Multipole Analysis of Electromagnetic Scattering
Application ID: 31901
The multipole expansion is a powerful tool for analyzing electromagnetic waves scattered by small objects. In the expansion, the scattered field is represented as a superposition of the fields created by a finite set of point multipoles. Each point multipole is connected to a unique electric current mode in the object. This connection can be harnessed to design scatterers with prescribed electromagnetic responses.
In this model, the multipole expansion is implemented and applied to the problem of scattering by a spherical particle. The calculated complex-valued expansion coefficients are compared with the analytical solution of the problem. Excellent agreement is obtained. The model can straightforwardly be adapted for scatterers of arbitrary shape and composition. The implementation is also applicable to periodic arrays of scatterers.
The model uses the Electromagnetic Waves, Frequency Domain physics interface of the Wave Optics module. With minor modifications, it can be set to use the equivalent physics interface of the RF module.
This model example illustrates applications of this type that would nominally be built using the following products:
however, additional products may be required to completely define and model it. Furthermore, this example may also be defined and modeled using components from the following product combinations:
The combination of COMSOL® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. Particular functionality may be common to several products. To determine the right combination of products for your modeling needs, review the Tabella delle Funzionalità and make use of a free evaluation license. The COMSOL Sales and Support teams are available for answering any questions you may have regarding this.