## FEKO ANTENNA MODELING: EQUIVALENT SOURCES (Model Decomposition)

In this tutorial, we performed equivalent source antenna modeling using Model Decomposition 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 (Model Decomposition Source) 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 through model decomposition and using an equivalent source. A Horn Antenna Design chosen from Altair Feko’s Component Library with a center frequency of 1GHz.  Figure 1 depicts the horn antenna and its detailed dimensions. Model decomposition request exports the surface currents on selected faces to a .sol file. A .sol file can be used to define a solution coefficient source in another Feko project.

Figure 1

Figure 2(a) and (b) depict the real horn antenna and equivalent source antenna (model decomposition). Figure 3 (a) and (b) depict the 3D far field pattern results of the real horn antenna and equivalent source (model decomposition). Figure 4 depicts the comparison plot of real and equivalent source antenna (model decomposition) results.

Real Antenna                                                 Equivalent Source (model decomposition)

Figure 2(a)                                                             Figure 2(b)

Real Antenna                                                        Equivalent Source

(Model Decomposition)

Figure 3(a)                                                             Figure 3(b)

Figure 4

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