This section provides an overview of the calibration commands and when they should be used.

The commands listed in this section work on the first two ports of the instrument on either 2-port or 4-port configurations. The FULL1 calibration is set up with the following calibration commands:

4-port calibrations are more complex and are hence divided into six broad categories:

Under the reflection response calibration type, one can specify up to four individual 1-port response calibrations to be performed using the following command:

For instance, to perform a reflection response calibration on ports 2, 3, and 4, the command is:

The following command is used to define the components used in the reflection calibration:

Available reflection components are: NONE | OPEN | SHORt | OFSH1 | OFSH2 | OFSH3

With a full 1-port calibration type, one can specify up to four individual 1-port calibrations to be performed using the following command:

For instance, to perform a full 1-port calibration on ports 2, 3, and 4, the command is:

Under the transmission response calibration type, one can specify up to six, 2-port combinations:

using three response methods that are stored in a list:

First, clear the list using:

Next, use a combination of the following three commands:

For instance, to specify a forward response calibration on port12, a reverse response calibration on port13, and both forward and reverse calibrations on port14, the commands are:

With a full 2-port calibration type, one can specify two, 2-port calibrations to be performed with six, 2-port combinations:

The port pairs selected must be port exclusive. For instance, if the first calibration is on port23, then the second, if specified, must be on port14. There are 3 calibration types that can be specified:

This is accomplished using one of the commands below for the first calibration:

And one of the following commands below for the second calibration:

For instance, the commands below specify a full, 2-port calibration on port12 and use a one path, 2-port forward calibration as the second calibration:

With a full 3-port calibration type, one can specify a 3-port calibration to be performed on the indicated ports with the following command:

In addition to selecting the ports above, two or three thru lines must be measured using the commands below:

The arguments of the above command are:

For example, to perform a full, 3-port calibration on ports 1, 3, and 4 with thru lines on port pairs 13, 14, and 34, send the following commands:

With a full 4-port calibration type, one can specify a 4-port calibration to be performed on all four ports with the following command:

In addition, three to six thru lines must be measured using the commands below:

Available throughs are:

For example, to perform a full, 4-port calibration with thru lines on port pairs 12, 13, 14, and 24, send the following commands:

The following command sets the connector type:

The connector types are as follows (the second letter is the gender: F for female, M for male, N for no gender):

 

Use the following command to load a calibration kit file with its path and name as string data:

The many calibration standard types are divided into four categories of OPEN, SHORT, LOAD, and THRU (or THROUGH) as described in the following sections.

An OPEN standard has the following parameters that define its electrical behavior:

These coefficients are often displayed in scientific notation as shown below:

If one enters a number for Cx whose magnitude is > 10E-5, then it is assumed that the number must be multiplied by the appropriate power of 10 shown above to determine the coefficient. Otherwise, the coefficient value is taken as is.

The following commands are used to change the OPEN standard parameters:

A SHORT standard has the following parameters that define its electrical behavior:

L0, L1, L2 and L3 are power series coefficients used to calculate inductance as follows:

These coefficients are often displayed in scientific notation as shown below:

If one enters a number for Lx whose magnitude is > 10E-5, then it is assumed that the number must be multiplied by the appropriate power of 10 shown above to determine the coefficient. Otherwise, the coefficient value is taken as is.

There are actually four SHORTS that one may encounter; however, one may be working with more than one at a time so numerics are used to differentiate them as follows:

The following commands are used to change the SHORT standard parameters:

A LOAD standard has the following parameters that define its electrical behavior:

Most calibration kits have two loads; therefore, they are differentiated by naming them LOAD1 and LOAD2. Use the following commands to modify the LOAD parameters:

A THRU (technically a “through”) standard has the following parameters that define its electrical behavior:

Use the following commands to modify the THRU parameters:

Once all of the calibration setup parameters described above have been complete, the actual measurements for the calibration type and methods can be performed. Each calibration type and method requires measuring the appropriate standards using the commands listed below:

Once the measurements are complete, the correction coefficients must be calculated and the calibration corrections must be applied (turned on):

To simulate a calibration, use one of the commands below to specify the calibration type:

The commands below are for simulations with a 4-port test set attached to the VNA:

The following command inputs and outputs the specified correction coefficients:

The correction coefficients must be specified using one of the character data arguments below:

 

The AutoCal calibration method (calibration using a compatible Precision Automatic Calibrator module) must first be specified using the command below:

Then the calibration type is selected using the commands described above in Setting Up a Two-Port Calibration or Setting Up a Four-Port Calibration.

Without a 4-port test set, the calibration types supported are FULL1 and FULL2. With a 4-port test set, the calibration types supported are FULL1, FULL2, and FULL4.

With the exception of the FULL4 calibration, use the commands described above to set the desired calibration type. For a FULL4 calibration, use the calibration type command:

The FULL4 calibration is achieved by performing two FULL2 calibrations on independent port pairs. One to four thru lines must also be measured using the commands listed above in Full Three-Port Calibration.

The following command sets the autocal box orientation manually:

This command inputs a list of up to four comma-separated items:

The following command specifies substituting a true thru line instead of using the thru provided in the autocal box.

The command’s input argument list consists of comma separated data with alternating port selections and on/off flags. For instance, if AutoCals are being performed on Ports 1 and 3 and Ports 2 and 4 with true thrus on the Ports 2 and 4 calibration, then the command is:

Automatic detection of the Autocal module orientation is available with the following command only with 2-Port configurations, but is not offered when a 4-port test set is connected:

Once the AutoCal setup is complete, the following command starts the calibration:

The AutoCal calibration may require interaction with a user to perform some mechanical setup steps such as reversing the autocal box, connecting the autocal box to different port(s), or connecting external thru lines. As each step is completed, send the following command to instruct the VNA to continue with the measurements:

The following is a list of AutoCal return codes:

All VectorStar AutoCal modules support an assurance step. Some Lightning AutoCal modules do not support an assurance step.

The LRL calibration method must first be specified using the command below:

The FULL3 LRL calibration is accomplished by performing two, FULL2 calibrations having a common port. The following command sets the calibration type to a full 3-port LRL calibration for the indicated channel:

The port selection for the CALA calibration is limited to the ports shown below. The command’s argument must complement that of the port selection for the CALB calibration. The port selections available for the CALB calibration are limited based on the port selection made in the CALA calibration as follows:

The FULL4 LRL calibration is accomplished by performing two, FULL2 calibrations on independent port pairs. The following command sets the calibration type to a full 4-port LRL calibration for the indicated channel:

In addition, one to four thru lines must be measured using the commands listed below:

Available throughs are:

The following commands are then used to set up the device parameters:

The following three commands provide backward compatibility with legacy VectorStar software and are used to set up the frequency, line length, and loss values:

The following three commands provide support for newer VectorStar software and are used to set up the frequency, line length, and loss values:

The following commands provide support for newer VectorStar software and for the 4-port test set. Omitting the optional [:CALa] keyword in these commands provide support for legacy 2-port instruments:

 

The following commands are used for the corresponding CALB parameters:

 

The following command defines which match corresponds to which port:

 

The following commands collect LRL calibration data: