Another approach would be to use directional couplers and diode
detectors to measure forward and reflected power. The combination of
low power and f2GHz means care is needed.

Try eBay, searching for "directional coupler" and also searching for
"sma" to find things. It's amazing how much good RF stuff you can find
on eBay.

If you want SWR, that means forward and reverse measurements and some
slightly-more-than-minimal amount of calibration. Two directional
couplers, two diodes. I did simple calibration for a similar problem
using a SMA tee, putting two 50 ohm terminations on the tee to give a
known mismatch.

If all you want is minimize-the-power-coming-back-in-my-face, one
coupler and a diode should do it.

Depending on your measurement capabilities, you might want gain blocks
between the coupler(s) and diode(s) -- lots of Mini Circuits stuff on
eBay, and other "gain blocks" -- search for "sma amplifier". Might
also want a circulator/isolator between your output gadget and the
couplers

Analog Devices have a log amp (AD8361) good up to 2.5 GHz, which puts
out an equivalent RMS signal. Evaluation boards are available (and
highly recommended unless you're quite good at layout and fabrication
at such frequencies) but go for $100. Take a look at the spec sheet
http://www.analog.com/UploadedFiles/...12AD8361_b.pdf
and see if that will do it.

73--

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Namaste-