微帶線饋入圓極化微帶陣列天線

Abstract

由於可以降低多重路徑反射和干擾，圓極化的技術被廣泛的應用於微米波頻段。微帶天線也因為它的輕薄、短小、架構簡單和易於與其他電路結合的優點而被大家所熟知。但是，微帶天線有一個不被大家所喜愛的缺點，就是它的頻寬非常的窄，這個缺點同時也嚴重地限制了微帶天線的應用。 爲了要克服微帶天線的窄頻的缺點，吾人採用了循序旋轉的饋入技術，這個技術不但改進了微帶天線的阻抗頻寬，同時也增加了它的圓極化頻寬。 在這篇論文中，幾種利用了循序旋轉饋入技術的圓極化微帶陣列天線被提出，這幾種天線都有寬頻和高增益的優點。同時也擁有圓極化天線和微帶天線的優點，並且非常適用於高頻(微波，毫米波)頻段。

Because of its ability of reducing the multipath reflections and several kinds of interference, circular polarization (CP) has been widely used in many applications of microwave frequencies recently. Microstrip antennas are also widely known of their advantages like low profile, light weight, simple structure, and easy to integrate with other circuits. However the narrow bandwidth is an undesirable disadvantage that limits seriously the application of the microstrip antenna. In order to overcome this undesirable disadvantage of microstrip antenna, sequentially rotated feeding technique is used to increase both the impedance bandwidth and the axial ratio bandwidth. In this thesis, several kinds of wide-bandwidth and high-gain circularly polarized patch array antenna with sequentially rotated feeding technique fed by the microstrip line are presented. They preserve both the advantages of the circular polarization and the microstrip antenna, and are very suitable for microwave and millimeter-wave applications.