First, a surface current is an approximation. Really, only volume currents exist. In metallic antennas, the surface current is an actual electric current that is induced by an applied electromagnetic field. The electric field pushes charges around. Pretty much any simulation package that handles metals will be able to visualize the surface current for you. The method of moments, for example, works by calculating the surface current on conductors.

Now, you asked about a dielectric antenna. There are still currents on dielectrics, but I think it makes less sense to look at them. Charges are bound so you only get the displacement current. That is, a shifting of charges around their atoms. When the charges are displaced like this, the material is said to be polarized. All of this is accounted for by the permittivity of the material, so it is rare to see a modeling tool visualize the displacement current. You can certainly back calculate the polarization, and therefore displacement current, but I am not sure how useful it is for a dielectric antenna.

If you want more information on material polarization issue, see Lecture 2 here:

http://emlab.utep.edu/ee5390em21.htm

Hope this helps!

First, a surface current is an approximation. Really, only volume currents exist. In metallic antennas, the surface current is an actual electric current that is induced by an applied electromagnetic field. The electric field pushes charges around. Pretty much any simulation package that handles metals will be able to visualize the surface current for you. The method of moments, for example, works by calculating the surface current on conductors.

Now, you asked about a dielectric antenna. There are still currents on dielectrics, but I think it makes less sense to look at them. Charges are bound so you only get the displacement current. That is, a shifting of charges around their atoms. When the charges are displaced like this, the material is said to be polarized. All of this is accounted for by the permittivity of the material, so it is rare to see a modeling tool visualize the displacement current. You can certainly back calculate the polarization, and therefore displacement current, but I am not sure how useful it is for a dielectric antenna.

If you want more information on material polarization issue, see Lecture 2 here:

http://emlab.utep.edu/ee5390em21.htm

Hope this helps!

Simulate your antenna in CST. CST will visualize surface current and e-field associated with it.

In order to visualize surface currents, you need either a formulation of the problem in terms of surface currents (i.e. boundary integral equations, usually solved by method of moments) or the boundary values of the field on the surface (determined by postprocessing the field data that the solver generated). So it really depends on the solver you use for the antenna.

Surface currents sometimes have physical significance and sometimes are just fictitious quantities, called "equivalent currents" or "fictitious currents". Real physical meaning is attributed only to electric surface currents flowing on an (ideally) perfectly conducting body (PEC body). If the body is not PEC, the currents can never concentrate on its 2-dimensional surface, but are always volume currents. However, if the body conducts very well, a surface current is a good approximation to the realistic volume currents. On the other hand, surface currents on dielectric surfaces, (either electric or magnetic currents) are always "equivalence currents". They are calculated by the tangential component of the boundary values of the magnetic or electric field respectively and can be used to replace the antenna as equivalent sources of radiation.

According to the equivalence principle, if you were to replace the antenna by the equivalent currents on its surface, the radiated field would be the same as that of the original antenna. So these surface currents are the electromagnetic analog of Huygen's principle, which roughly states that the points on a closed surface representing a wave front act as secondary sources of waves; the full wave propagation can be reconstructed from these secondary sources without any need to know the primary source of the wave. If you know the boundary values of the fields on a closed surface (like on your antenna), you can always reconstruct/predict the wave propagation inside and outside this surface. The surface currents are just a convenient visualization of this mathematical/physical principle, since it is more appealing to our physical intuition to consider "currents" as sources of fields rather than abstract boundary values. For more information you could consult Balanis "Advanced Engineering Electromagnetics".

The physical significance of surface currents on (semi) conductors versus 'volume' currents:

A 'send' antenna has two types of energy flow:

One needs two types of field waves (electric and magnetic) that have the same phase (no phase difference) in order to achieve one directional energy flow. The dipole antenna is not that straightforward to understand, do the fields have no phase difference? It seems that the antenna fields associated with the volume 'drift' currents are 90 degrees out of phase, such that the dipole antenna is like a passive oscillating LC circuit which does not radiate. For this reason I assume that surface currents are essential to understand both flows of energy.