microstrip coupler detector

One would start by defining what the exact frequency range is, the coupling value, maximum input power, altitude, the directivity required, and the media desired (coax, waveguide, microstrip, stripline).

For the detector, one would define what is the dynamic range required and response time.

I wanna use microstrip circuit! it's about 20W PA
the detector is used to test it!

Added after 3 minutes:

Can you give me some help,thanx a lot!

use overlay coupler, about 20dB (so u gona have good directivity)
put att after the coupler, and then Analog devive comp. made agood ditector 0-18GHz. (i teset it, and it is ok).

thank you very much

Added after 14 minutes:

but how to design a overlay coupler and what's mean of "att"...........
I'm sorry of less know about this!

att is attanuator

to make an overlay coupler u should put dielectric metiral on the coupler

But I still don't konw how to choose and design the detector with diode!
;(

at what freq ?

X band about 9-10GHz
hoho~
help me pls