Accession Number:

ADA230526

Title:

Electromagnetic Scattering from Impedance Strips and Impedance-Loaded Conducting Strips

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING

Personal Author(s):

• Heaton, Marck C.

Report Date:

1990-12-01

Pagination or Media Count:

129.0

Abstract:

This paper investigates the scattering from impedance strips and impedance-loaded conducting strips. The UTd diffraction coefficient for an edge in a conductor is heuristically modified for impedance edges and junctions. Essentially, this is done by scaling the UTD diffraction coefficients according to changes in the geometrical optics field. The new diffraction coefficients are then used to investigate the scattering from impedance strips and impedance- loaded conducting strips. Both uniform and tapered impedances are considered. Results are compared to moment method and physical optics predictions and to measured data. The scattering pattern of a uniform impedance strip was seen to behave as that for a conducting strip, but at a lower level. However, tapering the impedance was seen to significantly decrease the sidelobe levels relative to the main lobe. Also, applying an impedance load to a conducting strip reduced the sidelobe levels. This was most pronounced for loads of tapered impedance. the modified UTD approach accurately predicted the sidelobe levels and locations for the simple impedance strips, and worked fairly well for the impedance-loaded conducting strips. The predictions for all geometries were better near broadside incidence than near edge-on.

Descriptors:

• *POWER LEVELS
• OPTICS
• SCATTERING
• PREDICTIONS
• THEORY
• THESES
• ELECTROMAGNETIC SCATTERING
• DIFFRACTION
• COEFFICIENTS
• LOW LEVEL
• PATTERNS
• METHOD OF MOMENTS
• IMPEDANCE
• SIDELOBES

Subject Categories:

• Electricity and Magnetism
• Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE