Implementing Complementary Split Ring Resonators for Mutual Coupling Suppression in Dual Differentially-Fed Microstrip Patch Array Antenna

A coupled complementary split ring resonator (CSRR) for mutual coupling suppression in dual differentially fed microstrip patch antenna is presented in this paper. The antenna is a 1 ×2 array of microstrip patches with a pair of CSRR placed on the ground plane to reduce the coupling between the two patches. By properly designing and adjusting coupling coefficient between the pair of CSRR, the coupled resonator can effectively suppress mutual coupling. The isolation is improved by employing a grounded single split ring resonator (SRR) that provides an alternative coupling path for space radiations. The approach significantly improves the isolation between the patches by over 10 dB and 5 dB in the E and H-planes respectively. An impedance bandwidth of 9.34-9.45 GHz with mutual coupling below -30 dB is also attained.