Rohde & Schwarz RTM2032 - Configuring the Diagrams

FFT
R&S
®
RTM20xx
112User Manual 1317.4726.02 ─ 01
To deactivate the FFT display
► Press the FFT key again, or press the "FFT off" softkey in the "FFT" menu to deac-
tivate the FFT display.
The FFT key is no longer illuminated and the previous display is restored.
To configure the general FFT display
1. Press the FFT key to activate the FFT display and open the "FFT" menu.
2. If necessary, press one of the CH1...CH4 keys to change the signal source of the
FFT calculation.
3. Press "Waveform Arithmetic" to define the mode for FFT calculation and display. The
waveform arithmetic defines whether the values are updated regularly, or whether
values from previous spectra are included in the calculation and display.
For details see "Wfm. Arithmetic" on page 116.
4. If "Average" mode is selected, press "No. of Averages" to define how many spectra
are considered for the calculation.
5. Press "Window" to define which type of function is laid over the input values. If the
input values are to be used unaltered, use the "Rectangle" window. To reduce noise,
use a bell-shaped window.
For details see "Window" on page 117.
6. Press "Y-Scaling" to select logarithmic or linear scaling of the y-axis in the FFT win-
dow (see "Y-Scaling" on page 118).
7.
Define the settings for the FFT window as described in "To configure the FFT diagram
numerically" on page 112.
8.
Define the settings of the signal vs. time window as described in "To configure the
Y(t)-window numerically" on page 114. These settings are identical to the general
trigger and scaling settings defined for the channel (see also chapter 2.2.2, "Adjusting
the Signal Input Manually", on page 20).
8.2.2 Configuring the Diagrams
To configure the FFT diagram numerically
Alternatively to configuring the FFT window numerically via the softkeys, you can use the
rotary knobs to change the settings graphically, see "To configure the FFT diagram
graphically" on page 113.
1. Press "FFT-Setup" in the "FFT" menu.
2. Define the time base extract for which the FFT is to be calculated and displayed. The
extract is defined by its width and position (see figure 8-1).
a) Press "YT-Window" to define the width of the time base extract.
Configuring and Using FFT Calculations