Accuracy Of Electronic Calibration Versus Mechanical Calibration - Keysight Technologies 85091D Reference Manual

General Information
Manual Overview
— A female connector gage has a male interface so it can measure female

Accuracy of Electronic Calibration versus Mechanical Calibration

N755xA ECals can be used for S-parameter measurement calibrations. The
residual measurement uncertainty makes them unsuitable for advanced
applications, such as load pull, noise figure, etcetera.
As the number of DUT test ports increases, the required number of calibration
measurements also increases. This boosts the probability of bad connections
and bad calibrations when mechanical calibration standards are used rather
than ECal. Also, test port cable repeatability and stability errors are amplified
by the increased number of connections and disconnections. To perform an
SOLT 4-port calibration, a minimum of twelve 1-port standards and three
2-port (thru) standards are measured, requiring a total of eighteen
connections. The same calibration using a 2-port ECal module (N755xA and
N469xD) requires only four connections.
Ignoring connection related errors, the following table compares the accuracy
of ECal versus mechanical calibration in various calibration options.
Mechanical Calibration Type
1-Port, calibration constant (not
data-based) SOL
1-Port, short, open, sliding load
1-Port, data-based, expanded
2-Port TRL
≥2-Port, calibration constant SOL, flush
a
thru
≥2-Port, calibration constant SOL,
unknown thru
1-2
devices.
ECal Thru Type
NA
NA
NA
All types
Characterized
Internal unknown
External flush
Characterized
Internal unknown
Measurement
Reflection
Reflection
Reflection
Reflection
Transmission
Reflection
Transmission
Reflection
Transmission
Reflection
a
Transmission
Reflection
Transmission
Reflection
Transmission
Electronic Calibration Modules Reference Guide
ECal Mechanical
Calibration
++
+
+
++
++
++ ++
++
++
++ ++
++ =
=