3D frequency selective structure

• Main Author: Wang, Yingxuan
• Other Authors: Shen Zhongxiang
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/67685
• Institution: Nanyang Technological University

This project focused on researching about designs of 3D Frequency Selective Structures with frequency filtering responses and in-band absorption performances. The basic concepts and key properties of 2D & 3D Frequency Selective Structures were studied in details for understanding. The simulation software was used to design and simulate these models and analyze the performances of different structures. The simulations were followed by analysis, parameter tunings, fabrications and measurements for the final design model. Lastly, future recommendations were discussed for better working performances and further applications. A wideband microwave absorber based on a two-dimensional periodic array of micro-strip lines was simulated via the software. Based on this model and further analysis about how the in-band frequency absorption happened, an innovative 3D dual-polarized microwave absorber was designed and simulated successfully. This innovative frequency selective absorber design model consists of periodic modified unit cells and it truly has the property of in-band frequency absorption encountering electromagnetic waves with both of horizontal polarization and vertical polarization. This 3D dual-polarized frequency selective absorber design has the frequency absorption performance with a working frequency band from 1.65 to 5 GHz. After fabrications, the absorber structure consists of 6 unit cells with the thickness of 20 mm and each unit cell has one front surface with the length of 24 mm and the width of 24 mm. Based on the simulated results, the working fractional bandwidth of this dual-polarized frequency selective absorber structure is around 100%. The measurements were conducted consequently to verify the simulated results. Finally, the absorber design model was proved with successful absorption performances when frequencies of the incident electromagnetic waves were in the working frequency band.