| Frequency selective surface(FSS) is a two-dimensional periodic array structure. This structure has different reflection or transmission characteristics for the electromagnetic wave of different frequencies, its essence is an electromagnetic space filter. Along with the science and technology progress and development, FSS has already been used more widely in the microwave, infrared and visible wave bands.In recent years, the scholars and research institutions at home and abroad carry on various in-depth researches and analysis to FSS, the understanding of the various characteristics of FSS is also perfect day by day. At present, how to effectively use electromagnetic wave transmission characteristics of FSS and in order to make it could better applied to practical production which has already become the main research direction of FSS. Aiming at FSS in practical application problems, the article mainly from the following several aspects launched the analysis and simulation design:1. Based on the research requirements of the Aviation Fund Project:MMW / IR imaging Dual-mode Guidance target simulation technology project, we studied and analyzed dichroic beam combiner, the key component of the mmw/ir compound guidance system, which can be realized by proper FSS. We introduced the conception and working mechanics of FSS and adopted the Floquet theorem to explain and descript the flat surface period structure including FSS. Then we discussed the factors which could affect the property of FSS and provided the common design way of FSS. A new kind of dichroic beam combiner designed by FSS is presented. The FSS using cross ring fractal element can pass through millimeter wave in 8mm and reflect infrared waves. The FSS element was arrangemented in square grid. The simulation results show that the FSS possess stable center frequency, bandwidth in different conditions of the incident wave.2. We made out the FSS by proper technique. We measured the transmissivity of the 8mm millimeter wave of the sample. And the results have been analysed deeply to find problems existing in the manufacture technique and then made out the resolutions. On the basis of consulting a large number of literature content, we analysised the reflection properties of the infrared signal of the sample theoretically and made the conclusion that the infrared reflectance could meet the project’s technical index.3. When FSS is used in dichroic beam combiner,different structure of Dielectric loaded would Influence on its performance. The article analysised the influnce on the the frequency response characteristics of FSS with different structure. After comparing the electromagnetic characteristics of three dielectric loaded structures FSS, we designed the a single layer’s dielectric-loaded double layers’ FSS aperture array structure with well performance, the simulation results showed that this structure could solve the grating lobe problems when electromagnetic wave were incidenting with large angle, which would often happen in the traditional double layers FSS structure.4. This article aims at the theory of fractal structure in application of FSS has carried on research. And with the classic "Y" pattern as an example, simulation and design their fractal structure respectively, On this basis, a kind of multi-band Y aperture FSS with a symmetry structure and anti-cross polarization is presented. Not only can it meet the requirement of dichroic beam combiner, but also it can be used in both the 8mm and 3mm mmw/ir compound guidance system, through the simulation results of detailed analysis obtained the characteristics and laws of fractal structure in application of FSS, which has certain directive significance for fractal theory in application of FSS. |
PDF Full Text Request