Characteristics of a dual-feed dipole antenna with parasitic elements

Current mobile communication systems are assigned three frequency bands in Japan. In order to deal with these frequency bands, to limit the space of the base station, and to reduce the antenna construction cost, multiresonant antennas are used in base stations in mobile communication systems. Generally, a center-feed dipole antenna (CFDA) with parasitic elements is used to construct the multiresonant antenna. This paper proposes a dual-feed dipole antenna (DFDA) with parasitic elements to reduce the size of the grating-lobes of the array antenna at the highest frequency (f_H). The proposed DFDA array suppresses the grating-lobe at the f_H, and the maximum gain of f_H is improved in comparison to the typical CFDA. Furthermore, we present the structure of a new printed DFDA that is fabricated on one dielectric substrate. The antenna characteristics are calculated by the moment method using a wire grid model.