Rohde & Schwarz 1309.6000.08 - Measuring with Transducer Factors

R&S FSH Measuring with Transducer Factors
1309.6275.12 4.83 E-2
Measuring with Transducer Factors
The frequency-dependent transducer factor of transducers and antennas can be directly considered in
the measurement result. A transducer factor consists of a numeric values and a unit. The R&S FSH
corrects the level values of the trace by the values of the transducer. At the same time, the unit of the
transducer is assigned to the level axis. When field-strength measurements are performed with the aid
of antennas, for instance, the electrical field strength is directly indicated in dBKV/m on the R&S FSH. A
transducer factor can also be used to correct a frequency-dependent attenuation, e.g. of a cable
between DUT and RF input of the R&S FSH.
More than 100 transducer factors with 60 reference values each can be stored internally. The maximum
number of transducer factors may be reduced if cable models, channel tables, limit lines, or data sets
are stored simultaneously (see "Saving and Loading Instrument Settings and Measurement Results" in
this chapter).
Interpolation between the values is performed with the aid of a modified spline algorithm. Even if only
relatively few values such as maxima, minima and turning points are available, this algorithm can easily
simulate the correction factors of common transducers. Two transducers can be switched on at a time.
The second transducer must be assigned the unit dB. The R&S FSH adds the two transducers to a total
transducer.
Transducer factors are defined with the aid of control software FSH4View. They are transferred from
the PC to the instrument via LAN or the USB interface.
Units supported for transducer factors:
- dB
- dBKV/m
- dBKA/m
- W/m
2
The unit dB does not change the unit set on the R&S FSH. It can be used, for instance, to compensate
for frequency-dependent loss and gain at the input of the R&S FSH. The units dBKV/m and dBKA/m
convert the output power of an antenna into electric or magnetic field strength. The unit W/m
2
is used to
calculate and display the power flux density.
For example, to compensate for the cable loss between the transducer and the RF input, the R&S FSH
can use two transducers at the same time. One of them must have the unit dB, however, i.e. it must
correspond to one loss or gain value.