EMC Research Of Carrying Platform Based On The Frequency Selective Surface Sheilding

This paper mainly studies the electromagnetic compatibility and electromagnetic susceptibility based on the carrying platform. This paper takes the domestic communication frequency(center frequency of 2GHz) as analyzed cases. Firstly, the surface current distributions of groove model, one of the most representative metal models, are analyzed under the radiation of the plane wave and the horn antenna. The conclusion is drawn that the surface current gets to the maximum by the electromagnetic radiation at 45 degrees. Furthermore, we also discuss the changes of surface current distribution under the radiation of the horn antenna before and after loading band-stop frequency selective surface(FSS)(the centre frequency of 2 GHz). After loading FSS, the metal surface electric field intensity is greatly reduced. It shows that this type of FSS has played a very important role in the related electromagnetic shielding. The shielding effectiveness of FSS is calculated and analyzed.And then, taking vehicles under the radiation with different directions and angles as analyzing models, the electromagnetic compatibility of the carrying platform is investigated in detail. The conclusion proves that the surface currents and surface electric field are concentrated near the vehicle windows, and that microwave penetrates the metal body through the window. After many times of reflections inside the vehicle, the electromagnetic waves become much more complicated, and may cause great harm on the human body, sensitive electronic equipment(system), dangerous or crucial goods, etc. After applying the FSS on vehicle windows for electromagnetic shielding, the vehicle electromagnetic environment can be significantly improved. Under the radiation of different electromagnetic waves, there is still a lot of electromagnetic wave near the windows, but the electric field intensity gets obviously reduced inside the vehicle. In the chosen of the two central axis of the body as the reference lines, the electric field distribution of the reference lines are analyzed. By comparing electric field intensities on these axis before and after loading the FSS, the shielding effectiveness is evaluated.At last, a more complicated model with background of practical applications, the high power electromagnetic compatibility of vehicle mounted antenna, is analyzed. Under normal working state of the vehicle antenna, a large number of electromagnetic waves penetrate through the windows into the cockpit and has a significant potential impact on the driver, sensitive electronic equipment(or system), dangerous or important goods, etc. After the FSS applied to the windows, the improvement of electromagnetic shielding effect is very obvious. At the same time, through employing the contrast analysis of the radiation patterns and gain of array antenna, vehicle-mounted antenna, vehicle mounted antenna with FSS, it can be known that vehicles contribute to the reduction of array antenna side-lobe and increasing the antenna gain, to some extents, and has little influence on electric field distribution on the surface of the antenna aperture,while loading the FSS does not affect vehicle antenna performance much more.