Hi, Denmark:
Ansoft's HFSS is very expensive (about $50,000). We also have ANSYS lincese and have solved some HF problem using ANSYS. But when the shape of model become complicated, ANSYS can not go through because of meshing problem. Trust me, if we can totally understnad ANSYS, it can solve...
For junction problem of rectangular waveguide, in junction area, both dominant mode and higher mode are considered using mode match(or something else, FEM,Equivalent circuit). After that, when we compare simulation data with experiment data, only dominant data is involved. The reason for this is...
My point is that this is because of normalization of amplitude. From book:
Reinhold ludwig & Pavel Bretchko
"RF Circuit Design Theory and Applications"
Page 171-172
You can find solution there.
By the way, I have a question here,too. Does somebody know why we should normalize here? I...
What is basic theory behind HFFS? Maybe mode match theory (or somethig else, for example,equivalent circuit) is exactly foundation of this simulation tool. Some papers show that their results using mode match fit very well with results from HFFS.
What do you mean "Fortunately, with HFSS mode matching is dead for the practicing engineer today"? Do you mean that mode matching is not useful in mocrowave indurstry? I know HFSS is a simulation software but have never used it.
S Matrix including higher modes can improve accuracy. We can find a lot of papers about numeric simulation about microwave juntion. In the before, only dominant mode was considered. Now almost everyone considers higher modes. Maybe this approach is only for academic purpose and it is hard to...
There is a good paper for your quesiton:
Haim Haskal, "Matrix Description of Waveguide Disdcontinuities in the Presence of Evanescent Modes,"
IEEE Transactions on Microwave Theory and Techniques,
pp. 184-188, March 1964
