waveguide20

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waveguide20

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{  WAVEGUIDE20.PDE

 

  This problem solves for the Transverse-Electric modes of a T-septate

   rectangular waveguide.  It is a copy of WAVEGUIDE.PDE with more modes.

}  

 

title "TE Waveguide"  

 

select  

 modes = 20       { This is the number of Eigenvalues desired. }  

 ngrid=20         { we need enough density to resolve higer modes }  

 

variables  

 hz  

 

definitions  

 L = 2  

 h = 0.5               ! half box height

 g = 0.01             ! half-guage of wall

 s = 0.3*L             ! septum depth

 tang = 0.1           ! half-width of tang

 Hx = -dx(Hz)  

 Hy = -dy(Hz)  

 Ex = Hy  

 Ey = -Hx  

 

equations  

  Hz:  del2(Hz) + lambda*Hz = 0  

 

constraints  

 integral(Hz) = 0 { since Hz has only natural boundary conditions,

           we need to constrain the answer }  

 

boundaries  

region 1  

  start(0,0)  

  natural(Hz) = 0     line to (L,0) to (L,1) to (0,1) to (0,h+g)  

  natural(Hz) = 0  

      line to (s-g,h+g) to (s-g,h+g+tang) to (s+g,h+g+tang)  

            to (s+g,h-g-tang) to (s-g,h-g-tang) to (s-g,h-g) to (0,h-g)  

  line to close  

 

monitors  

contour(Hz)  

 

plots  

contour(Hz) painted  

 

end