Radio Science

The backscattered field of a thin wire loop for E polarization

Authors

  • Joseph W. Burns,

  • Thomas B. A. Senior


Abstract

For a thin wire loop illuminated by a plane electromagnetic wave, the backscattered field is determined when the incident electric vector is parallel to the plane of the loop. The complete second order GTD solution is obtained and found to be in excellent agreement with numerical data at angles close to normal incidence on the loop. At wide angles, however, a substantial disagreement exists, and an analysis of the data shows that the discrepancy is due to current waves circulating around the loop. The waves are similar to those previously found for H polarization, and using a simple model for the circulating current, the corresponding contribution to the backscattered field is determined. When this is added to the GTD solution, the resulting expression for the backscattered field is in good agreement with the numerical data for all angles of incidence and all loop diameters greater than a wavelength.