Keysight Technologies E5400-Pro Series, User Manual

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46 Keysight Technologies E5400-Pro Series Soft Touch Connectorless Probes User’s Guide
3 Operating the E5404A-Pro Series Probes
Equivalent Probe Loads
The following probe load models are based on in-circuit measurements
made with a Keysight 8753E 6 GHz network analyzer and a Keysight
54750A TDR/TDT using a 50
Ω
test fixture. The following schematic
accurately models the probe load out to 6 GHz. The figure on the following
page shows the agreement between measured impedance and this model.
Figure 21 Probe load models (E5404A)
400
Ω
Rtap
Cstub
0.375pF
Rtip
100k Ω
Din
Ctip
10pF
250
Ω
Rtip1
1.17nH
Lspring2
0.63nH
Lspring1
Cstub
0.375pF
Rgnd1
10
Ω
Ccoupling
0.070pF
Rtip2
100k
Ω
Din
Ctip
10pF
Rgnd2
120
Ω
Complex
(Includes capacitive coupling between channels and inductance of spring pins.)
Simple
(Does not include capacitive coupling between channels or inductance of the spring pins)