基於SU-8光阻製程技術設計之太赫茲波導帶通濾波器

Abstract

本論文旨在研究太赫茲波導濾波器的設計，並使用SU-8光阻製程，並且通過最終的量測結果以證明設計以及其製程的可行性。本論文主要分為兩部分。第一部分是濾波器的基本理論。在本節中吾人介紹了由柴比雪夫耦合矩陣合成法，將具有濾波響應的廣義柴比雪夫多項式進而合成所需的耦合矩陣，再藉由耦合共振器濾波器來實現帶通濾波響應。而第二部分則是SU-8光阻製程以及設計之濾波器結構。在此節中吾人將介紹SU-8光阻製程其步驟，並且利用SU-8之特性採用層堆疊以及T型匹配的方式來設計出一五階波導帶通濾波器以及一波導雙頻帶濾波器。 量測結果表明300 GHz波導濾波器其在295 - 325 GHz的通帶內插入損耗小於5 dB，回波損耗優於15 dB。雙頻帶濾波器在257 - 272 GHz & 294 - 310的通帶內插入損耗小於8 & 7 dB，回波損耗優於13 & 15 dB。由於這兩個濾波器的性能不盡理想，所以吾人作了後模擬以分析探討影響通帶內的插入損耗的原因，以便在後續的設計中進行修正與改進。

This thesis aims to study the design of terahertz waveguide filters using SU-8 photoresist processing and to demonstrate the feasibility of the design and its process through final measurement results. The thesis is mainly divided into two parts. The first part covers the basic theory of filters. In this section, the Chebyshev coupling matrix synthesis method is introduced. The generalized Chebyshev polynomials with filtering response are synthesized to obtain the required coupling matrix, and bandpass filtering response is achieved through coupled resonator filters.The second part focuses on the SU-8 photoresist process and the structure of the designed filters. In this section, the steps of the SU-8 photoresist process are introduced, and a five-order waveguide bandpass filter and a dual-band waveguide filter are designed using the characteristics of SU-8 through layer stacking and T-shaped matching. The measurement results indicate that the 300 GHz waveguide filter has an insertion loss of less than 6 dB within the passband of 280 - 320 GHz and a return loss better than 18 dB. The dual-band filter has an insertion loss of less than 7 dB and 7.5 dB within the passbands of 257 - 272 GHz and 294 - 310 GHz, respectively, and a return loss better than 13 dB and 15 dB. Due to the suboptimal performance of these two filters, post-simulations were conducted to analyze and investigate the causes of insertion loss within the passbands, with the aim of making corrections and improvements in subsequent designs.