MIMO antennas for mobile handsets

In this paper, two multiband MIMO antennas for mobile handsets are proposed. The first antenna is capable of covering GSM900, GSM1800, GSM1900, and UMTS. It has two loop type antenna elements, which are with the same structures and dimensions. The dimensions of the antenna element is 22.5*25mm². Two structures which are slot and inverted-L branches on the ground, are used to minimize the mature coupling between the two antenna elements. The second antenna can cover GSM1800, GSM1900, UMTS, WLAN and LTE frequency bands. The presented antenna consist of two coupled fed monopole antennas that are oriented diagonally at the non-grounded portion of the circuit board. Two decoupling structures are etched diagonally on the bottom layer of the circuit board to improve the isolation between the two antenna elements. Both of simulation and measurement results are shown to illustrate the performance of the proposed two MIMO antennas.