Calibrating for Noninsertable Devices

A test device having the same sex connector on both the input and output cannot be connected directly into a transmission test configuration. Therefore, the device is considered to be rwninsertuble, and one of the following calibration methods must be performed.

For information on performing measurement calibrations, refer to Chapter 5, “Optimizing Measurement Results n

Adapter Removal

The adapter removal technique provides a means to accurately measure the noninsertable device. For each port, a separate 2-port error correction needs to be performed to create a calibration set. The adapter removal algorithm uses the resultant data from the two calibration sets and the nominal electrical length of the adapter to compute the adapters actual S-parameters. This data is then used to generate a separate third cal set in which the forward and reverse match and tracking terms are as if Port 1 and Port 2 could be connected. This is possible because the actual S-parameters of the adapter are measured with great accuracy, thus allowing the effects of the adapter to be completely removed when the third cal set is generated. See Chapter 5.

Matched Adapters

With this method, you use two precision matched adapters which are “equal.” To be equal, the adapters must have the same match, ZO, insertion loss, and electrical delay.

Modify the Cal Kit Thru Definition

With this method it is only necessary to use one adapter. The calibration kit thru definition is modified to compensate for the adapter and then saved as a user kit. However, the electrical delay of the adapter must hrst be found. The adapter match will degrade the effective load match terms on both ports as well as degrade the transmission frequency response (tracking).

Application and Operation Concepts 6-l 08

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HP 8753E manual Matched Adapters, Modify the Cal Kit Thru Definition