A fast, straightforward, and accurate computer-aided design for highly efficient metasurface-assisted Fabry-Perot cavity antennas based on the equivalent circuit approach

In this paper, a fast, robust and accurate computer-aided procedure for design and analysis of highly efficient metasurface-assisted Fabry-Perot cavity antennas (FPCAs) is proposed. The automatic design algorithm is based on the equivalent circuit model (ECM) and it is capable of predicting the performances of FPCAs whose lateral walls are covered with a perfect electric conductor (PEC). In addition, it wipes out the computational burden arising from trial-and-error steps appearing in the conventional design techniques. As a prototype, according to the proposed design algorithm, a high gain FPCA with extremely high aperture efficiency is designed and fabricated for wireless applications. The equivalent circuit of the employed metasurface-based PRS is modified to enhance the accuracy of extracting the phase and magnitude of its reflection coefficient. To obtain the structural parameters of PRS, a hybrid optimization is applied to the proposed ECM. Simulated results show a maximum directivity of 18.6 dBi at 5.8 GHz leading to a high aperture efficiency of 126%. Experimental measurements on the fabricated prototype are also presented and the results confirm the theoretical and numerical predictions. The proposed design method is general and can be extended for other similar FPCA types exhibiting dual-, multi- and wideband performances. (C) 2018 Elsevier GmbH. All rights reserved.