以金屬波導分歧結構與基板整合波導Riblet短槽結構實現W頻段垂交混成器

Abstract

本論文使用兩種不同的結構以及不同的製程來實現在特高頻(EHF)的垂交混成器，第一種是用矩形金屬波導來達到90度五階分歧耦合器的效能，透過數值矩陣分析電路並考慮波導E-平面T-接面的效應來獲取電路初步的電路參數，可以縮短電磁模擬軟體嘗試與錯誤的時間，而此金屬波導其輸入輸出波導為標準W-頻段的WR-10波導。第二種則是用基板整合波導來完成Riblet短槽式垂交混成器，並且使用扇形轉換器來進行特高頻探針的量測，其中基板整合波導使用的基板為厚度5mil損耗較低的介電常數2.2 的Rogers RT-Duroid 5880TM板材，而扇形探針轉換器則是採用適合特高頻晶圓探針機台量測之陶瓷基板，厚度同為5mil，介電常數9.8。完善的組裝兩種板材可得到正確的測量結果。以上兩種混成器電路其中心頻都是在90GHz且設計的頻寬皆在15%以上，並且皆是以能夠跟平面式電路作為整合而設計，故第一種金屬波導設計為E-平面電路，以配合E-平面探針到微帶線轉換器，而第二整基板整合波導則設計為H-平面電路，可直接與微帶線電路匹配。

In this thesis, W-band quadrature hybrids are proposed using two different structures and manufacturing processes. The first circuit is a metallic rectangular waveguide five-branch 90o branch-line coupler. By means of analytical calculation of circuit matrix including the equivalent circuit of waveguide E-plane T-junction to obtain the initial circuit parameters, the iteration time of electromagnetic simulation can be largely reduced. The I/O waveguide is the standard WR-10 W-band waveguide. The second circuit is a substrate integrated waveguide (SIW) Riblet short-slot quadrature hybrid. A fan-shaped transition is applied to meet the on-wafer probe measurement environment in the extra-high frequency (EHF) band. The SIW is manufactured on a Rogers RT-Duroid 5880TM substrate with a low loss dielectric constant of 2.2, thickness of 5mil whereas the fan-shaped transition is implemented on an Al2O3 substrate with a dielectric constant of 9.8 and thickness of 5mil. A precisely assembling of transition and SIW hybrid is extremely important for a proper measurement results. Both two kinds of hybrid circuits are designed at the center frequency of 90GHz and a fractional bandwidth more than 15%. Meanwhile, both circuits are design to integrate with microstrip planar circuit. The first circuit is an E-planar circuit that it matches with an E-plane probe to microstrip transition. And the second circuit is an H-plane SIW that it is inherently applying the microstrip as the I/O transmission lines.