Near Field Synthesis Based on Multi-Port Antenna Radiation Matrix Eigenfields

The attainable performances of a general formulation employing radiation matrix eigenfields of multi-port antennas to synthesize near-field distributions are investigated. Field synthesis performed on open or closed surfaces, proximate to or enclosing an antenna array, either based on both electric and magnetic target field distributions or just the former, are presented to illustrate the key features of the synthesis technique and its sensitivity with respect to realistic random magnitude and phase variations of the array excitation profiles. Guidelines to perform synthesis and the steering of the complex near-field distributions are then suggested. The propagation characteristics of diffraction-resistant Bessel, OAM Bessel, and Airy beams in their actual finite-energy implementation, when they are excited by finite-size antenna arrays are finally investigated.