On this page there are some high power couplers presented with fair directivity. These couplers cover a rather wide frequency span from 144 up to 432 MHz or from 1296 to 2320 MHz. The coupling is rather flat and this makes it very useful with the mW meter described on this website.
Below are the construction details of these couplers:
The results are presented below. Special thanks go to Jack Smeets PE1KXH for the measurements.