HP 54520 Series - Page 266

Specifications and Characteristics
Operating Characteristics
Selectable Windows Three windows are selectable: Hanning, for best
frequency resolution and general purpose use; flattop, for best
amplitude accuracy; and rectangular, for single-shot signals such as
transients and signals where there are an integral number of cycles in the
time record.
Maximum Displayed Frequency 5 Hz to 500 MHz
selectable (real-time acquisition). Display is from dc to a selectable
upper frequency, in steps from 5 Hz to 500 MHz. Maximum frequency
displayed is 1/2 the sample rate.
Window Characteristics The window characteristics are shown below.
Highest Side 30B 6dB Scallop
Lobe Bandwidth Bandwidth Loss
Window (dB) {bins) {bins) {dB}
Rectangular
-13
0.89
1.21
3.92
Hanning —32 1.44 2.00 1.42
Flattop ~70 3.38 4.17 0.005
Highest Side Lobe The minimum attenuation in the stop band. It indicates the
level of leakage present in the filter; that is, how high the skirts are in relation to
the main peak.
3 dB bandwidth The width of the peak at a level 3 dB down. A narrow 3 dB
bandwidth helps in separating frequency peaks that are close together.
6 dB Bandwidth The width of the peak at a level 6 dB down.
Bins The distance between frequency points. One bin equals the resolution.
Scallop Loss The attenuation of the peak half way between bins. The scallop
Joss determines the amplitude accuracy of a window. It measures the attenuation
of a signal that falls between frequency bins versus one that is exactly on a
frequency bin.
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