低旁波瓣寬頻緩變微帶洩漏波天線

Abstract

一般的洩漏波天線具有高增益、高輻射效率、低成本等優點。在本論文中，我們將研究寬頻第一高階模洩漏波天線。我們使用以微帶線設計非平衡-平衡電路來激發第一高階模。 反向平衡式微帶線乃利用平衡式微帶線結構而將基板上下之正負微帶位置互異而得。此反向平衡式微帶線跟平衡式微帶線結合使用則能形成兩對寬頻之非平衡-平衡電路，並用來當寬頻洩漏波天線之基本饋入結構。 根據微帶線之第一高階洩漏波特性，本文使用一演算法則來設計寬頻緩變洩漏波微帶天線。而此寬頻緩變洩漏波微帶天線反射損失的量測結果，可以看到 的頻寬從10GHz至40GHz，相對的頻寬約4:1。 最後，本文提出ㄧ新穎演算法則來設計低旁波束寬頻緩變洩漏波微帶天線。此演算法可以降低side lobe level。

Generally, leaky wave antennas have the advantages: high gain, high radiation efficiency, low cost. In this thesis, we study the first higher order mode broadband microstrip leaky-wave antennas. We will implement the first higher order mode leaky wave antenna by the broadband balun. The inverted balanced microstip line structure is developed from the balanced microstrip line. The position of the positive strip on the upper substrate side is exchanged with that of the negative strip on the lower substrate side by the method proposed in this thesis.United with the balanced microstrip line, this inverted balanced microstrip line can be used to form into a pair of broadband baluns. Using this broadband balun can realize a broadband leaky-wave antenna. Based on the characteristics of the first higher order leaky-mode for the microstrip antenna, this thesis proposes a scheme for the empirical design of broadband tapered microstrip leaky-wave antenna. The measured bandwidth of the tapered microstrip leaky-wave antenna has a from 10GHz to 40GHz, yielding a relative bandwidth of 4:1. Finally, this thesis proposes a novel scheme for the empirical design of lower sidelobe broadband tapered microstrip leaky-wave antenna.