Performance enhanced folded multiband MIMO antenna for mobile terminals

A novel compact folded antenna for 4G and 5G application in handheld devices such as mobile phones is proposed in this paper. The radiator comprises of meandered monopole, dual L-Shaped monopole, square radiator, asymmetric U-Shaped monopole, Closed Loop resonator, F-Shaped stub for providing the desired operating bands. The size reduction is achieved using folding technique. The antenna can be easily folded and integrated at the top right corner within the metal casing of the devices. Folded structure with the foot print of 50 x 6 mm(2) covers multiband operation such as LTE700 / GSM850 / 900 / LTE 2300 / WLAN 2400 / LTE 2500 / Wi-MAX 3500 / Wi-Fi 5200/5800 MHz corresponds to 2G/3G/4G/5G services. To provide high data rate and throughput, MIMO concept is exploited with the folded radiators at the top left and right corners of the printed circuit board. The realized gain and radiation efficiency of the proposed antenna are 2.45/4.12/4.54/5.03/6.58 dBi and 82/85/87/89/90% respectively at the design frequencies 0.7/2.3/2.5/3.5/5.8 GHz. The SAR values of the folded antenna is computed and found to be less than 1.6 W/Kg.