Study On High Performance Terahertz Passive Device

In the electromagnetic spectrum, terahertz waves have special characteristics because of its special position, which makes terahertz technology had great scientific significance and broad application prospects in many aspects. Terahertz technology has been grown up to be a hot topic research. As an important part of the terahertz system, the high-performance design and implementation have to be a very positive and important significance.This thesis focuses on the filters and directional couplers for terahertz application. Based on the practical prospects of microfabrication technology and ultra-precision machining technology, this thesis expands the research on high-performance passive devices by inspecting domestic and foreign developments. By studying the design theory of filter and directional coupler, the ultra-precision machining technology and microfabrication technology of deep reactive ion etching(DRIE) process are used to complete a high-performance and compact device design, through the accurate design. The main contents are as follows:Firstly, terahertz waveguide filters are researched.By using a variety of coupling forms, a 220 GHz waveguide filter and a 340 GHz waveguide filter with a simple structure are designed in this thesis, which have a superior performance in the low band of terahertz. The filters are fabricated using the ultra-precision machining technology. The structure of filters is integrated together with flange structure. Then a 220 GHz H plane offset inductive windows coupled rectangular waveguide filter and a 340 GHz E plane iris inductive windows coupled rectangular waveguide filter are successfully made. The S-parameters are measured by the vector network analyzer and the results are consistent with those of simulation, which indicate that the return loss is greater than 17 d B and the best insertion loss is 1 dB.Based on the technology of DRIE, a variety of coupling forms are used to design a 0.95 THz waveguide filters. The development of the 0.95 THz waveguide filter is the first time to increase the frequency to 1THz. The 0.95 THz waveguide filter has been successfully developed, which is encapsulated in the cuboid siliceous unit. For convenient testing, the supporting fixture is designed. The results are consistent with those of simulation.Secondly, terahertz waveguide directional couplers are researched.Approach of E plane at 340 GHz rectangular waveguide 10 d B directional couplers contains two options of E plane rectangular waveguide five branch lines bridge structure and E plane rectangular waveguide form of tian-shaped coupler bridge structure. Both two structures are processed by the technology of DRIE. The couplers are encapsulated in the cuboid siliceous unit. For convenient testing, the supporting fixture is designed. The results are in agreement with those of simulation.Several high-performance terahertz passive components are successfully designed and fabricated in this thesis, which have great practical value for the terahertz system research.