Agilent Technologies 8719D, Руководство пользователя

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TRL and Error-Correction
The standard HP analyzers provide calibration. However, true
calibration is available on instruments equipped with Option 400, Four-Sampler Test
set.
The TRL implementation with Option 400 requires a total of fourteen measurements to
quantify ten unknowns as opposed to only a total of twelve measurements for TRL*. (Both
include the two isolation error terms.)
Because of the four-sampler receiver architecture of Option 400, additional correction of the
source match and load match terms is achieved by measuring the ratio of the two “reference”
receivers during the THRU and LINE steps. These measurements characterize the impedance
of the switch and associated hardware in both the forward and reverse measurement
configurations. They are then used to modify the corresponding source and load match terms
(for both forward and reverse).
The Option 400 configuration with TRL establishes a higher performance calibration method
over TRL* when making measurements, because all significant error terms are
systematically reduced. With the source and load match terms are not corrected, and are
essentially that of the raw, performance of the hardware.
For further information on comparing these two techniques, refer to
Calibration” in Chapter 6.
The following procedures apply to both standard instruments and instruments equipped with
Option 400.
The specific to Option 400 instruments will not contain asterisks
You must have a TRL calibration kit and saved in the as shown in
“Modifying Calibration Kit Standards,” located later in this section.
3. measure the “TRL THRU,” connect the “zero length” transmission line between the two
test
4. To make the necessary four measurements, press:
5.
measure the “TRL SHORT, connect the short to 1, and press:
6.
Connect the short to PORT 2, and press:
7. measure the “TRL LINE,” disconnect the short and connect the TRL line from PORT 1 to
PORT 2.
6-24 Optimizing Measurement Results