Hey Tom,

Thanks a lot, I'm going to download this software and have a look. My mind
was the power should be limited very low with PCB striplines, and I would
like to design something up to about 100W.

Stephane

"Tom Bruhns" wrote in message
m...
I'm not sure what's in current versions of the ARRL VHF/UHF manual,
but I know that older ones have articles on building SWR bridges. You
can just delete the detectors if you want to use them as directional
couplers. Also, you can download "RFSim99" for free, and you will
find in it a little design ap for directional couplers, in microstrip,
stripline, transformer-type, lumped and transmission line. The ap is
under "tools--components--coupler" in the pulldown menus. Note that
the microstrip and stripline assume the coupler is 1/4 wave long for
the given coupling--something the ap fails to point out.
Interestingly, 1/4 wave couplers (microstrip or stripline or the like)
give the same coupling at 3/4 wave...in other words, at the third
harmonic, which is useful for 146MHz and 440MHz. This is not true of
the lumped. The transformer style depends on the bandwidth of the
transformers.

Cheers,
Tom


"Stéphane Rey" wrote in message
...
Hello,

I'm looking for documentation explaning how to design and built
directional
couplers for 2m and 70 cm application.

I've found a lot of links for the theory but nothing explaning how to
compute the parameters and built it .

Any suggestion appreciated

Thanks
Stephane, F1TJJ