The paper focuses on computational electromagnetics. To reduce the computation burden, the domain is divided into smaller subdomains that are solved separately. A feature of such a scheme is the expression of the multipole expansion in one subdomain due to the sources placed in another subdomain. This work analyzes an alternative method to do this task. Now, the subdomains enclosing the antennas can have an arbitrary shape, hence reducing the distances between the antennas and the scatterers.

A new analytical method has been introduced to exactly solve the classical problem of electromagnetic diffraction by a slit. It is faster and easier to implement than the standard solution using Mathieu functions. Moreover, the paper contains a successful comparison of the scattered fields for an incident plane wave with that one obtained for an incident Gaussian beam which is easily modelled by a complex-source beam.

In this paper we explain a novel method to increase the bandwidth of a top-loaded monopole antenna by using a shield made of dispersive magnetic material. We apply the Kramers-Kronig transforms to derive physically correct real and imaginary parts of the dispersive magnetic material. We aim at a compensation of the electric by a magnetic stored energy for a wide frequency range. Independent numerical solutions using the commercial field solver CST support the results of our investiagation.