Frequency Reconfigurable Antenna Array with Compact End-Fire Radiators for 4G/5G Mobile Handsets

Recently, the need of frequency reconfigurable antenna has been widely increased in the field of mobile communications due to its attractive features. A new design of reconfigurable MIMO antenna for smartphone applications is introduced in this paper. The structure of the design consists of four reconfigurable C-shaped slot radiators with miniaturized sizes etched on the corners of the mobile handsets. The reconfigurability characteristic is obtained by controlling the ON/OFF states of the integrated PIN diodes into the slot elements. The operation frequency of the antenna can work at two frequencies: 2.6 and 3.5 GHz for supporting 4G and 5G mobile terminals. A good impedance bandwidth (S ₁₁ ≤ -10 dB) of 400 MHz and 1 GHz have been obtained in ON and OFF states of the diodes, respectively. For S ₁₁ ≤ -6 dB, these values are from 2.4-2.95 GHz and 3-4.5 GHz. The efficiency characteristic of the MIMO antenna in the presence of human-hand has been studied.