the parallel transmission line and the flat portion form a first strip line and the perpendicular transmission line and a conductive plate similarly form a second strip line. Radiators and the transmission line have a radiation impedance and a characteristic impedance, respectively, both set at 150 Ω when the antenna's output terminal has a reference impedance of 75 Ω. If the parallel transmission line has a midpoint serving as the output terminal of the antenna this portion's receiving current is divided in two so that an impedance of half that of the strip line can be provided and a coaxial cable can directly be connected to the transmission line. A matcher or a mixer is not included in the antenna, and matching and mixing losses can be prevented.

Claims20

Dependent claims

An antenna comprising:

a reflector formed of conductor and having a flat portion reflecting a prescribed electric wave;
a first transmission line facing said flat portion with a prescribed distance therebetween;
a plurality of radiators each formed of conductor and arranged on a same side as said first transmission line relative to said flat portion, said plurality of directors each having first and second feed points arranged to have a distance from said flat portion larger than said prescribed distance;
a plurality of second transmission lines associated with said plurality of radiators, respectively, and electrically connecting said first feed point and said first transmission line together;
and
a plurality of conductive plates arranged parallel to said plurality of second transmission lines, respectively, and electrically connecting said second feed point and said flat portion together, said plurality of conductive plates, as seen along said second transmission line, having a surface facing said second transmission line and larger in width than said second transmission line.

3 more elements

Dependencies are inferred from the claim text.