Datasheet

Spectrum Analyzer Software Reference

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4.1.4 Band Width

The band width determines the frequency resolution of a measurement. The general rule is that a larger

frequency range of interest (span) requires a larger bandwidth.

In Easy RF mode, these settings are managed automatically, and the user does not need to change them.

However, it might be necessary under certain circumstances to apply special settings. The Easy RF mode

can be turned off by clicking the Easy RF mode button (see Figure 10).

Figure 10. RF Settings Tab, RF Mode

Two different settings are then available and closely linked to each other (see Figure 11).

Figure 11. RF Settings Tab, Band Width

4.1.4.1 Filter Step Width

The SA430 has an analog heterodyne receiver that is digitally controlled. The filter step width (FSW)

determines the frequency distance between two measured power levels. As every measured level is

shown on the graph it also gives the frequency distance between two points in the graph. The number of

points is defined by span divided by the FSW plus one.

A number that is small compared to the span gives more samples but takes more time to measure.

4.1.4.2 Resolution Band Width

The resolution band width (RBW) gives the frequency size of the input filter that is applied to the input

signal. This filter is applied at each measured frequency point.

A small number gives better frequency resolution but covers a smaller frequency area. For larger

frequency spans, therefore, it is better to have a larger RBW.

RBW and FSW depend on each other. To avoid losing signal information, the distance between two

measurements (FSW) needs to be smaller than the filter width RBW.

4.1.5 Settings

To make repetitive tasks easier, all RF settings can be exported and imported to an application specific

XML file. The settings are not tied to this computer or equipment so a measurement setting can be shared

easily with others.

Figure 12. RF Settings Tab, Settings

An undo to last settings button is available to quickly go back to the last setting.

Spectrum Analyzer (MSP-SA430-SUB1GHZ) SLAU371A– September 2011– Revised November 2011

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