This paper introduces an array with a new element structure to achieve asymmetric sidelobe pattern nulling which is a much desired feature in many applications such as communication systems, tracking radars, and imaging. The proposed element structure consists of combining two simple wire dipoles in the horizontal and vertical positions to form a crossed dipole element. The array patterns of the horizontal and vertical dipoles alone share some common radiation feature such angular null positions which are exploited to provide sidelobe nulling. By properly scaling the array pattern of the horizontal dipoles and added or subtracted its array pattern from that of the vertical dipoles, a new array pattern corresponds to the crossed dipoles elements with controlled sidelobes pattern can be obtained. The scaling factor selects which sidelobes to be cancelled. The method is equally applied to the uniformly and nun-uniformly excited arrays. The proposed idea is verified by simulating an array with 10 half wavelength crossed dipoles using CST microwave studio.
Key words: Antenna arrays, Two crossed dipole elements, Asymmetric sidelobe pattern nulling.
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