Near-Field Model for the Computation of Coverage Generated by an IRS: Formulation and Validation

In this work a model to compute the near-field of an Intelligent Reflective Surface is presented. The proposed approach computes the near-field by means of the Huygens' Principle and the Principle of Superposition using the formulation of classical antenna apertures. The model is fully described and numerically simulated by designing a reflectarray at mmWave frequency and radiating in the Fresnel zone, similar to an IRS in an indoor scenario for 5G FR2 communications. The design is manufactured to experimentally validate the proposed model. The measurements agree with simulations for the copolar and cross-polar components of the radiated near-field. This approach presents a simply model to compute the near-field which provides a good prediction of the radiated near-field.