Study on the Effect of the Wall in the Performance of an Intelligent Reflective Surface for Providing Coverage in mm-Wave Frequencies

This work presents the design of a passive reflectarray-based Intelligent Reflective Surface (IRS) to improve the coverage in a 5G scenario at 28 GHz. The IRS generates a wide beam in azimuth with a narrow beam in elevation, using a Phase-Only Synthesis with the Intersection Approach to design it. The resulting phase-shift distribution radiates a field pattern that covers an angular range of 12.75° and 2° in azimuth and elevation. Due to the IRS is placed on a building face, the surrender wall effect is analyzed. Different building materials are electromagnetically characterized in the Ka-band. Then, the effect of the wall is included in the radiated field. The results clearly demonstrate that the wall produces a strong reflection on the specular direction, deeply affecting the coverage. These preliminary results show the importance of including the wall in the design process.