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R&S
RT-ZZ80
Application range of transmission line probes
Use the R&S RT-ZZ80 only for measurements of low-impedance sources,
preferably in 50 Ω or 75 Ω impedance controlled environments.
The advantage of transmission line probes is the nearly constant input impedance
over the frequency range, even at very high frequencies. Thus, transmission line
probes are qualified also for measurements of very broadband signals, which
cannot be measured using traditional passive probes.
4.2.2
Input Impedance
The input signal loading caused by the probe is determined by its input impe-
dance Z
. The
figure 4-1
in
Z
consists of the following probe-specific parameters.
in
● Input resistance R
● Input capacitance C
● Minimum input impedance |Z
The resulting input impedance versus frequency is indicated in
trace shows three characteristic areas that can be assigned to R
The resulting loading of a step signal at the input of the probe is given in
ure
4-8.
The connection inductance L
is therefore not taken into account in the following.
User Manual 1409.7689.02 ─ 02
presents an equivalent circuit model.
in
in
|
min
has only a minor effect on the signal loading and
con
Measurement Principles
Signal Loading of the Input Signal
figure
4-7. The
, C
, and |Z
|.
in
in
min
fig-
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