Design of an 3-Element Arc Array of Microstrip Antenna for Widen Bandwidth and Adjusting Beam Direction

In the detector design of RFID, radio frequency identification devices, the antenna beam needs to meet the conditions of high gain and adjustable direction to cover the room and corridor in indoor environment,. In this paper, an 3-element arc array of microstrip antenna based on circularly polarized microstrip patch antenna are studied by quasi-Newton method in HFSS(high-frequency structure simulator). In this array, three probe-fed circularly polarized microstrip patch antenna, whose working frequency is 915Mhz, is placed on an arc array and the two array elements on both sides are symmetric. It is investigated that gain and bandwidth of the antenna array can be enhanced and the beam direction can be adjusted by properly arranging these array elements. The driven patch is a perturbed square one with two diagonal corners truncated in order to realize circular polarization. The model of antenna array has a gain of 5.9dB with a 3dB axial ratio bandwidth of 23.8%. The proposed antennas have been made and measured. The experimental results are basically the same as the simulation results. The research results provide a new idea for the design of microstrip antenna array, which can obtain higher gain while adjusting the beam direction of the antenna array.