Those "stairs" are quarter wave impedance transform sections. You choose the wave impedance to match the end impedance. Mathaie, Young, and Jones have a section on such transformers. Other older papers exist with titles like "chebychev impedance transformers", etc.
Those "stairs" are quarter wave impedance transform sections. You choose the wave impedance to match the end impedance. Mathaie, Young, and Jones have a section on such transformers. Other older papers exist with titles like "chebychev impedance transformers", etc.
Thank, but I can not find "chebysev impedance transformers", do you know, where can I find "good" theory? How can I calculate the dimensions of the stairs?
Are you sure, that is it QUATER wave impedance transform sections?
Be aware, they spell chebychev differently in different countries.
I would bet they are quarterwave steps. They could be other lengths, like 3/4 wave, but you would end up with 3X less bandwidth for the impedance transform(I think).
Yes, you are right, the wave impedance in the TE10 mode does not depend on b(height). Never the less, this is how it is done. I would refer you to Mathaei, Young, and Jones section 6.08 (pages 300 - 304) for an example of matching two equal width waveguides by means of stepped height quarter wave sections.
maybe you do not think of it as actual quarter wave impedance sections, but rather as a series of height discontinuities spaced by quarterwave? Theory of small reflections?