Compact Broadband MIMO Antenna With Parasitic Strip

A broadband printed directive antenna with parasitic strip and compact size is presented, which is designed as an antenna element for a multiple-input-multiple-output (MIMO) system. The antenna is composed of a meander dipole, a concave parabolic reflector, and a parasitic strip that is utilized to obtain good impedance matching. The parabolic reflector is utilized to minimize antenna dimensions as well as to enhance the directivity in lower band. Moreover, a rectangular metal strip worked as a director is used to broaden the impedance bandwidth and improve the gain at upper band. Four antenna elements are placed orthogonal to each other for miniaturized size and good isolation. Experimental results indicate the proposed MIMO array achieves a broad impedance bandwidth of 23.9% (0.63 GHz, 2.32-2.95 GHz) while having a compact size of 0.68 lambda(0) x 0.68 lambda(0). Due to the compact size, low profile, and broad bandwidth, the proposed MIMO array is suitable for various MIMO communication systems.