
ET User’s Guide
3-63
Making Measurements
Measuring Impedance Magnitude
Measuring Impedance Magnitude
The impedance (Z) of a DUT can be calculated from the measured
reflection or transmission coefficient. The impedance magnitude format
allows measurement of impedance versus frequency or power. This
measurement can be useful for many types of devices, including
resonators and discrete passive components.
The analyzer measures the reflection or transmission response of the
DUT, converts it to the equivalent complex impedance, and displays the
magnitude. Two simple conversions are available, depending on the
measurement configuration.
An accurate impedance measurement is highly dependent on a good
calibration. The accuracy of the impedance measurement is best when
the measurement results are near the analyzer's system impedance (50
or 75 ohms). The resolution is limited (by internal math calculations) to
approximately 5 to 10 milliohms.
To use the impedance magnitude format, press
.
How the Reflection Measurement Works
A reflection trace can be converted to equivalent impedance using the
model and equations shown in
Figure 3-32, “Impedance Calculation for
In the formula shown in
Γ
is the
complex reflection coefficient. The complex impedance, Z
Refl
, is computed
based on
Γ
and Z
0
. The analyzer displays the magnitude of Z
Refl
. This
measurement assumes a two-terminal device, connected between the
analyzer's REFLECTION RF OUT port and TRANSMISSION RF IN
port.
FORMAT
More Format Impedance Magnitude
Summary of Contents for HP 8712ET
Page 8: ...viii ET User s Guide ...
Page 17: ...ET User s Guide 1 1 1 Installing the Analyzer ...
Page 34: ...1 18 ET User s Guide Installing the Analyzer Preventive Maintenance ...
Page 35: ...ET User s Guide 2 1 2 Getting Started ...
Page 52: ...2 18 ET User s Guide Getting Started Performing the Operator s Check ...
Page 53: ...ET User s Guide 3 1 3 Making Measurements ...
Page 118: ...3 66 ET User s Guide Making Measurements Measuring Impedance Magnitude ...
Page 119: ...ET User s Guide 4 1 4 Using Instrument Functions ...
Page 143: ...ET User s Guide 4 25 Using Instrument Functions Using Markers Figure 4 15 Delta Marker Mode ...
Page 149: ...ET User s Guide 4 31 Using Instrument Functions Using Limit Testing Figure 4 16 Limit Lines ...
Page 207: ...ET User s Guide 5 1 5 Optimizing Measurements ...
Page 226: ...5 20 ET User s Guide Optimizing Measurements Measuring Devices with Long Electrical Delay ...
Page 227: ...ET User s Guide 6 1 6 Calibrating for Increased Measurement Accuracy ...
Page 266: ...6 40 ET User s Guide Calibrating for Increased Measurement Accuracy Checking the Calibration ...
Page 267: ...ET User s Guide 7 1 7 Front Rear Panel ...
Page 292: ...7 26 ET User s Guide Front Rear Panel Line Module ...
Page 293: ...ET User s Guide 8 1 8 Hardkey Softkey Reference ...
Page 395: ...ET User s Guide 9 1 9 Specifications ...
Page 397: ...ET User s Guide 9 3 Specifications System Performance ...
Page 443: ...ET User s Guide 10 1 10 Safety and Regulatory Information ...
Page 449: ...ET User s Guide 10 7 Safety and Regulatory Information Regulatory Information ...
Page 450: ...10 8 ET User s Guide Safety and Regulatory Information Regulatory Information ...
Page 451: ...ET User s Guide 11 1 11 Factory Preset State and Memory Allocation ...