SICL-Based Multifunctional MIMO Antenna Array for 5G and Beyond (B5G) Applications
Naman Baghel, Soumava Mukherjee
Abstract
This research study introduces a Multiple-Input Multiple-Output (MIMO) antenna array for simultaneous operation in 5G FR2 millimeter wave and 6G mid-band frequencies. At 10 GHz, a Substrate Integrated Waveguide (SIW) cavity backed slot antenna (CBSA) is designed to radiate in broadside direction with a gain of 6.3 dBi. A rhombus-shaped slot is engraved on the top layer of the cavity and its position is tuned to obtain a bandwidth of 750 MHz to satisfy the forthcoming 6G mid-band. At 28 GHz, a Substrate Integrated Coaxial Line (SICL) fed novel ±45◦ inclined crossed dipole antenna exhibiting a gain of 6 dBi is designed. An impedance matching network is designed in the middle layer to achieve a bandwidth of 3.5 GHz, enabling support for the entire n261 and n257 bands of the FR2 millimeter wave frequency. In order to have simultaneous operation at 10 GHz and 28 GHz, a novel SICL transmission line based feed section is proposed. In the lower band (10 GHz), one arm of the feed section feeding the crossed dipole behaves as an open-circuited line, facilitating wave propagation exclusively in the lower band CBSA. Similar effect is obtained in the other arm for operation in the upper band (28 GHz). This technique helps in attaining simultaneous 5G/6G performance while having negligible effect at the other operating frequency.