Isolation-improved LTE MIMO antenna for laptop-computer applications

A simple technique for achieving enhanced isolation between two long-term evolution (LTE) antennas operating at the LTE700/2300/2500 band for the multiple-input multiple-output (MIMO) operation in the laptop computer is presented. The two antennas are mounted along the top edge of the supporting metal plate, which is generally disposed on the inner surface of the upper cover of the laptop computer. Improved isolation (simulated S₂₁ better than -17 dB in the LTE700 band and -30 dB in the LTE2300/2500 bands) between the two antennas is easily achieved. By arranging a pair of the isolation elements at two separate null current locations of the excited surface current distribution of the LTE700-band modes of the two antennas can improve isolation in the LTE700 band. It can effectively cause weaker surface currents flowing along the top edge of the supporting metal plate. Over the lower and upper bands, the antenna efficiencies are about 46-58% and 50-68%, respectively.