Shunt-Thru With Series Resistance - Omicron Lab Bode 100 User Manual

Measurement types and applications
Calibration
The Shunt-Thru measurement is basically a Gain measurement that is transformed to an impedance.
Therefore two calibrations are possible. Either a Thru-calibration or an Open, Short, Load calibration.
Thru calibration calibrates the underlying S21 measurement and removes the effect of the cable
connection to the DUT.
Open, Short, Load calibration shifts the reference plane directly to the calibration plane.
For more details on calibrating a Shunt-Thru measurement, please refer to 8.3.4 Calibrating a Shunt-
Thru or Series-Thru measurement on page 84.
Typical applications
A typical application for the Shunt-Thru measurement mode is the ESR measurement of ultra-low ESR
decoupling caps.

7.4.4 Shunt-Thru with series resistance

Shunt-Thru with series resistance is very similar to the normal Shunt-Thru measurement mode. For
more details regarding the normal Shunt-Thru measurement mode, please see 7.2.3 Shunt-Thru on
page 64.
Measurement information
Bode 100 measures S21 gain and calculates impedance Z using the equation:
Compared to the normal Shunt-Thru measurement mode, the series resistors increase the maximum
measurable impedance. This is of advantage when one needs to measure from roughly 10 mΩ to
some kΩs.
The higher the series Resistors Rs are chosen, the higher the maximum recommended impedance is.
However, at the same time the lower impedance limit rises.
OMICRON Lab 65