Design of a Subwavelength Patch Antenna Using Metamaterials

We present our design of a subwavelength patch antenna using metamaterials for its small size. Metamaterials are constructed of periodic resonant embedded circuits made up of 8 times 2 loop arrays with an inductance L terminated to a series capacitor C in the substrate to create an artificial magnetic molecule. The subwavelength elements in these structures make them behave as an effective medium with negative values of permittivity and permeability at the frequencies of interest. Their performance and physical parameters can be characterized using the analytical transmission line model. To simplify construction, our antenna was composed of six substrate layers for the periodic resonant embedded loop circuits, with inductance L terminated to a series capacitor C in the substrate. The radiation characteristics of a subwavelength patch antenna using metamaterials are calculated using CST Microwave Studio. The experimental results show that the wavelength of our subwavelength patch antenna using metamaterials with rectangular LC loop arrays is 1/18 that of the conventional patch antenna without LC loop arrays. The measured results are in good agreement with the calculated results.