[Getdp] Eigenmodes of waveguide?

[Cezary Sydlo]

Hi,

i would like to use getdp to calculate cut-off frequencies off hollow
waveguides and (of course) generate some nice field-pictures with it.
But i have no idea how to implement it in getdp :-( ... please help ...

The math behind it is the helmholtz equation:
div(grad(A)+k^2*A=0, where k=omega*sqrt(mu*eps) is the wavenumber and A
the vectorpotential

For calculation of TE-Modes you choose the approach:
E=rot(A), where E is the electric field, this implies
H=-1/(i*omega*mu)rot(rot(A))

and similar for TM-Modes:
H=rot(A),
E=1/(i*omega*eps)*rot(rot(A))

that much for the math ...

boundary conditions for the waveguide would be Et=0 ... 

Thank you and
Greetings
Cezary
-- 
Dipl.-Ing. Cezary Sydlo
Institut fuer Hochfrequenztechnik, TU Darmstadt
Merckstrasse 25, D-64283 Darmstadt, Germany
Tel : ++49  (0) 6151 16 2662
FAX : ++49  (0) 6151 16 4367
E-Mail: c_sydlo at hf.tu-darmstadt.de