Defected ground structure with two resonances for decoupling of dual-band MIMO antenna

A defected ground structure (DGS) with two resonances is proposed to reduce mutual coupling of planar multiple-input-multiple-output (MIMO) antenna. A dual-band MIMO antenna is used for study. The antenna consists of two planar-inverted F-antenna (PIFA) elements printed symmetrically for dual-band operation. The defected ground structure (DGS) is placed between the two PIFA elements to reduce mutual coupling. The antenna is studied and designed using computer simulation, and then fabricated for measurement using the Satimo Starlab system. Results show that the MIMO antenna has the measured bandwidths of 1.56–2.78 GHz (1.22 GHz or 56%) and 4.7–5.82 GHz (1.12 GHz or 21%) in the lower and higher frequency bands, respectively, with mutual coupling of less than −15 dB.