Design of a circular disc-shaped pattern reconfigurable antenna with parasitic patch

A novel circular disc-shaped pattern reconfigurable antenna with parasitic patches is proposed in this paper.The antenna mainly consists of the central circular patch and five surrounding fan ring parasitic patches with U-shaped slot.The proposed antenna can work in the 5.5GHzWiMAX(World Interoperability for Microwave Access)frequency band and has a good performance of impedance matching at the resonant frequency.By controlling the states of five switches,the main lobe of each pattern directs to one of five different directions in the plane with the elevation angle of 4 degree.Considering the pattern gain and beam width,the antenna can cover all directions in the elevation plane.The gains of the back lobe and side lobe are both low,and the main lobe is high which gain can reach 6.3dB.A good performance of the antenna in directional radiation characteristic and interference restraining can be achieved.The designed antenna is compact in size and low in profile.The effects on the antenna performance of some important structure parameters are also analyzed in the paper.The simulation and measurement results of the proposed antenna are in a good agreement.