Compact Stacked Impedance-Sheet Resonator Antenna using Characteristic Mode Analysis for 5G and 6G Networks

Ultra-massive multiple-in-multiple-out (UM-MIMO) antenna has been listed as one of the key technologies in recently released 6G white papers, which requires a massive number of compact antenna of high performance to coexist in a limited aperture. Metasurface antenna of controllable modes is a promising candidate but suffers from aperture size greater than half a wavelength. To address this challenge, the concept of stacked impedance-sheet resonator antenna is proposed for size reduction of metasurface antennas. Characteristic mode analysis is used for feeding guidance and insightful understanding of the proposed antenna, which is prototyped at the 3.5-GHz bands.