Evaluation of the Far Field Radiated of a Flat AUT from Near-Field Samples Acquired via Planar Wide - Mesh Scanning

This paper presents an effective, probe-compensated, near-field to far-field (NF-FF) transformation adopting the planar wide-mesh scan (PWMS), tailored to flat antennas. The proposed technique relies upon a non-redundant sampling representation of the electromagnetic field radiated by a flat antenna under test (AUT), developed by modeling it as a disk with a radius equal to half of its maximum size. Moreover, it exploits an optimal sampling interpolation expansion to recover the NF data on the classical plane-rectangular lattice. The developed NFFF transformation allows one to attain a considerable decrease of the required NF samples as compared to the one which employs the classical plane-rectangular scan. Moreover, it allows also a significant reduction with respect to those with PWMS employing the other models usable for quasi-planar AUTs, i.e., the double bowl and the oblate spheroid modelings. At last, the proposed technique results to be more convenient than those adopting the models for quasi-planar AUTs, since the parameters expressions in the non-redundant representation are much simpler. Numerical and laboratory results are shown to assess the feasibility of the developed technique.