Isolation enhancement between two slot antenna elements using complementary split-ring resonators

In this paper, a decoupling structure based on complementary split-ring resonators is proposed to mitiage the mutual coupling between two slot antenna elements. The slot antenna elements are placed side-by-side, that are operating at 5.2 GHz frequency band for WLAN applications. Unlike previous attempts of utilizing the mushroom-like electromagnetic bandgap structures, complementary split-ring resonant inclusions are placed between two slot antenna elements in order to mitigate mutual coupling effects due to space waves coupling. The deployed decoupling structure results in ease of fabrication, since only etching of resonant decoupling patterns is required, thus maintaining the antenna system low-profile without the need for extra embedded layer, as presented in earlier studies. In this work, numerical full-wave simulations are carried out in order to show the capabilities of the developed decoupling technique in mutual coupling reduction. Based on the numerical results, reduction in mutual coupling between the two slot antenna elements by more than 25 dB was achieved in comparison to the reference case without any decoupling structure between the two slot antennas.