YAGI-TYPE ANTENNAS AND METHOD

摘要

This disclosure is concerned with compensating for unsymmetrical antenna receiving or transmitting patterns caused by unbalanced driven element feed, by compensatory unsymmetrical interaction with parasitic director and/or reflector elements. An improved Yagi-type antenna has, in combination, a coaxial-line-fed antenna having one portion connected to the inner line and the other portion connected to the outer line of the coaxial line and thus producing an unsymmetrical pattern. Parasitic conductive elements are spaced from but near the antenna and comprise portions corresponding to and extending substantially parallel to the portions of the antenna. The parasitic conductive element portion corresponding to the other portion of the antenna is of greater dimension than the portion corresponding to the one portion of the antenna to introduce compensatory unsymmetrical parasitic interaction to render the pattern symmetrical.