A Multiband MIMO Antenna for Future Generation Handset Applications

A very simple multiband multiple-input multiple-output (MIMO) antenna system is developed. The proposed antenna system consists of two alphabetic letter shaped elements: one is C-shaped and another is inverted L-shaped - all together can combinedly operate the wideband frequency range of LTE-1, 2, 3, 7, 12, 13, 14, 22, 40, 43 and WLAN bands. The C-shaped antenna element excites lower order resonance to cover lower frequency bands from 700 MHz to 800 MHz, whereas L-shaped is responsible for other higher frequency bands (1.7-3.8 GHz). The reflection coefficient is achieved 6 dB in case of LTE-2, LTE-3, LTE-12, LTE-13, LTE-14 bands, but for all other bands it is greater than 10 dB. The two U-shaped and I-shaped slots are introduced to reduce the coupling effects between two antenna unit. The isolation of this proposed MIMO antenna is achieved higher than 15 dB with a compact size of 70x70x0.8mm(3) which is suitable for 4G/LTE ultra slim mobile phones and wireless devices.