From: roucaries bastien <roucaries.bastien+qucs@gm...>  20110328 07:55:29

On Fri, Mar 25, 2011 at 5:10 PM, Julien Hillairet <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 = 72e3; % [m] height > b = 34e3; % [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/inteldev2devmar > _______________________________________________ > Qucshelp mailing list > Qucshelp@... > https://lists.sourceforge.net/lists/listinfo/qucshelp > > 