coax to waveguide transistion

[asgant]

hii..
i want to model waveguide to waveguide through coax ..
Intially i started doing wavegudie to coax transistion..i modeled it but the field pattern is not good..the wave is not transfering to waveguide..there is wrong with my coax model..so could anyone pls help me how to model the coax to waveguide ..
thanks in advance

 

[Externet]

This is as much as I know, but leaves the distance from the end of the coaxial to the 'top' wall of cavity unanswered, and lateral spacing. As soooo many incomplete tutorials and text books, omitting details. :-(

 

[asgant]

thanku for reply.there is wrong with my model..because the wave is not transfering into waveguide as shown in figure..i want to know the model of coax ..i mean the outer cylinder diameter is subtracted from waveguide..the inner cylinder is subtracted from outer cylinder..
do you have any idea regarding modelling in hfss..

 

[Abhishekabs]

Is your Teflon extended till waveguide?
outer metal cover should end @ entrance of waveguide, where it shorts with waveguide.
only teflon & inside conductor go till waveguide.
Also did you fill inside of waveguide with Air?
If you have assigned correct excitation, then it should work.
line should be drawn withing teflon boundary. touching inside & outside conductor.

 

[asgant]

Is your Teflon extended till waveguide?
outer metal cover should end @ entrance of waveguide, where it shorts with waveguide.
only teflon & inside conductor go till waveguide.
Also did you fill inside of waveguide with Air?
If you have assigned correct excitation, then it should work.
line should be drawn withing teflon boundary. touching inside & outside conductor.

hii abhishek..
do u mean integration line??i defined the line touching diamter of inner conductor to outer conductor..
teflon is extended till waveguide..i dont know where the problem is..

 

[jiripolivka]

This is a quite difficult task. Many before you tried to calculate and model such transition... and failed. The problem has been solved by trial and error, not by modeling. This is why GOOD transitions are offered commercially at a good price.