Spectrum Analysis
R&S
®
Scope Rider RTH
121User Manual 1326.1578.02 ─ 12
Window type
Windowing helps minimize the discontinuities at the end of the measured signal inter-
val and thus reduces the effect of spectral leakage, increasing the frequency resolu-
tion.
Various different window functions are provided in the R&S RTH to suit different input
signals. Each of the window functions has specific characteristics, including some
advantages and some trade-offs. Consider these characteristics carefully to find the
optimum solution for the measurement task.
Table 6-4: Window type characteristics
Window type Frequency
resolution
Magnitude
resolution
Measurement recommendation
Rectangular Best Worst Separation of two tones with almost equal amplitudes
and a small frequency distance
Hamming
Hann
Good Poor Frequency response measurements, sine waves, peri-
odic signals and narrow-band noise
Flat-Top Poor Best Accurate single-tone measurements
Blackman Worst Best Mainly for signals with single frequencies to detect har-
monics
Accurate single-tone measurements
Remote command:
SPECtrum:FREQuency:WINDow:TYPE on page 355
SPECtrum:FREQuency:WINDow:FACTor? on page 355
Trace mode (Clear/Write/ Max Hold/ Min Hold/Average )
Determines which of the acquired data is displayed. Several traces can be displayed in
parallel, but at least one mode must be selected. By default, the "Clear/Write" mode is
selected.
As soon as a new mode is selected, statistical evaluation is restarted.
To clear the results for previous measurements used for statistical evaluation, select
Reset.
"Clear/Write"
The currently measured value for each frequency is displayed.
"Max Hold"
The maximum value for each frequency over all measurements is dis-
played.
Using the max hold trace mode is a good way to detect intermittent
signals or the maximum values of fluctuating signals, for example.
"Min Hold"
The minimum value for each frequency over all measurements is dis-
played.
Using the min hold trace mode is a good way to highlight signals
within noise or suppress intermittent signals.
"Average"
The average value for each frequency in the Clear/write trace over
the specified "Number of Averages" is calculated.
Averaging reduces the effects of noise, but has no effects on sine sig-
nals. Using the trace averaging therefore is a good way to detect sig-
nals in the vicinity of noise.
Spectrum Mode (Option R&S RTH-K18)
To Next Page
Loading...
