Design of the dual-polarized dipole antenna for small base station

Presently, the wireless communication market is the tendency that the consumer request increases it desires the faster service with the saturation of the radio communication. In the near future, the mobile traffic increases and the new mobile service appearance are predicted. Many radio communications can be used one base station and the size small and technology considering the environment-friendly is needed. The technology generated by this request is the light-radio technology [1]. Each small-sized base station is connected to the optical cable and the speed of the light is implemented and it is called as the light-radio. The core technology for comprising light-radio is the miniaturization of the base station. It has within the RF part and antenna in one small square cube and the base station has to be miniaturized. Particularly, the miniaturization of the antenna is very important. The dual-polarized antenna using the electric and magnetic field is used [2-6]. However, it is very difficult to comprise two antennas inside the cube where there is the restriction of the space not being free space. In this paper, we have modified the dual-polarized dipole antenna of [7]. The proposed antenna had the size smaller than published paper [7] and applied inside the cube. The proposed antenna induced the coupling characteristic of the radiator and feeding line and expanded the frequency bandwidth. To antenna matching, we changed distance and width of two feed lines. We changed width of the shorting plate and length of the feed line and the operating frequency was moved. In spite of being the small sized antenna mounted inside cube, the proposed antenna obtained the wide bandwidth, the high isolation and antenna gain.