IET MICROWAVES ANTENNAS & PROPAGATION, cilt.11, sa.5, ss.718-725, 2017 (SCI-Expanded)
Low-profile band-notched G-shaped ultra-wideband (UWB) multiple input multiple output (MIMO) antenna design for mobile terminals has been presented. In this context, two UWB MIMO antenna systems have been designed: The first is with square elements and the second is with G-shaped elements. An MIMO antenna with two symmetrical square elements each of 8x8mm(2) operating between 2.2 and 13.3GHz was firstly designed for the UWB applications. Each square element was fed through a 50- microstrip transmission line (MTL). A thin strip line was designed at the end of MTL to provide impedance matching. Although the isolation level between the elements was satisfactory for efficient MIMO implementation, a T-shaped strip on the ground was employed to further improve the isolation for low frequency. The frequency range of 4.4-6.2GHz which is an important band of wireless local area network (WLAN) standard was then notched by forming a G-shaped structure on the square element. The performance of G-shaped antenna system was studied in terms of important antenna characteristics and MIMO parameters. The results demonstrate that the G-shaped MIMO antenna has nearly omnidirectional patterns, stable gain and good diversity performance besides having low-profile elements.