That is to say, the scanning time is proportional to SPAN and is inversely proportional to the square of RBW. Usually when we do not focus on noise, the VBW can be set to a value greater than or equal to RBW. The second factor means that each selection The time required depends on the smaller value between RBW and video bandwidth (VBW). In this formula, the meaning of the first factor is the number of frequency selections under SPAN, each step is 1 / k of RBW, to ensure the accuracy of amplitude measurement. Here is the equation governing the sweep speed: Sweep time is the length of time it takes to sweep the detector from the start to the stop frequency. Why not use the smallest RBW setting for all measurements? Smaller RBWs provide finer frequency resolution and the ability to differentiate signals that have frequencies that are closer together. In spectrum analysis, the resolution bandwidth (RBW) is defined as the frequency span of the final filter that is applied to the input signal. The bandwidth of a measurement defines the range of frequencies that were used for the measurement. For example, the bandwidth of transmission signal is the span of frequencies that the transmission occupies. Resolution Bandwidth (RBW)īandwidth is defined as the span of frequencies that are the focus of a particular event.

In this application note, we will introduce resolution bandwidth (RBW) and video bandwidth (VBW) and how they affect measurements.

There are a number of common adjustments available with many modern analysers that can optimize performance for a particular application. Spectrum analysers are useful tools for broadcast monitoring, RF component testing, and EMI troubleshooting.

Spectrum bandwidth