## FEKO ANTENNA MODELLING: EQUIVALENT SOURCES (Spherical Mode)

In this tutorial, we performed the equivalent source antenna modeling using spherical mode source.

Introduction:

With growing communications, nowadays there are increasingly sophisticated antenna systems with associated electronics aboard aircrafts. Placement of antennas for various systems is a challenge due to the coupling between the antennas and the resulting co-site interference.

Advances in electromagnetic (EM) simulations have significantly improved the design process to assess coupling between various antennas resulting in reduced testing time and costs. While it is ideal to use the actual simulation models of antennas during the design process, system designers normally do not have access to the simulation models (or CAD models) of the antennas for various reasons, such as antenna vendor confidentiality etc. It then becomes essential that actual antenna simulation models to be replaced with accurate representation using equivalent sources, such as near fields, far fields etc

Equivalent Source Simulation (Spherical Mode) Results:

An “equivalent” source is a numerically equivalent (simulated or measured) of a complex source. Significant reductions in computational requirements are achieved when solving a complex problem using an equivalent source. To demonstrate this equivalent source concept, we choose a Horn Antenna Design (which is working at 1 GHz) from Altair Feko’s Component Library. Figure 1 depicts the horn antenna and its detailed dimensions. Figure 2(a) and (b) depict the real horn antenna and equivalent source antenna (Spherical Mode). Figure 3 (a) and (b) depict the 3D far field pattern results of the real horn antenna and equivalent source. Figure 4 depicts the comparison plot of real and equivalent source antenna (Spherical Mode) results.

Figure 1

Real Antenna                                                   Equivalent Source (Spherical Mode)

Figure 2(a)                                                            Figure 2(b)

Real Antenna                                           Equivalent Source (Spherical Mode)

Figure 3(a)                                                            Figure 3(b)

Figure 4

A detailed step by step instructions on this tutorial is presented in the below video.