Window Bandwidth

In many spectrum analyzers, the final IF filter determines the resolution bandwidth. In the Keysight 89600 VSA, the selected window type determines the resolution bandwidth filter shape. The window type, combined with the time record length, also determines the width of the resolution bandwidth filter.

Therefore, for a given window type, specifying resolution bandwidth will directly affect the length of the main time record. Conversely, specifying the main time record length will affect resolution bandwidth. The relationship between window type, time record length, and resolution bandwidth is explained in the following section.

Important relationships

The 89600 VSA defines the window bandwidth as the Equivalent Noise Bandwidth (ENBW) of a window's filter shape. The relationship between the normalized window bandwidth, time record length, and resolution bandwidth is listed below:

Some useful equations help explain the relationship between time record length and time record size:

Normalized ENBW
Uniform	1
Hanning	1.5
Gaussian Top	2.2153
Flat Top	3.8194
Blackman-Harris	2.0044
Kaiser-Bessel	2.0013
Gaussian	2.0212