Ultra-Near Field Facility for RCS Research
Abstract
This investigation demonstrated, experimentally and theoretically, the application of near field and ultra-near field techniques in the microwave region to characterize the scattering and radiation phenomena near targets and in the reactive region of antenna. The Ultra-Near Field Facility research facility was designed and built at NRL for this purpose. Requisite sensors and associated processing software for measuring the ultra-near fields from bistatically illuminated targets as well as antenna systems were developed and tested. The present phase of the program focused principally on the investigation of the ultra-near field scattering from planar structures. Important features of EM phenomena associated with ship stacks/masts can be analyzed by studying the scattering from classes of planar structures. This motivated the present approach. To gain deeper insight into the scattering mechanisms and to characterize the fields in the proximity of such surfaces, extensive computer simulations were also carried out. In the modeling, it was assumed that the surfaces were two dimensional (2-D) permitting the effect of vertical and horizontal polarization to be studied independently. The numerical simulations were based on a method of moments formulation for bodies of translation (BOTs). These constitute a general class of 2-D surfaces. They are extensively treated in the literature and thus provide a robust departure point for this effort. The propagated and evanescent fields in the proximity of these surfaces were delineated using frequency wave-vector (Omega-Kappa) transformations of the calculated and measured fields. The effect of surface discontinuities on the propagating and evanescent field structure was examined. Preliminary investigations were also carried out for selected finite quasi-periodic arrays and models provided by NSWCCD.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 31, 2001
- Accession Number
- ADA394988
Entities
People
- David L. Smith
- L. N. Medgyesi-mitschang
- P. G. Moore
- Samuel G. Lambrakos
Organizations
- United States Naval Research Laboratory