Metamaterial synthesis using a CAD model based on an evolutionary technique to improve the performance of TCAS antennas

Abstract

We propose a computer-aided design (CAD) model for synthesis of the unit cell of a metamaterial with the aim of improving the performance of a microstrip antenna designed for use in a traffic collision avoidance system (TCAS). Synthesis of electromagnetic (EM) devices generally requires great computational resources because of their inherent properties, e.g., being complex, nonconvex, and continuous. However, techniques based on soft computing are much more convenient for problems related to such EM devices. In this work, CAD models based on a genetic algorithm and differential evolution are first developed to synthesize a rectangular patch antenna with a microstrip feed line. Transmission line method (TLM) analysis is then used to develop the proposed CAD model for a microstrip patch antenna. In the proposed CAD models, the input parameters are the design/operating frequency, the thickness of the substrate used, and the permeability ($$\mu$$) of the substrate material, whereas the outputs are the dimensions of the structural design of the radiating patch and the microstrip feed line. The CST MWS EM tool is also used to design the antenna and validate the parameters of the synthesized antenna. A comparison between the two CAD models is presented. After the successful design of the CAD model for the microstrip antenna, the metamaterial synthesis technique is applied. Then, a metamaterial lens is designed with the help of the proposed CAD model and used to improve the performance of an antenna for use in TCAS applications. A comparison of the performance improvement is given in tabular form towards the end of the paper, including both the simulated and measured results.