Exact solutions in microwave holography validated by measurements

We present exact solutions to problems of antenna holography based on planar, cylindrical, and spherical near-field data as processed by our novel Field Mapping Algorithm (FMA). On the basis of the FMA, full field distribution information in the source region is determined exactly, from two tangential field components over a planar, cylindrical, or spherical surface. Stated in so many words, all three components of both electric and magnetic fields in the antenna aperture are obtained exactly from two-component near-field data. Exact solutions for microwave holography were found in this way utilizing planar, cylindrical, and spherical near-field data. These closed-form solutions have been verified by analytic examples and various cases simulated numerically on the computer. In addition, eight hardware measurements were carried out to validate the closed-form FMA solutions, as follows: in planar holography, Case 1, a slot array antenna, with and without aperture blockage, Case 2, a patch antenna with adjacent blockage, Case 3, a horn antenna with model aircraft as a source of interference in its vicinity, Case 4, field transit across a dielectric lens, Case 5, metallic obstacle detection within a multilayered dielectric medium, and Case 6, having an omni antenna under test and planar near-field data acquired over all six faces of an enclosing rectangular box; in cylindrical holography, Case 7, with measured near field from a sector antenna; and finally, in spherical holography, Case 8, the measured near field being that of a patch antenna. Excellent results were obtained throughout, with antenna geometries and/or field distributions clearly revealed across all eight source regions.