Inverse Fourier transform has been used to derive the gradient-index profiles of inhomogeneous films having spectral requirements. Two examples are given, and the corresponding experimental designs are presented. Results show a good agreement with the theory and evidences the reliability of the technology used to produce inhomogeneous media.
An inversion method which reproduces the radial variation of dielectric constant in a dielectric target from its microwave scattering pattern is presented. Inversion criteria are developed showing what part of the target can be reconstructed. The technique is applied to experimentally measured scattering patterns.
I t is recognized that the most favorable distribution of radiant energy in a diffraction pattern is that which corresponds to the best concentration around the center 0. This hypothesis is expressed by an extremal condition on the factor of encircled energy E ( W), that is, the ratio of the energy inside a circle of radius W and centered on the diffraction pattern, to the total energy in the same.
The determinaliol~ of a state of steady wave propagation through a periodic seqnence of lenses with minimal beam poxver loss is based on a previously published study of encircled energy in the visible region. The amplitude fu~lction T(N) derived from an extremum of the factor of encircled energy E ( W ) for a hxed abscissa TY_= W,, = 5 can be replaced with sufficient accuracy by the varied function T(s) = J J l ( a s ) / a r ; the periodic sequence of lenses illuininated by a lield distribution T(x) is analogous to a loxv-loss beam wave guide.With regard to this theoretical a~~a l y s i s and practical application, the authors describe the characteristics of a beam wave guide for millimeter waves which maintains an opti~num compron~ise between diffraction lossesand line dimensions. This analysis is completed by experimental results from a rnicro~vave beam xvave guide operating a t the 1.25 cm wavelength.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.