Rohde & Schwarz FPL1000 Series, User Manual

Page: 255 / 899

The Spectrum Application (RF Measurements)
R&S
®
FPL1000
255 User Manual 1178.3370.02 ─ 03
Result Summary
Result summaries provide the results of specific measurement functions in a table for
numerical evaluation. The contents of the result summary vary depending on the
selected measurement function. See the description of the individual measurement
functions for details.
Remote command:
LAY:ADD? '1',RIGH, RSUM
, see
LAYout:ADD[:WINDow]?
on page 632
Spectrogram
A spectrogram shows how the spectral density of a signal varies over time. The x-axis
shows the frequency or sweep time, the y-axis shows the measurement time. A third
dimension, the power level, is indicated by different colors. Thus you can see how the
strength of the signal varies over time for different frequencies.
The spectrogram display consists of two diagrams: the standard spectrum result dis-
play (upper diagram) and the spectrogram result display (lower diagram).
For details see Chapter 7.10.2.1, "Working with Spectrograms" , on page 471.
Remote command:
LAY:ADD? '1',RIGH, SGR
, see
LAYout:ADD[:WINDow]?
on page 632
7.2.3 Channel Power and Adjacent-Channel Power (ACLR) Measurement
Measuring the power in channels adjacent to the carrier or transmission channel is
useful to detect interference. The results are displayed as a bar chart for the individual
channels.
● About Channel Power Measurements .................................................................. 255
● Channel Power Results .........................................................................................256
● Channel Power Basics ..........................................................................................258
● Channel Power Configuration ............................................................................... 262
● How to Perform Channel Power Measurements ...................................................270
● Measurement Examples ....................................................................................... 273
● Optimizing and Troubleshooting the Measurement .............................................. 276
● Reference: Predefined CP/ACLR Standards ........................................................ 277
7.2.3.1 About Channel Power Measurements
Measuring channel power and adjacent channel power is one of the most important
tasks during signal analysis with the necessary test routines in the field of digital trans-
mission. Theoretically, a power meter could be used to measure channel power at
highest accuracy. However, its low selectivity means that it is not suitable for measur-
ing adjacent channel power as an absolute value or relative to the transmit channel
power. Only a selective power meter can measure the power in the adjacent channels.
Measurements and Results