Waveform analysis
R&S
®
RTP
302User Manual 1337.9952.02 ─ 12
The resulting expression could be, for example: rescale(Ch1Wfm1,3,4)
7.3.5 Filters
The R&S RTP provides several ways to filter the input signal:
●
Lowpass filter by selecting a bandwidth limit in the acquisition path (vertical chan-
nel settings)
Available with probe adapter R&S RT‑Z1M, see Chapter 5.6.11.1, "Channel set-
tings with connected adapter", on page 190
●
Digital lowpass filter
See Chapter 5.5.5, "Digital filter setup", on page 163
●
FIR filter to create a filtered math waveform (lowpass, highpass, bandpass)
You can set up a FIR-filtered math waveform in the basic math editor, or in the
advanced editor. Both ways are described below in this chapter.
7.3.5.1 FIR filter in the math setup
Access: "Math" > "Setup" tab > "Filter" tab.
The finite impulse response filter is a filter to create filtered waveforms with lowpass,
highpass, or bandpass. The filter requires additional settings.
●
"Type": defines whether the FIR filter is a highpass, lowpass, or bandpass/band-
stop (= "User defined") filter.
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"Cut-Off": sets the limit frequency for the highpass or lowpass FIR filter.
●
"Characteristics": relevant for lowpass filter. Defines whether it has a Gaussian or a
rectangular shape. The highpass is always Gaussian.
●
"Select filter file": relevant for bandpass/bandstop filter. Opens a file dialog to select
the file with the filter coefficients.
Cut-off frequency for lowpass FIR filter
The cut-off frequency depends on the horizontal resolution and the filter characteris-
tics. The frequency for the lowpass filter can only be set in this range:
Mathematics