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Dear all,
I'm puzzled by the result given by HFSS (v12 or v13) in a simple rectangular waveguide case.
When modelling a rectangular waveguide which cross-section dimensions are 72mm x 34 mm (WR284) and let say a 200mm length, at 3GHz, HFSS solution data Z0 are :
- using Zpi (default) integration line : Z0=304.7 Ohm
- using Zpv integration line : Z0=494 Ohm
However, using analytical expression in this simple case (for TE mode), I find :
gives Zc = 523.2295 Ohm
What am I misunderstanding here ?
Best regards,
I'm puzzled by the result given by HFSS (v12 or v13) in a simple rectangular waveguide case.
When modelling a rectangular waveguide which cross-section dimensions are 72mm x 34 mm (WR284) and let say a 200mm length, at 3GHz, HFSS solution data Z0 are :
- using Zpi (default) integration line : Z0=304.7 Ohm
- using Zpv integration line : Z0=494 Ohm
However, using analytical expression in this simple case (for TE mode), I find :
Code:
% waveguide cross-section dimensions
a = 72e-3;
b = 34e-3;
% frequency
f = 3e9;
% mode indexes
m=1; n=0;
%% -------
c0 = 299792458;
k0 = 2*pi*f/c0;
omega = 2*pi*f;
mu0 = 4*pi*1e-7; eps0 = 1/(mu0*c0^2);
Z0 = sqrt(mu0/eps0);
% guided wavenumber
beta = sqrt(k0^2-(m*pi/a)^2-(n*pi/b)^2);
% characteristic impedance of the TE mode mn
Zc = k0.*Z0./betaWhat am I misunderstanding here ?
Best regards,