W頻段矩形波導至基板整合波導E平面轉換器

Abstract

本論文分成兩部分，第一部分為設計W-頻段的矩形波導至一般印刷電路板製成的基板整合波導之E-平面轉換器。在這篇論文當中，我們使用的板材是損耗較低的Rogers RT-Duroid 5880TM，其板材的介電常數為2.2，正切損耗為0.0009，而考慮到板材厚之度與品質因子(Q值)的關係，最終我們選用10mi厚的板材來進行模擬與實作，其轉換器最終的目的是要符合性能需求，且易於製作和組裝。第二部分則是先進行了瑞卜列特(Riblet)短槽式耦合器實現在基板整合波導之上的分析與設計，確認能量的穿透(through)與隔離度(isolation)後，再加入第一部分之轉換器做整合與量測。 由於在W-頻段當中，所有尺寸(機械、基板整合波導電路)對於最後結果兩者之間相互影響是敏感的，而其造成的影響可能是巨大的，本論文當中還進行了若基板整合波導實作與金屬矩形波導不能完美貼合等狀況的討論與模擬，也比較了其可能改進的架構與改進前後的結果。最後在實測當中用電路量測結果與模擬來進行討論兩者不同的可能原因。

This thesis contains two parts. The first part of this thesis is to design a W-band E-plane transition which guides the electromagnetic wave from the rectangular waveguide into the substrate integrated waveguide (SIW). The substrate used to implement the circuits is a low dielectric loss Roger RT-Duroid 5880TM which has a dielectric constant of 2.2, and a loss tangent of 0.0009. Considering the relationship between the substrate thickness and the unloaded quality factor value (Q-value) of the SIW resonator, a 10-mil-thick substrate is chosen. The goal of the transition is to fulfil the requirements of easy assembling and good electrical performance. The second part of thesis, we analyze and design the Riblet short slot coupler on substrate integrated waveguide. As the through and the isolation performance of the circuit are satisfied, the coupler is combined with the transition in the first part to do the measurement. In the frequency of W-band, the effect of physical dimension tolerance including the mechanical housing and the SIW could be sensitive to the circuit performance. In the thesis, we also discuss and simulate the situation when the rectangular waveguide and the SIW fit each other imperfectly and compare it with the original simulation results. In the end, we discuss and try to figure out the difference between simulation and measurement results.