Equivalent pattern modeling method of periodic pattern surface and its application to the broadband radar absorbing sandwich structure

Abstract

From a practical point of view, a broadband radar absorbing sandwich structure (RAS) consisting of a glass fiber reinforced polymer (GFRP), a foam core, and a periodic pattern surface (PPS) was developed using the proposed equivalent pattern modeling method (EPMM). As implementable sheet resistance is limited by the electrical properties of conductive ink and the fabrication method, the design flexibility of PPS can be reduced. The EPMM allows a more flexible design with limited sheet resistance values. Using the EPMM, the initial pattern design with a sheet resistance was replaced with an implementable sheet resistance and a modified pattern. The – 10 dB bandwidth of the broadband RAS, which is designed using an equivalent pattern converted through the EPMM, was about 10 GHz. To demonstrate the proposed design method, the designed broadband RAS was fabricated using an autoclave process and measured using a free-space measurement system. The measurement result was well matched with the design, and the EPMM was confirmed to work well. From this study, it was confirmed that the proposed EPMM could extend the implementable range of sheet resistance that can be implemented as a material, thereby contributing to the implementation of more practical and high performance RAS.