Waveguide 3dB coupler? Branch line coupler?

Hi,

do you know, how can I do 3dB coupler? I have waveguide R120 (WR75) - 9.8-15 GHz.

For example this:

but I have not the theory. Or other solutions?

Can you help me?

Thank!

EDIT:

Do you know, how can I design branch-line coupler in waveguide?

Hi, you repeat to post same topic in this forum.

It is possible,sorry, but I can not find answer ;)

patent 3258879. There is an earlier one by riblet with a center post too, search it.

U can try:

- a "T" divider (if u don't need low coupling between output ports)
- magic "T" (u have a further freedom degree)
- a branchline (4 ports, advantages on isolation between putput ports and on reflection at the input port)
- Wilkinson divider (similar to the branchline but more compact)

U should find everything on the most common books.

Let me say if it helps.

Regards,

Lupin

[/COLOR]Are you sure, that "Apparatus for grinding contact lenses" is solution for me?

---------- Post added at 13:29 ---------- Previous post was at 13:24 ----------

"T"- there is problem with S11.... and I need matching all port, "T" is have not matching of 2 port.

I think, that the coupler is better solution for me, divider is not good.

---------- Post added at 13:40 ---------- Previous post was at 13:29 ----------

If you do not understand me, see the picture:

Divider

and "S" parameter is:

S

S21 and S31 - are good - 3 dB, S11 < -25dB - good. But S22 and S33 is very bad.....