HP HP 8712ES, User Manual, Page: 265 / 507

ES User’s Guide 6-19
Calibrating for Increased Measurement Accuracy
Calibration Choices
To Perform a Reflection Calibration
For a review of which systematic errors are removed by each type of
reflection calibration, see the descriptions below. These calibrations are
for narrowband-detection measurements only.
For examples of performing a two-port calibration and a one-port
calibration for a reflection measurement, refer to
Chapter 3 .
In general, follow these steps when performing a reflection calibration:
1. Set up the analyzer for your measurement:
• Select or , or
.
• Enter operating parameters other than the default.
2. When performing some user-defined calibrations, you must select a
calibration kit to match the port(s) at your calibration reference
plane. A user two-port calibration requires you to select a calibration
kit for each port. A user one-port calibration requires you to select a
calibration kit for only one port. Refer to
“The Calibration Reference
Plane” on page 6-7 and “Calibration Kits” on page 6-23 .
3. Press , and then one of the following softkeys:
Restoring the default calibration recalls error correction arrays that
were calculated at the factory or during servicing, and then permanently
stored in memory. This one-port calibration was performed using full
band (entire frequency span) and 401 frequency points, and corrects
systematic errors caused by directivity, source match, and frequency
response. It is quick and convenient but not as accurate at narrow
frequency spans. The calibration reference plane is at the analyzer’s
port 1 (S
11
) or port 2 (S
22
), so if you use a cable in your test setup you
should adjust the port extension to match the electrical length of the
cable (see
“Port Extensions” on page 5-18 ). Best accuracy would be
achieved by performing a user-defined one-port calibration. This
calibration is also known as the default calibration.
MEAS 1 MEAS 2
S11 Refl Port 1
S22 Refl Port 2
CAL
Default 1-Port