## Re: [Qucs-help] Rectangular waveguide impedance calculation

 Re: [Qucs-help] Rectangular waveguide impedance calculation From: roucaries bastien - 2011-03-28 07:55:29 On Fri, Mar 25, 2011 at 5:10 PM, Julien Hillairet wrote: > Dear Qucs staff, > > First of all, thank you for providing the world this very nice tool ! It is > of great interest, especially for education but also for research (not > everyone can afford ADS or Ansoft Designer...) > > My question is related to the rectangular waveguide line transmission > calculator. If the attached picture, I've calculated the properties of a > WR284 waveguide (72mm x 34mm) @ 3.7GHz. Qucs gives a characteristic > impedance of Z0=430.4 Ohm. > > However, taking the analytical equations, I obtain (this is matlab code) > > % TE characteristic impedance of a rectangular waveguide > a = 72e-3; % [m] height > b = 34e-3; % [m] width > c = 299792458;       % [m/s] light velocity > m = 1; > n = 0;         % for mode TEmn = TE10 > f = 3.7e9;      % [Hz] > > lambda = c / f; >     k = 2 * pi / lambda; >  nabla = 119.9169832 * pi; >  beta = sqrt( k^2 - (m*pi/a)^2 - (n*pi/b)^2 ); > Z_TEmn = k * nabla / beta > > > --> Z_TEmn = 455.7152 Ohm > > Could you explain we what is calculated in Qucs  ? (and how ?) Could you try the simulation of TE10 waveguide ? Or it is only linecalc ? Bastien > Best regards, > > Julien Hillairet > > ------------------------------------------------------------------------------ > Enable your software for Intel(R) Active Management Technology to meet the > growing manageability and security demands of your customers. Businesses > are taking advantage of Intel(R) vPro (TM) technology - will your software > be a part of the solution? Download the Intel(R) Manageability Checker > today! http://p.sf.net/sfu/intel-dev2devmar > _______________________________________________ > Qucs-help mailing list > Qucs-help@... > https://lists.sourceforge.net/lists/listinfo/qucs-help > >