Design of CPW-Fed Circularly Polarized Slotloop Antennas

• Main Authors: Shin-Shing Jiang, 江信興
• Other Authors: Powen Hsu
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/49317974081769952788

碩士 === 國立臺灣大學 === 電信工程學研究所 === 91 === CPW-fed circularly polarized slotloop antennas are studied in this dissertation. So far, very few CPW-fed CP antennas have been presented. The reason is that the transmission mode of CPW has a strong interference on the radiator that makes the CPW-fed slotloop antenna inherently linearly polarized. To overcome this problem, we use the air bridge to connect the uniplanar ground planes on the left and right of the center conductor. For thorough investigation, we perform the parameter studies of CPW-fed perturbed slotloop antenna. Good circular polarization is obtained at the broadside direction of the antenna. In order to confirm our design, a case without air bridge is compared with the original case. A CPW-fed perturbed slotloop antenna without air bridge results in linear polarization. This outcome confirms the effect of the air bridge. We design a square and a circular perturbed slotloop antennas at the same time to ensure our design method is operative. Experimental results show that the 3dB axial ratio bandwidth of the CPW-fed perturbed slotloop antenna is about 4.11% and 5.3% for the square loop and circular loop, respectively.