H-plane waveguide T-junction(question)

hi

At the begining,I wanted to design a power divider using H-plane waveguide T-

junction and now I have known it. We can get good matching at input port through

adding a post. But I find that this structure(H-plane waveguide T-junction) has bad

isolationin at two output ports,so it can not be used in power combiner. But I have

no method to improve it.Help me please.

Best regards
Kezman

Added after 2 minutes:

P.S.

I want to use this structure(H-plane waveguide T-junction) design power combiner.

Dear Kezman,

You can use a magic-tee whose E-port is terminated using dummy load. The catch is such devices can not be easily designed to provide wideband performance. As far as I can remember, you should avoid the standard configuration, and go for a folded type. Thus the symmetrical output ports will be parallel and the H-plane divider will be like a bifurcated waveguide. Please study the following patent:

http://www.freepatentsonline.com/3375472.pdf

The type that I mean is depicted in Fig. 2, 3, 7 and 9.

Good luck

wave-maniac

Dear wave-maniac
Thank you again.But there are several question on me:

1. I don't understand your meaning of dummy
load.What's that?How can implement it in simulation
as HFSS and in practice?

2. I have a question about measure of S parameters.Commonly we get S parameters through adding matching load,as like 50ohm.For example,I can get good S11 through adjusting the post of the H-plane T-junction in HFSS.In this case,we can say that we get good matching at input port,however,I don't know which characteristic impedance the input port is matched to,50ohm or not.

P.S. Can you tell me your email?Thanks!

Best regards
Kezman

1) That is waveguide matched-load. In HFSS, you can just use a port, which will simulate a perfectly matched load.
2) If you do not normslize the calculated scattering parameters to 50-Ohm, then you're matching for the waveguide impedance, not 50-Ohm.

BTW, you can find many of the info by googling around.

Good luck

Dear wave-maniac

If I simulate a waveguide configuration(H-plane T junction) in HFSS with default setting of waveport,how much impedance I have matched at input port?50ohm,waveguide impedance or some others?Please tell me,thanks!

Best regards
Kezman

Added after 4 minutes:

P.S. How to deal with dummy load at E branch of magic-T in practice?

As to the first question: Waveguide impedance. For the E-port, just assign a port to it. That's it.

use fractal diaphragms in the H-arm...........