Aperture field reconstruction by calculated cylindrical near field

Cylindrical Near-Field Measurements

A full characterization of the far-field noise obtained from cylindrical nearto far-field transformation, for a white Gaussian, space stationary, near-field noise is derived. A possible source for such noise is the receiver additive noise. The noise characterization is done by obtaining the autocorrelation of the far-field noise, which is shown to be easily computed during the transformation pr...

Field of view for near-field aperture synthesis imaging.

Aperture synthesis techniques are increasingly being employed to provide high angular resolution images in situations where the object of interest is in the near field of the interferometric array. Previous work has showed that an aperture synthesis array can be refocused on an object in the near field of an array, provided that the object is smaller than the effective Fresnel zone size corresp...

Cylindrical/Spherical Near-Field Antenna Measurement System

A low-cost, fully operational cylindrical and spherical near-field antenna measurement system designed, built, and programmed by a University of Rhode Island Capstone team is presented. The goal of this project was to modify an existing planar near-field system and apply new processing techniques to extract the far-field patterns of an antenna under test (AUT) of any physical shape. The aim of ...

Evaluation of 2D concentrically braced frames with cylindrical dampers subjected to near-field earthquake ground motions

Near field earthquakes have imposed major damage to buildings in the past years. In some cases, the intensity of such damage is too considerable to be disregarded. The most effective way to improve seismic performance of buildings is applying a seismic control technique. The cylindrical friction damper is one of these methods, which has become popular for its desirable performance in the energy...

Truncation-error Reduction in 2d Cylindrical/spherical Near-field Measurements