A novel and compact reconfigurable quad-port orthogonal Multi-Input-Multi-Output (MIMO) antenna is proposed for Dedicated Short Range Communication (DSRC), WLAN, RADAR and Ku-band applications. The proposed MIMO antenna is fabricated on FR-4 substrate of dimensions 40 × 40 × 0.8 mm³. Each element of MIMO antenna has attained different Ku-band frequencies and lower frequency operating band 5.5–9.2 GHz suitable for DSRC, WLAN and RADAR applications is obtained by M-3 element of proposed MIMO antenna for diode ON condition in ground plane. Individual MIMO element is investigated with respect to S-parameters, isolation, current distribution, radiation pattern, gain, radiation efficiency, Total Active Reflection Coefficient (TARC) and diversity performance parameters like Envelope Correlation Coefficient (ECC), Diversity Gain (DG) and Mean Effective Gain (MEG). Overall gain of MIMO antenna ranges between 3.36 and 7.57 dB in operating bands and radiation efficiency ranges between 70.4 and 89.7%. Time domain characteristics are analyzed using group delay with respect to all ports and group delay is less than 1.5 ns. ECC values are below 0.05, DG is very close to 10 and MEG_i < −3 dB. The proposed quad-port MIMO antenna exhibits good diversity performance and is validated by comparing computer generated and experimental results.

提出了一种新颖，紧凑的可重构四端口正交多输入多输出（MIMO）天线，用于专用短程通信（DSRC），WLAN，RADAR和Ku频段应用。拟议的MIMO天线是在尺寸为40×40×0.8 mm ^3的FR-4基板上制造的。MIMO天线的M-3元件可在接地平面上实现二极管导通的条件下获得，因此MIMO天线的每个元件均具有不同的Ku频段频率，并且适用于DSRC，WLAN和RADAR应用的5.5-9.2 GHz的较低频率工作频带。研究了各个MIMO元素的S参数，隔离度，电流分布，辐射方向图，增益，辐射效率，总有源反射系数（TARC）和分集性能参数，例如包络相关系数（ECC），分集增益（DG）和平均有效增益（MEG）。在工作频带中，MIMO天线的整体增益范围在3.36至7.57 dB之间，辐射效率范围在70.4至89.7％之间。使用相对于所有端口的群时延分析时域特性，群时延小于1.5 ns。_i  <-3分贝。所提出的四端口MIMO天线具有良好的分集性能，并且通过比较计算机生成的结果和实验结果进行了验证。