Electromagnetic metamaterial insulator to eliminate substrate surface waves

Metamaterial EM insulators are designed to eliminate mutual coupling between closely packed array elements. This technique allows for array element design in isolation, without consideration of mutual coupling effects. Eliminating mutual coupling also allows for denser packing and higher directivity in antenna arrays. By placing isolation walls along the radiating edges of a patch on a /spl lambda//sub 0//3/spl times//spl lambda//sub 0//3 ground plane a 19.2dB front-to-back ratio is achieved. Metamaterial isolation walls 0.05/spl lambda//sub 0/ thick exhibit -10 dB isolation bandwidths of 2-6% with very low losses for various geometries and greater than 20 dB peak isolation is achieved for array element spacing of 0.2/spl lambda//sub 0/.