# RF measurement setup

I'm trying to take a simple measurement of ~2.4 GHz (WiFi land) with an RF spectrum analyzer (Tektronix RSA607A) but have so far been unsuccessful. On the RF In port I have an N-BNC adapter connected to a meter-long BNC cable, which is connected to a BNC-SMA adapter and WiFi antenna. All items in the chain are spec'd at $$\50 \Omega\$$.

All I am able to measure, however, is noise. I tried using several different cables, reattaching all connections, and even plugging the whole shebang into a Tektronix MSO3054's RF port. I 'know' the spectrum analyzer is working -- I plugged a waveform generator into RF In by way of a BNC cable and said N-BNC adapter, and the analyzer successfully measured a 1 MHz sine wave.

I'm sure it's something trivial, but we don't have any RF-experience persons around to consult. Does this setup appear obviously incorrect somewhere?

• You might need a pre-amp to boost the signal level. Mini circuits is a good place to look for one. – EE_socal Nov 16 '18 at 20:15
• BNC connectors aren't a great choice at microwave frequencies. What are you using to make the wifi transmit? Can you try some other radio source (even at a very different frequency) to make sure you are using the analyzer correctly? Has the analyzer been damaged, perhaps by someone wiring it to a source that has a DC offset? – Chris Stratton Nov 16 '18 at 20:58
• @ChrisStratton Ah, forgot to add -- I tried it with an arbitrary waveform generator, too, with success. Edited my answer. I will try other sources -- currently I am just trying to measure ambient WiFi and a nearby IoT device (~1 m away). – calcium3000 Nov 16 '18 at 21:07
• @ChrisStratton Also, I am going to purchase an N-SMA adapter to plug the antenna 'directly' into the spectrum analyzer to shorten the chain a bit. – calcium3000 Nov 16 '18 at 21:08
• Is there anyone in your facility familiar with the usage of this gear? Seems like you have a lot of pricey toys, some of them easily damaged. Typically a place that buys these has people who know how to use them, both from a functional perspective and a not blowing up the front end one. – Chris Stratton Nov 16 '18 at 21:09