Multi-band and multi-polarised reconfigurable antenna for next generation mobile communication base-station applications

A novel multi-band reconfigurable antenna for a mobile base-station is proposed. This antenna can be operated in three bands using three radiators, but the radiators are physically combined into one body in consideration of size reduction and optimal performance. Radiator 1 is a square patch structure and is operated in 0.824-0.894 GHz for cellular service. Radiator 2 provides multiple mobile services in 1.75-2.48 GHz for personal communication service (PCS), wideband code division multiple access (WCDMA), world interoperability for microwave access (WiMAX) and WiFi, and thus has a wideband characteristic using a printed dipole structure. Finally, radiator 3 has a stacked structure composed of a radiating and a parasitic patch in 3.3-3.6 GHz for WiMAX2. Radiator 1 has a cylindrical cavity in the centre of the patch, and is designed not to degrade electrical performance, and radiator 3 is embedded in the cavity of radiator 1. Radiator 2 is composed of four printed dipoles and is vertically stacked on radiator 1 around radiator 3 with a rectangular formation. All radiators can provide dual-polarisation using multi-ports controlled by a switching circuit with a control program. In the switching circuit, there are two MEMS switches for band selection. Using the proposed structure, the authors realise a novel multi-functional reconfigurable antenna using three individual radiators.