On scattering from an array of absorptive material coated cones by the PWS approach

The electromagnetic scattering from periodical coated pyramids/cones array is important information in design and evaluation of a calibration source for the microwave radiometer system. In this paper, we implemented the plane-wave spectrum (PWS) composition method in finding the scattering of arbitrary concentrated beam from a finite-sized absorptive material coated array. In this method, the incident beam is decomposed into a set of plane-waves, then the total scattering from the periodical structure is constructed by re-composing the array scattering to each plane-wave, which can be obtained efficiently by general periodic modeling. Therefore a large-scale problem is turned into a set of small-scale ones. Further more, the results by periodic modeling are reusable in obtaining the total scattering of concentrated illuminating beams with various parameters. Meanwhile, we performed scattering modeling directly of the whole finite-sized calibration source structure to provide reference results. As demonstrated, the scattering results by the whole structure modeling and the PWS approach agree well with each other. The PWS composition method is proven to be simple in implementation and with good efficiency and accuracy, in finding the scattering of arbitrary concentrated beams from the finite-sized periodical microwave calibration source structure.