Compact Eight-Port QMSIW Cavity-Backed MIMO Antenna
Gunjan Srivastava, Akhilesh Mohan
Abstract
An 8-port modified-shielded quarter mode substrate integrated waveguide (MS-QMSIW) multiple-input-multiple–output (MIMO) antenna for WLAN applications is presented in this letter. The MIMO antenna comprises four MS-QMSIW resonators that are placed adjacent to each other, sharing the via side walls. Each MS-QMSIW resonator is inset fed orthogonally through a pair of microstrip feed lines. It utilizes the TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">110</sub> mode of the QMSIW resonator for the radiations at 5.5 GHz. The designed MIMO antenna can be easily re-designed in a 4.6 GHz to 6.4 GHz frequency band by varying one of the design parameters without changing the overall size. The isolation between the antenna elements is better than 22 dB over the entire operating band. The antenna exhibits a gain of 5.75 dBi and a radiation efficiency of better than 85%.