Study On 140GHz Y-junction Waveguide Circulator

With the accumulation of Y-junction waveguide circulator project experience and theoretical studying deeply, especially in recent years, the sucussful development of 94 GHz circulator promotes the research of the 140 GHz Y-junction waveguide circulator directly. The implementation of 140 GHz Y-junction waveguide circulator has practical significance for the development of domestic THz wireless communication system.In this paper, the research is mainly about 140 GHz Y-junction waveguide circulator. Firstly, based on its structure and working principle clearly, the engineering approximation theory and analysis of Electromagnetic Field Theory, apply to the analysis of the circulator ’s pivotal and to gain its initial value. Through the analysis of the existing literature ’s experimental results, we verify the suitability and reliability of the process, and apply the result to compute the size of ferrites. Secondly, we use the High Frequency Structure Simulator(HFSS) to model and simulate the 140 GHz Y-junction waveguide circulator with ferrite initial analytical size, then we do the optimization based on simulation results, and get the detailed impact of different ferrite radiuses, heights, relative offset from the heart of Circulator, ferrite plus cylindrical dielectric and dielectric constant of ferrite Circulator. Finally, after completing the Circulator magnetic circuit design and engineering process, building science experiment platform to measure and optimize the Circulator through the processing and analysis of the data, we get reliable results.The ultimate performance indicators of the 140 GHz Y-junction waveguide circulator are: the center frequency of 138.5GHz, the minimum Insertion Loss of 0.1d B, the maximum isolation of 22 d B. At the center frequency, the isolation is greater than 18 d B within 4GHz band, the insertion loss is less than 2d B; within 10 GHz bandwidth, isolation is greater than 15 d B, and the insertion loss is less than 2.6d B. The experimental data and simul ation results are found to be verified the correctness of the theoretical design.