Dual-Band Compact Six-Element Millimeter Wave MIMO Antenna: Design, Characterization, and Its Application for V2V Communication

This article presents a compact six-element multiple-input multiple-output (MIMO) antenna for vehicle-to-vehicle (V2V) communications. The proposed structure is planar, having a dimension of $1.28\lambda _{0} \boldsymbol {\times } 2.04\lambda _{0}$ , where $\lambda _{0}$ is the wavelength at 25.5 GHz, resonating in n258 and n260 bands. The antenna is a modified rectangular patch designed to generate TM10 and TM02 modes, resulting in vertical and horizontal polarization at 25.5 GHz and 38 GHz. The measured bandwidth of the MIMO antenna is 800 MHz at the n258 band, i.e., 25.1-25.9 GHz, and 850 MHz at the n260 band, i.e., 37.75-38.6 GHz. The isolation between the elements is improved by incorporating a novel open-ended decoupling structure. It resulted in an isolation that surpass 20 dB at both bands. The antenna has a broadside radiation pattern with a maximum realized gain of 9 dBi and 7.2 dBi at 25.5 and 38 GHz, respectively. The antenna is validated for various diversity parameters such as envelope correlation coefficient, diversity gain, channel capacity loss, and mean effective gain. Also, the performance of the proposed antenna for V2V communication is analyzed for line-of-sight and non-line-of-sight conditions. The estimated channel capacity, path loss, and link budget for the above-said condition suggest that the antenna is suitable for V2V communications.