A circularly polarised multiple input multiple output antenna with single-sense for sub-6 GHz 5G applications

In this study, a compact wideband circularly polarised Multiple Input Multiple Output (MIMO) antenna with the two parasitic elements is proposed. The printed monopole antenna for wideband circular polarisation proposed in authors' previous study is used as an antenna element. One-sided substrate reflector is installed at the back side of the antenna, positioned 0.2 lambda 0 away, to improve the gain. The circularly polarised radiation, deteriorated by the influence of mutual coupling of two antenna elements and reflector, is improved by deploying two parasitic elements on the bottom layer of the antenna's substrate. The antenna's size is 0.99 lambda 0 x 0.32 lambda 0 and the reflector's size is 1.41 lambda 0 x 0.82 lambda 0 (lambda 0 is the free-space wavelength at lowest operating frequency). The measured bandwidth of 10 dB impedance with a 3 dB axial ratio is 33.49% from 3.53 to 4.95 GHz, which can be utilised for sub-6 GHz 5G applications. The simulated and experimental results are compared to validate the antenna characteristics. A compact wideband circularly polarised MIMO antenna with the two parasitic elements is proposed. One-sided substrate reflector is installed at the back side of the antenna to improve the antenna gain in the boresight direction. The measured bandwidth of 10 dB impedance with a 3 dB axial ratio is 33.49% from 3.53 to 4.95 GHz, which can be utilised for sub-6 GHz 5G applications.image

Automated summary

A compact wideband circularly polarised MIMO antenna with two parasitic elements is proposed in this study. The antenna's gain is improved by installing a one-sided substrate reflector at the back side, and the circularly polarised radiation is enhanced by deploying two parasitic elements. The measured impedance bandwidth with a 3 dB axial ratio is 33.49% from 3.53 to 4.95 GHz, suitable for sub-6 GHz 5G applications. The simulated and experimental results validate the antenna characteristics.