# Need help with electromagnetics

1. Apr 14, 2005

### vptran84

Hi,

I was given this problem, but i just dont know where to start, i looked through numerous websites, and 3 books as reference, but i can't find anything that is related to this problem. Any help would be appreciated.

here is the problem:

A microwave structure has the cross section shown in the figure below. The
outside tube is grounded and the center conductor is at V = 10V. Use the finite element method to solve for the voltage V in the space between the conductors.(Assume that the length is very long.) There is a picture that goes with this problem, but i dont know how to load it. So im gonna describe it. There is a small square inside a rectangle. the small square is the center conductor, and the rectangle represents the outside tube that is grounded. the length and width of the small square inside is A=2mm, and the width of the outside rectangle is B=8mm, and the length of the outside rectangle is C=10mm.

2. Apr 15, 2005

### Astronuc

Staff Emeritus
Do you have an example of Maxwell's equations (integral form for FE) for the geometry of which you describe?

Try to find a book like this - Volakis, J. L., Chatterjee, A. and Kempel, L. C.
Finite Element Method for Electromagnetics: Antennas, Microwave Circuits, and Scattering Applications
IEEE Press and Oxford University Press, New York, 1998, 368 pp.

Assign the appropriate potential/charge to the small square block.

Do you have a text on electromagnetics or microwave cavities/magnetrons?

3. Apr 17, 2005

### vptran84

hi,

i figured out how to do this problem using excel...it only took me 2 hours LOL, but i finally figured it out.

Thank you for your comment...i will try to look for the particular book...the only textbook that im using rite now is Fundamentals of Engineering Electromagnetics by David K. Cheng.