Editing Spectrum analyzer (section)

=== Resolution bandwidth ===
As discussed in the '''operation''' section, the '''resolution bandwidth''' filter or RBW filter is the [[bandpass filter]] in the [[intermediate frequency|IF]] path.  It's the [[Bandwidth (signal processing)|bandwidth]] of the [[RF chain]] before the detector (power measurement device).<ref name=plsa>[http://www.piclist.com/techref/postbot.asp?by=thread&id=%5BEE%5D+TV+Tuner+Based+Spectrum+Analyzer&w=body&tgt=post&at=20120524233824apiclist.com – &#91;EE&#93; TV Tuner Based Spectrum Analyzer] {{webarchive|url=https://web.archive.org/web/20130921055149/http://www.piclist.com/techref/postbot.asp?by=thread&id=%5BEE%5D+TV+Tuner+Based+Spectrum+Analyzer&w=body&tgt=post&at=20120524233824apiclist.com |date=2013-09-21 }}, 2012-05-25</ref>  It determines the RF [[noise floor]] and how close two signals can be and still be resolved by the analyzer into two separate peaks.<ref name=plsa/>  Adjusting the bandwidth of this filter allows for the discrimination of signals with closely spaced frequency components, while also changing the measured noise floor. Decreasing the bandwidth of an RBW filter decreases the measured noise floor and vice versa. This is due to higher RBW filters passing more frequency components through to the [[envelope detector]] than lower bandwidth RBW filters, therefore a higher RBW causes a higher measured noise floor.