利用末端短路結構之縮小化、頻寬增益之零階共振天線設計

Abstract

本論文內容包含了兩種縮小化複合式左右手傳輸線頻寬提升設計的短路型共振天線，第一種天線利用較為窄長且複雜的設計縮減了大部分的面積使得天線面積達到極小化，第二種天線利用末端短路型的Q值關係式設計使得Q值能夠有效的降低進而使頻寬上升。 第一章以及第二章分別為緒論以及複合式左右手的基本原理介紹以及公式推導，第三章為縮小化複合式左右手末端短路之零階共振天線，利用高阻抗傳輸線與指叉式電容結構的結合，使單位結構擁有較高的串聯電容以及電桿值，並將該結構實現於RO5880 62mil基板以驗證得到反射系數定義的頻寬以及遠場輻射場形，得到3.6%的頻寬共振於2.49 GHz以及最大增計1.24 dBi與模擬非常相近驗證了這個設計的成效。 第四章為頻寬提升末端短路型之零階共振天線，透過設計較高的串聯電容以及同時降低串聯電桿值使Q值降低進而得到較佳的頻寬，同時探討單位結構內的指差式電容長度以及數量與天線頻寬的關係，最後將該結構實現於RO5880 62mil基板以驗證得到反射系數定義的頻寬以及遠場輻射場形，得到15.1%的頻寬共振於2.16GHz以及最大增益驗證了這個設計。

In this thesis, two types of improvement on Composite Right/Left Handed transmission line short-ended zeroth-order resonant antenna are presented. First unit cell of antenna combines high impedance transmission with interdigital structure so as to reduce the antenna area. The second antenna using short-ended theory and lumped elements relation with Q factor to design the Q factor of unit cell lower so as to increase the antenna bandwidth. The first and two chapters introduce the applications, operation principle and theory of CRLH-TLs and ZOR. In the third chapter, miniaturized CRLH-TLs short-ended ZOR antenna is presented. The unit cell of antenna combines high impedance transmission with interdigital structure, the unit cell has higher series capacitor and inductor and lower resonant frequency so as to reduce the antenna area. After fabricating this circuit on Rogers 5880 of 62mils, bandwidth of return loss and radiation pattern peak gain are measured 3.6% and 1.24 dBi which have good agreement. In the fourth chapter, short-ended bandwidth-enhanced ZOR antenna is presented. Using higher series capacitor and lower series inductor to decrease the Q factor so as to increasing the bandwidth. Meanwhile, research the relation between the length and number of interdigital capacitor and bandwidth of antenna to design the antenna in the best performance way. After fabricating this circuit on Rogers 5880 of 62mils, bandwidth of return loss and radiation pattern peak gain are measured 15.1% and 1.62 dBi.