Spectrum Analyzer Mode
R&S
®
Cable Rider ZPH
228
User Manual 1321.0950.02 ─ 07
Example:
Using a signal source, i.e R&S SMU to generate an LTE signal at 500 MHz (TDD
duplexing, Downlink (OFDMA), 1 frame sequence length). Connect the signal source
RF output to the RF input connector of the R&S Cable Rider ZPH.
1. Press the [SWEEP] key.
2. Select the "Trigger" softkey.
3. Select the "Gated Trigger" menu item.
To get appropriate results, you have to set the gate delay and gate length in a way
that the measurement is active during the interesting part of the signal. You can
also modify the sweep time to match the horizontal axis to the length of the signal
and thus set the gate delay and gate length parameters more accurately.
The gate delay parameter defines the time between the trigger event and the
beginning of the actual measurement. The gate length defines the duration of the
measurement, before it is interrupted and the next gate signal is anticipated to
resume the measurement.
4. Press the [SWEEP] key.
5. Select the "Trigger" softkey.
6. Select the "Gate Settings" menu item.
The R&S Cable Rider ZPH opens a softkey submenu to control the gate settings.
At the same time, the R&S Cable Rider ZPH switches into time domain, as indica-
ted in the display. See
Figure 8-11
(time domain).
7. Select the "Manual SWT" softkey and set the sweep time in a way that the portion
of interest of the signal is visible on the screen.
8. Select the "Gate Delay" softkey.
The R&S Cable Rider ZPH opens an input field to define the trigger delay.
9. Enter the delay time you need.
The measurement now starts after the delay time has passed.
10. Select the "Gate Length" softkey.
The R&S Cable Rider ZPH opens an input field to define the gate length.
11. Enter the length of the gate.
The R&S Cable Rider ZPH now measures over the period of the gate length. After
the gate has closed, the R&S Cable Rider ZPH waits with the measurement until
the next gate signal happens.
The delay time and gate length are represented by vertical blue lines in the dia-
gram area.
12. After setting the gate delay and gate length, exit the gate settings menu with any of
the
function keys
.
The R&S Cable Rider ZPH returns to the frequency domain provided it was active
before setting up the gated trigger. The original span is restored. The R&S Cable
Configuring Spectrum Measurements
