Specifications

Setting and Using the Measurement Functions R&S FSH
1145.5973.12 4.84 E-10
Taking additional attenuation into account
When the directional power sensor is connected to a test point not directly but via a cable, the influence
of cable attenuation can be taken into account. For this purpose, the cable attenuation for the
measurement frequency in question is to be entered, i.e. as a positive dB value if the power and
matching are to be measured at the source and the cable is connected between the source and the
power sensor, and as a negative dB value if the power and matching are to be measured at the load
and the cable is connected between the load and the power sensor. The directional power sensor then
corrects the power and matching values to produce the results that would have been obtained if it had
been directly connected to the test point.
¾ Press the AMPT key.
¾ Press the REF OFFSET softkey.
The value entry box for the reference offset opens.
¾ Enter the desired offset using the rotary knob, the
cursor keys or the number keys and confirm the
entry with the ENTER key.
The selected offset is displayed in the middle at the top
of the screen and is taken into account in the power
(level) and matching results.
If high powers are applied that exceed the maximum input level of the R&S FSH-Z14 or R&S FSH-Z44,
a directional coupler or an attenuator has to be connected ahead of the power sensor. In such cases,
the coupling attenuation of the directional coupler or the attenuation value of the attenuator are to be
entered as positive dB values (see above) into the R&S FSH to ensure true measured power readout.
In both cases, a termination or an attenuator of sufficient power-handling capacity has to be connected
to the power sensor at the load end. The matching readout is irrelevant in such case since it is likewise
corrected by taking into account the attenuation value of the termination or attenuator (see
measurement via cable).