Questions about Radar Cross Section (RCS) simulation in HFSS

Hello all,

I had a few questions concerning the example RCS problem given in HFSS, 'RCS of an ogive'. I attached the PDF that came along with the help file.

View attachment ogiveGSG.pdf

My first question concerns how the plane wave excitation is defined. From my understanding, the aim of a RCS simulation is to calculate the reflected power at a specific angle of incidence. However, in the example simulation provided by Ansys, the source has a "excitation location and/or zero phase position" of 0,0,0. Meaning the excited source is inside the object we wish to calculate the RCS for? Is this normal? Should the source always be defined in the "center" of the object you wish to examine?



My second question is two parts. What is the polarization of the incident wave in the example simulation? Its related to how the Eo vector is defined, but I dont quite understand how its operating in the spherical setup. The second part: How would I amend this simulation to yield the RCS in the cross-polarization? We are analyzing an antenna array which respond in the cross-pol (given a vertical polarization to begin with).

Thank in advance,
sami

Hello,
The incident electric field intensity is given by
.
"The source has a excitation location and/or zero phase position of 0,0,0" means that r₀ = 0,0,0.
In the example simulation, E_θ=0 and E_φ=1.
Please see also https://en.wikipedia.org/wiki/Spherical_coordinate_system