Compact broadband slot MIMO antenna with a stub-loaded radiator

A novel approach to enhance bandwidth of slot MIMO antenna is proposed. It is found that loading a stub in a dipole or slot antenna can control high-order resonant modes of the antenna to realize a multimode radiator as a multimode resonator in filters, which can effectively enhance the bandwidth of the antenna. As an example, a slot antenna with a stub-loaded dual-mode radiator is described. An explanation on its operating principle is given. In order to prove the approach is applicable, a slot MIMO antenna with a stub-loaded dual-mode radiator is designed for mobile handsets. Finally, the approach is extended to a slot MIMO antenna with a loaded-multi-slot-stub multimode radiator. Both of the two MIMO antennas are fabricated and measured to verify the predicted performance.