
6-20
ET User’s Guide
Calibrating for Increased Measurement Accuracy
Calibration Kits
For all four standard types, the Z
0
(characteristic impedance), Delay,
and Loss must be set. For an open, C
0
, C
1
, C
2
, and C
3
, the capacitive
model parameters, must also be set.
NOTE
When creating a user-defined calibration kit, if a standard is not defined,
the currently defined values for that standard will be retained. The best
practice is to define all of your standards and characteristics when
creating a user-defined calibration kit.
Z
0
Z
0
is usually set to the system characteristic impedance
(usually either 50 or 75 ohms).
Delay
Delay is equivalent to a uniform length of transmission
line between the standard being defined and the actual
measurement plane. For an open, short, and load, the
DELAY is entered as the one-way travel time from the
measurement plane to the standard in seconds. For a
through, the DELAY is entered as the one-way travel
time between the measurement planes in seconds.
Delay can be measured or determined from the precise
physical length of the standard, divided by the velocity
factor.
Loss
Loss is used to specify energy loss, due to skin effect,
along a one-way length of coaxial delay. The value of
loss is entered as ohms/second at 1 GHz. For many
applications, the loss value can be set to zero without
noticeable degradation. To compute the loss of your
device, measure the delay in seconds and the loss in dB
at 1 GHz. Then, compute:
C
0
, C
1
, C
2
, C
3
At high frequencies, an open rarely has perfect
reflection characteristics because fringing capacitance
causes phase shift that varies with frequency.
Loss
Ω
s
----
dB loss
Z
0
Ω
( )
×
4.3429
delay s
( )
×
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=
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 ...