Compact Wideband Decoupling and Matching Network Design for Dual-Antenna Array

A novel wideband decoupling technique for multiple-input–multiple-output (MIMO) antenna arrays is proposed. Broadband isolation is achieved by creating controllable transmission zeros ( S 21 = 0) at two separated frequencies. The newly developed decoupling network is compact in size due to the elimination of multiple transmission line elements and the external matching circuit. Simulation and measurement results show that the proposed method can offer substantial enhancement in port isolation, pattern diversity (envelope correlation coefficient), and radiation efficiency over the designated frequency range.