Multi-Band Frequency Selective Surfaces: Analysis; Final rept

摘要

Present trends in antenna development go toward the integration on the same antenna aperture of more functions operating in separate frequency bands. In view of this, the necessity to look at new Frequency Selective Surface (FSS) concepts becomes evident. These structures should have pass-bands corresponding to the antenna operational frequencies sandwiched between sharp stop-bands. An advanced tool has been developed at TNO for the analysis and design of multi-layer FSSs. In the frame of Phase I of the Multiband Frequency Selective Surface project defined within the ITM programme, the tool has been upgraded with new features that allow handling new complex geometries. The tool has been equipped with a triangular mesh and the electric and magnetic currents on the FSS elements have been discretised in terms of Rao Wilton Olisson functions. Moreover, the application of the bitmapping design technique requires considering completely metallised unit cells and therefore ensuring the continuity of the currents across adjacent cells. A further upgrade in this direction has been introduced in the tool. The new implementations have been tested against results available in the open literature and the obtained agreement is very good.