The Design of Ring Microstrip Antennas for Circular Polarization

• Main Authors: Kuang-Woei Lin, 林光偉
• Other Authors: Desmond Sim
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/82171688212871143701

碩士 === 建國科技大學 === 機電光系統研究所 === 93 === This proposal presents the designs of a single-feed ring microstrip antenna with circular polarization (CP). Because the ring microstrip antenna has a smaller patch size comparing to the other shapes of microstrip antenna for a fixed operating frequency, it is attractive for the present wireless system. The proposal is mainly divided into three topics. First, for an annular-ring microstrip antenna, the CP radiation is excited by placing a L-shaped strip connected to two orthogonal sides of the inner boundary of the annular-ring patch. Secondly, the corner-trnucated technique is applied to a square-ring microstrip antenna. When the square-ring microstrip antenna with a narrow ring strip and thick substrate would be encountered the problem of the impedance missmatch. The impedance problem can be solved by the two technologies: using capacitively coupling feed and changing the inner slot size. Finally, the effects of the superstrate on the CP performance for the square-ring microstrip antennas are studied experimentally. All of the simulated results for the studied antennas, such as 10-dB return loss, impedance bandwidth, and 3 dB CP bandwidth obtained from the electromagnetic software IE3DTM , will be compared with the experimental results.