A novel multi-
antenna design approach is proposed to obtain uncorrelated and energy efficient antennas. By manipulating the
chassis, more than one characteristic mode is enabled to resonate at frequency below 1 GHz. With proper excitations for different characteristic
modes, which are inherently orthogonal to each other, well performed multiple antennas with low mutual
coupling and correlation are achieved. Three examples of
chassis manipulation, a bezel structure and two T-shaped structures with
metal strips along the
chassis, are introduced. With efficient excitations of the fundamental
dipole mode and T-strip mode, two antennas with low correlations and high total antenna efficiencies are achieved, with both antennas covering one or more of the
low frequency LTE bands 5, 6, 8, 12, 13, 14, 17, 18, 19, and 20 in combination with one or more of
high frequency LTE bands 1, 2, 3, 4, 9, 10, 11, 15, 16, 21, 23, 24, and 25.