Figure 2-1 1 Khz Signal Separation; Figure 2-2 2 Khz Signal Separation - Agilent Technologies 8560E User Manual

Making Measurements
Example 1: Resolving Closely Spaced Signals (with Resolution Bandwidth)
To resolve two signals with a frequency separation of 2 kHz, a 1 kHz
resolution bandwidth again must be used (see Figure 2-2). Since the
spectrum analyzer uses bandwidths in a 1, 3, 10 sequence, the next
larger filter, 3 kHz, would exceed the 2 kHz separation and thus would
not resolve the signals.
Keep in mind that noise sidebands (phase noise) can also affect
resolution.
Figure 2-1 1 kHz Signal Separation
Figure 2-2 2 kHz Signal Separation
52 Chapter 2