Wideband Coplanar Waveguide MIMO Antenna for 6G Millimeter-Wave Applications with Defected Ground Structure

This research study introduces a novel small antenna with wideband capacity for the higher frequency range. As a possible contender for 6G wireless networks, the proposed antenna is designed to target the 6G Millimeter-Wave (mmWave) operating bands spanning 25 GHz to 33.5 GHz. With a microstrip patch structure fed by a coplanar waveguide (CPW) with the defected ground structure (DGS), a single antenna is introduced and then a design of 2 x 2 MIMO antenna is presented. The single antenna has 2 elements, while the 2 x 2 MIMO antenna has 8 elements. It achieves remarkably well in terms of return loss of 8.5 GHz wideband, which is anticipated to be used for several applications in 6G mmWave technology.

Dynamic IRS Allocation for Spectrum-Sharing MIMO Communication and Radar Systems

This paper investigates the use of intelligent reflecting surfaces (IRS) to assist cellular communications and radar sensing operations in a communications and sensing setup. The IRS dynamically allocates reflecting elements to simultaneously localize a target and assist a user's communication. To achieve this, we propose a novel optimization framework that jointly addresses beamforming design and IRS element allocation. Specifically, we formulate a Weighted Minimum Mean Square Error (WMMSE)-based approach that iteratively optimizes the transmit and receive beamforming vectors, IRS phase shifts, and element allocation. The allocation mechanism adaptively balances the number of IRS elements dedicated to communication and sensing subsystems by leveraging the signal-to-noise-plus-interference-ratio (SINR) between the two. The proposed solution ensures efficient resource utilization while maintaining performance trade-offs. Numerical results demonstrate significant improvements in both communication and sensing SINRs under varying system parameters.