Near-Field to Far-Field Transformation Techniques with Spiral Scannings: A Comprehensive Review

The Unified Theory of Near-field–far-field Transformations with Spiral Scannings for Nonspherical Antennas

The unified theory of near-field–far-field transformations with spiral scannings for quasi-spherical antennas is extended in this paper to the case of nonspherical ones, i.e., antennas with two dimensions very different from the third one. To this end, these antennas are no longer considered as enclosed in a sphere, but in a proper convex domain bounded by a rotational surface. The extension, h...

A Nonredundant Near-Field to Far-Field Transformation with Spherical Spiral Scanning for Nonspherical Antennas

A fast and accurate near-field – far-field transformation technique with spherical spiral scanning tailored for nonspherical antennas, i.e., radiating systems with two dimensions very different from the third one, is developed in this paper. To this end, an antenna with one or two predominant dimensions (e.g., base station antennas and reflectarrays) is no longer considered as enclosed in a sph...

An Alternative Spherical near Field to Far Field Transformation

Near-field imaging with far-field data

Using the inverse diffractive grating problem as an example, we demonstrate how a super-resolution can be achieved stably by using far-field data. The idea is to place a slab of a homogeneous medium with a large index of refraction above the grating surface, and more propagating wave modes can be utilized from the far-field data which contributes to the reconstruction resolution. © 2016 Elsevie...

Polarization-Current-Based FDTD Near-to-Far-Field Transformation

A new near-to-far-field transformation algorithm for three-dimensional finite-different time-domain is presented in this article. This new approach is based directly on the polarization current of the scatterer, not the scattered near fields. It therefore eliminates the numerical errors originating from the spatial offset of the E and H fields, inherent in the standard near-to-far-field transfo...