R&S ESU Series, Руководство по эксплуатации, Страница: 299 / 855

R&S ESU Instrument Functions
Basic Settings
4.268 Operating Manual 1302.6163.12 - 03
PREAMP The PREAMP softkey opens the preamplifier submenu
PREAMP ON/
OFF The PREAMP ON/OFF softkey switches the preamplifier on or off.
The softkey is available only in the analyzer mode when the measurement with pre-
selection is activated.
Remote command:
:INP:GAIN:STAT ON | OFF
LN PREAMP
ON OFF The LN PREAMP ON/OFF softkey switches the low noise preamplifier (100 kHz to
upper frequency limit of the instrument) on and off. The softkey is only available with
option R&S ESU-B24. As of firmware version 4.43, it is possible to activate the low
noise preamplifier in combination with an active preselector.
Note that since the low noise preamplifier is in front of the preselection filters, the
risk of intermodulation products increases.
Default value is OFF. Activating the low noise preamplifier automatically turns off the
standard preamplifier.
Remote command:
:INP:GAIN:LNA:STAT ON | OFF
4.9.3.4 Transducer
A transducer is often connected ahead of R&S ESU both during the measurement of
useful signals and EMI and converts the useful or interference variable such as field
strength, current or RFI voltage into a voltage across 50 Ohm.
Transducers such as antennas, probes or current probes mostly have a frequency-
dependent transducer factor which can be stored in R&S ESU and automatically
has the correct unit during level measurement.
If a transducer is switched on it is considered as part of the unit during the measure-
ment, i.e. the measured values are displayed in the correct unit and magnitude.
When working with two measurement windows, the transducer is always assigned
to two windows.
R&S ESU distinguishes between transducer factor and transducer set . A trans-
ducer factor takes the frequency response of a single transfer element, e.g. an
antenna into consideration. A transducer set can summarize different transducer
factors in several subranges (several transducer factors at the same time), e.g. an
antenna, a cable and a diplexer.
A transducer factor consists of max. 50 reference values defined with frequency,
transducer factor and the unit. For the measurement between frequency values lin-
ear or logarithmic interpolation of the transducer factor can be chosen.
Several factors can be compiled in a transducer set provided that all factors have
the same unit or unit "dB". The frequency range covered by a set can be subdivided
into max. 10 subranges (each with up to 4 transducer factors) which follow each
other without a gap, i.e. the stop frequency of a subrange is the start frequency of
the next subrange.
The transducer factors used in a subrange have to fully cover the subrange.
The definition of a transducer set is recommended if different transducers are used
in the frequency range to be measured or if a cable attenuation or an amplifier has
to be taken into consideration.
If a transducer set is defined during a frequency sweep, the latter can be stopped at
the interface between two transducer ranges and the user is asked to exchange the
transducer.