Natural Science Forum / Physics / Electromagnetism / November 2004

premise: I'm a chemist with little physics background;
the following is not homework, just a curious problem
that I figured out for myself; my English is weak,
to be fair, I learnt it too late.

First of all, I am an electronics engineer, not good at physics.  So
be kind please.
Two books show quite different formula to calculate patch antenna
feeding impedance.   Want to have guru's opinion.

Good evening,
It is well known that FDTD algorithms present numerical dispersion problems.
At what angles is the algorithm likely to be the most susceptible?Are there
any simple methods for overcoming this, without having to resort to changing

You are invited to review my Ph.D dissertation at the University of
Texas at Austin, "A General Solution to the Unrestricted Three Body
Problem of Celestial Mechanics."   There are seven sections with a
total of fifty papers.  Individual links and a summary of the whole

I'm trying to reconcile div(B)=0 in free space with my visualization of a
photon.
The setup is that a plane polarized photon is traveling along the z-axis.
E-field parallel to the y-axis. H-field parallel to the x-axis. The field

Can anybody provide me an answer or a pointer.

I need information about the "maximum current density" of the conductors.
(not superconductors).
I am not sure how this limit is defined.
Data, but also concept, definitions, standards, etc.

at the moment I am trying to do EM-simulations of waves travelling
towards a dielectric half-space with a rough surface.
Due to the constraints coming from the used frequency and the surface
roughness parameters only a FEM or a MoM approach seems to make sense.