Variable permittivity dielectric material loaded stepped-horn antenna

20aperture region and 11Ps is the magnetic field in the half-space. The expression for themagnetic field in the half space Hhst is constructed by means of the electric vector potentialand magnetic scalar potential ensuring that Maxwell's equations and the radiation conditionare satisfied. Since magnetic field is linearly dependent on the magnetic current density,it can be written as fits (—M) = (la). fit" is the superposition of that due toimpressed field due to modal fields in the waveguide region radiating in the presence of theclosed aperture, 11:7", and that due to the equivalent current, denoted as Hwgt (M)If (2.36) is rewritten using (2.37)To apply the method of moments, the unknown magnetic current density M is expanded interms of a set of linearly independent basis functions, Mnwhere 1/n, are unknown expansion coefficients. Here, NM is the number of unknowncoefficients 142, to be determined by using the subdomain basis function. Substituting (2.39)into (2.38) leads toEnforcement of the continuity equation of magnetic fields by linearly independent testingfunctions Wm leads to the set of linear equations system. Solution of this system of linearequations determines the set of unknown coefficients Vn, leading to determination of M.Linear equations system obtained from (2.40) can be written in a matrix form as