Coupled C-Shape Negative Refractive Index Metamaterial for Airliner Surveillance Applications

In this paper, a C-shape metamaterial (C-MTM) structure is designed for aircraft surveillance or Traffic alert and collision avoidance system (TCAS) applications. The proposed C-MTM unit-cell is a bi-layer design with inverted C shape structures placed on both the top and bottom of the FR-4 substrate material having 1.6mm thickness. The dimension of the C-MTM unit-cell is
$22\times 22mm^{2}(0.078\lambda\times 0.078\lambda)$
, with a resonating frequency of 1.06GHz. The High-Frequency Structure Simulator (HFSS) software is used to design, simulate, and evaluate the electromagnetic (EM) characteristics of the proposed MTM. The MTM unit-cell exhibit negative refractive index (NRI) and double negative (DNG) characteristics over the frequency spectrum of 0.5 to 1.2GHz. The allotted frequency band for the TCAS antenna is 960-1164MHz, since the proposed MTM shows the DNG and NRI characteristics across the entire TCAS frequency band, the designed structure is well suited for this application. A high effective medium ratio (EMR) of 12.86 clearly shows the efficacy and compactness of the proposed MTM design.