10. Compact Wideband Printed MIMO/Diversity Monopole Antenna for GSM/UMTS and LTE Applications

Over the last decade, significant research effort has been devoted to enhance the isolation between multiple-input-multiple-output (MIMO) antenna elements. This has led to offer several solutions, which in terms of band calcifications may be categories as follows: narrow band, broadband and dual/triple band. Services that have been covered by the narrow band solutions include Long Term Evolution (LTE) 700–800 MHz, UMTS and WLAN 2.4, 5.2 and 5.8 GHz. Thus, within this chapter, a low profile printed crescent-shaped monopole MIMO diversity antenna for use in smart mobile devices is proposed. The mutual coupling is significantly mitigated by simply printing an I-shaped conductor over the ground place which is symmetrically placed between the two antenna elements. The proposed MIMO antenna exhibits a wideband frequency range from 1.8 to 2.6 GHz, equivalent to bandwidth of 54.5%, while simultaneously achieving an isolation of −14 dB. Moreover, the proposed antenna demonstrates nearly omnidirectional patters, acceptable power gain, good envelope correlation and channel capacity loss.