Scattering from coated structures and antenna pattern control using impedance surfaces, part A/B

Balanis, Constantine A.; Polka, Lesley A.; Liu, Kefeng

The scattering from coated, conducting structures, specifically the coated dihedral corner reflector configuration and the coated strip/plate configuration is examined. The formulation uses impedance-wedge Uniform Theory of Diffraction scattering coefficients to calculate the diffracted fields. A finite-thickness coating is approximated using the impedance boundary condition to arrive at an equivalent impedance for the coating. The formulation of the impedance wedge coefficients is outlined. Far-field, perfectly conducting approximations are discussed. Problems with the present dihedral corner reflector model for certain angles of incidence and observation are discussed along with a potentially rectifying modification. Also, the capacity to measure the electromagnetic properties of lossy materials was developed. The effects of using multiple material coatings on the radiation pattern of the horn antenna were studied. Numerous computations were devoted toward the inverse problem of synthesizing desired radiation patterns using the impedance surfaces. Stabilizing the equivalent sheet impedance using the linear control condition was attempted, and it was found to be a very difficult task.

Document ID

19900016917

Acquisition Source

Legacy CDMS

Document Type

Contractor Report (CR)

Authors

Date Acquired

September 6, 2013

Publication Date

January 1, 1990

Subject Category

Report/Patent Number

Accession Number

90N26233

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Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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