Design of a MIMO Antenna with High Gain and Enhanced Isolation for WLAN Applications

A multi-input multi-output (MIMO) antenna for wireless local area network (WLAN) applications operating in 2.4 GHz and 5.8 GHz frequency bands is proposed in this paper. The proposed dual-band MIMO antenna is composed of two symmetrical radiation elements, and the isolation performance is improved by adopting parasitic elements and a defective ground plane. The measured reflection coefficients are less than -10 dB in the bandwidth range of 2.12-2.8 GHz and 4.95-6.65 GHz, respectively. The measurements show excellent isolation of -21 dB and -15 dB in both desired frequency bands, respectively. The total peak gain is greater than 4.8 dBi. The calculated envelope correlation coefficients (ECC), based on the measured S-parameters, are smaller than 0.01 and 0.024 in the lower and higher frequency bands, respectively. The dimension of the presented antenna occupies 50 x 40 x 1.59 mm(3). It is suitable for IEEE 802.11 a/b/g/n (2.4-2.4835 GHz, 5.15-5.35 GHz and 5.725-5.85 GHz) WLAN applications.