A Compact Frequency-Reconfigurable Multiband LTE MIMO Antenna for Laptop Applications

A compact frequency-reconfigurable multipleinput-multiple-output (MIMO) antenna on a laptop is proposed for multiband LTE services. Each MIMO antenna consists of two planar inverted-F antenna (PIFA) elements, using a T-shaped dc line and two p-i-n diodes (D1 and D2), in conjunction with the proximity-coupled feed structure. By effectively minimizing its dimension and its interference with antenna performance, the proposed T-shaped dc line is designed to fit within the proximity-coupled feed structure. The proposed MIMO antenna covers the LTE 17/13 bands (704-787 MHz, VSWR <; 3) at State 1 (D1 and D2: ON state), and the LTE 20/7 bands (791-862 MHz, 2500-2690 MHz, VSWR <; 3) at State 2 (D1 and D2: OFF state). The proposed antenna obtains high isolation (> 20 dB), low envelope correlation coefficient (ECC <; 0.0161), and total efficiency of greater than 51%, for all operating frequency bands.