System Overview
R&S
®
CMW500
59
User Manual 1173.9463.02 ─ 02
independent attenuating component in the test setup (e.g. a non-ideal cable, a test fixture
or an RF shielding chamber used to hold the DUT), or an amplifier.
Additional settings for compensation of a frequency-dependent attenuation/gain are pro-
vided by the base system of the instrument. They allow to define correction tables con-
taining pairs of frequencies and associated attenuation/gain values.
If a table is activated for an output connector, the correction value associated with the
current carrier frequency and the frequency-independent "External Attenuation" defined
in the generator settings are added. Correction values for intermediate frequencies
between two frequency entries are calculated using linear interpolation. For frequencies
higher than the highest frequency entry in the table, or lower than the lowest frequency
entry, the correction value associated with the highest / lowest frequency entry is used.
With a total external attenuation of x dB, the generator power is increased by x dB so that
the actual generator power differs from the output power shown in the dialog. The output
power in the dialog is available at the input of the DUT. Negative values of the external
attenuation decrease the effective generator power.
Frequency-independent attenuations are defined as part of the generator settings, refer
to the description of the generator application. Frequency-dependent correction tables
are administrated and activated/deactivated only via remote commands
(
...:FDCorrection:...
).
While a correction table is active for the connector currently used by an application, the
GUI of the application displays the table name together with the frequency-independent
attenuation setting.
The table entries can be displayed by clicking the button "FDCorr!".
4.2.3 Real-Time and Arbitrary (ARB) Generators
The properties of real-time generator signals are based on the settings in the generator
configuration dialogs. An example for a real-time signal (dual-tone GPRF signal) is
described in section
chapter 3.2.1, "Generating an RF Signal"
the arbitrary (ARB) generator signal is based on a "waveform file" (typically, a file gen-
erated with R&S WinIQSIM) which is loaded and processed at runtime. For details refer
to the "GPRF Generator" description.
The R&S CMW500 provides real-time and ARB generator signals for many network
standards. Both generator types have their specific advantages.
Generators
