MIMO antenna with isolation enhancement for wireless USB dongle application at WLAN band

A compact MIMO antenna with isolation enhancement for WLAN band (2.4 - 2.497 GHz) is proposed. The proposed MIMO antenna consists of two identical folded monopole antennas each of which has the dimension of 5.1 mm × 10 mm. The separation between the two antennas is 4.8 mm (about 3.8% of the wavelength at 2.4 GHz). In order to realize the good isolation performance for such a small separation, a suspended strip is used to connect the two monopoles together and it forms an effective filter with the ground plane at the required frequency band. The proposed MIMO antenna system has the isolation of 10 dB on average and the maximum isolation of about 30 dB. The measured ECC values around the center frequency are less than 0.1.