Thanks Jim, Nice website I bookmarked that. I like the comment on the page.
"You can build a reflectometer using a single directional coupler to form a reflectometer and two power sensors, but it is not recommended (use the dual-directional coupler you cheapskate!)"
Guess I will go with 2 couplers. I will see if I can find a coupler with better directivity (Is directivity the isolation between the 2 coupled ports?). I think internal terminations will also be better.
This part on the website confuses as it pertains to terminations. The part in red, is that to say the coupled port should be un-terminated? Im confused.
Bi-directional property
Any directional coupler is bi-directional, that is, it performs equally well when the signal is incident on port 2 versus port 1, but the coupled and isolated ports flip. All direction couplers are bi-directional, unless you terminate one of the ports. Consider the coupled-line coupler below. Port 4 is the coupled port when a signal is incident on port 1, and port 3 is the coupled port when a signal is incident on port 2.
Thanks