A system for unobtrusive measurement of surface currents

A backpropagation technique is investigated that uses the plane wave spectrum to reconstruct the subwavelength features of the current distribution on flat surfaces without damaging the surface under measurement. The technique employs spectral and spatial filtering of the measured signal to capture...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on antennas and propagation 2001-02, Vol.49 (2), p.174-184
Main Authors: Harms, P.H., Maloney, J.G., Kesler, M.P., Kuster, E.J., Smith, G.S.
Format: Article
Language:English
Subjects:
Antenna measurements
Antennas and propagation
Back propagation
Backpropagation
Current distribution
Current measurement
Horn antennas
Magnetic field measurement
Probes
Studies
Surface reconstruction
Surface waves
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A backpropagation technique is investigated that uses the plane wave spectrum to reconstruct the subwavelength features of the current distribution on flat surfaces without damaging the surface under measurement. The technique employs spectral and spatial filtering of the measured signal to capture the propagating spectrum as well as a portion of the evanescent spectrum. Special consideration is given to avoiding exponential amplification of measurement noise during backpropagation of the evanescent spectrum. This approach uses equipment commonly available in antenna measurement laboratories, for example, a network analyzer, a horn antenna, a magnetic field probe, and an automated positioning apparatus for the probe. The approach is first studied using computer simulations. The results from the simulations are then used as a guide to develop an actual measurement system. The measurement system is constructed and tested by measuring the surface current on a slotted plate. The measured current distributions are compared with results from finite-difference time-domain (FDTD) computations to demonstrate the feasibility of the technique.
ISSN:0018-926X
1558-2221
DOI:10.1109/8.914266