Anisotropic metamaterials as antenna substrate to enhance directivity

Simulations have been carried out on metamaterials in the microwave regime. S‐parameters obtained from waveguide simulations of a unit cell are used to retrieve the effective permittivity and permeability with which we compute the far‐field radiation of a monopole embedded in a metamaterial substrate using an analytic method. We find that the analytic method is able to predict features of the experimental results, implying that within a certain frequency range, we can treat the metamaterial as being anisotropically homogeneous. Based on the methodology, a structure is optimized for the application of metamaterials as antenna substrate to enhance directivity by minimizing its refractive index. The experimental results are presented and compared with the analytic calculations. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 680–683, 2006; Pubished online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.21441