The S-Parameter calibration type is used to make measurements in the PNA measurement class of Standard S-Parameters such as S11, S12, S21, and S22. In a common 2-Port error correction, this calibration corrects for six parameters in the forward and reverse direction making a total of 12 terms also known as "12 term correction".

Error Correction Corrects a test set for

  • Directivity
  • Source match
  • Reflection tracking
  • Load match
  • Transmission tracking
  • Isolation

The process requires characterized standard terminations which are provided by ATE Systems calibration devices. In calculating the error terms ATE Systems' calibration devices operate in a similar fashion to the E-Cal product line by Keysight.

For more information on error correction see the Keysight Documentation.

The following example shows how to configure a one port standard S-Parameter calibration on port 1 (for an example of more than 1 port see Example03 CAL_SParamWithPower_4Port). In a 1-Port calibration there is a resulting three error terms calculated: directivity, source match, and reflection tracking. Executing this calibration will produce a Cal Set on the PNA labeled "CAL_SParam_1Port" as well as a state file called "After_CAL_SParam_1Port.csa" in the C:\Examples directory of the PC used to run the calibration as well as on the C:\Temp directory of the PNA.

;*******************************************************************************
; Example configuration for a calibration type SParam using 1 port
;*******************************************************************************
[CAL_SParam_1Port]
CalAcquireTimeoutSec = 60
CalSetDescription = Cal Set for CAL_SParam_1Port calibration
CalSetName = CAL_SParam_1Port
CalType = SParam
ConfigType = Calibration
DirectoryToUse = C:\Examples
LoadFilename = Before_CAL_SParam_1Port.csa
PathName = PATH_SParam_1Port
PnaDisplayEnable = 1
SaveFilename = After_CAL_SParam_1Port.csa

; FCM calibration device definition
[FCM_1]
ConfigType = Fcm
ConnectionTimeoutSec = 1.0
FileTransferTimeoutSec = 60
IpAddress = 10.11.0.201
ResponseTimeoutSec = 60

; Path referenced by calibration defining which device will be used
[PATH_SParam_1Port]
ConfigType = Path
PnaPort1Device = FCM_1:1

; PNA definition
[PNA-X]
ConfigType = Pna
ConnectionTimeoutSec = 1.0
DirectoryToUse = C:\Temp
FileTransferTimeoutSec = 60
IpAddress = 10.11.0.200
PortCount = 4
ResponseTimeoutSec = 60
VerifyCommands = 0

The configuration components of this calibration are:

  • The Calibration configuration

The section named [CAL_SParam_1Port] defines the calibration and specifies the name as "CAL_SParam_1Port" along with other parameters. While the example above shows some optional keys which have default values and can be omitted the required keys are:

CalType = SParam
ConfigType = Calibration
DirectoryToUse = C:\Examples
PathName = PATH_SParam_1Port

The important things to note are:

    • The type of calibration performed is specified by the key CalType = SParam
    • This section specifies the Path configuration by name. This path determines which calibration devices will be used.
    • The 'DirectoryToUse' is required here because the 'LoadFilename' and 'SaveFilename' do not have path specifiers in their names and the InCal library requires a location where to find files required to execute the calibration.
  • The Calibration Device (FCM) configuration

The section named [FCM_1] defines an FCM calibration device and specifies the IP address of the device. While the example above shows some optional keys which have default values and can be omitted the required keys are:

ConfigType = Fcm
IpAddress = 10.11.0.201

    • Note that this device is referenced in the Path configuration by its section name 'FCM_1'
  • The Path configuration

The section named [PATH_SParam_1Port] defines the path and specifies the calibration device to be used for each PNA port. While the example above shows some optional keys which have default values and can be omitted the required keys are:

ConfigType = Path
PnaPort1Device = FCM_1:1

    • In this example the path defines only 1 PNA port to be used and the device on that port is FCM_1. The device must also specify the input port used on that device and therefore uses a Device Port Pair (FCM_1:1) as the value rather than just the name.
    • If it is required to control RF switches in order to connect FCM_1 to the PNA port 1 in this example, a SwitchPath will be required to be set. See Example03 CAL_SParamWithPower_4Port for an instance where the SwitchPath is set.  
  • The PNA configuration

The section named [PNA-X] defines the PNA configuration and specifies the values necessary to communicate properly with the PNA. While the example above shows some optional keys which have default values and can be omitted the required keys are:

ConfigType = Pna
DirectoryToUse = C:\Temp
IpAddress = 10.11.0.200

    • In this example while the 'DiectoryToUse' is not technically required it is recommended and sound practice to specify this directory so that intermediary files are stored in a known location on the PNA hard drive.