96                                       Keysight N9938-90003 User’s Guide
Calibration for NA, CAT, and VVM Modes
—Press Start Calibration. When prompted, verify the ECal module 
connection, then press Measure. The standards within the ECal module are 
automatically connected and measured.
Simple Response Cals 
Simple Response Cals are used to quickly calibrate the magnitude and phase 
of a measurement using any Open, Short, or Thru component. These may be 
calibration standards, but because a Cal Kit is not selected, they are not 
modeled. Measurement accuracy is generally low. Use a Simple Response Cal 
to make quick measurements when using a jumper cable to connect the DUT 
to the FieldFox. Otherwise, CalReady is usually more accurate.
When prompted, choose a standard based on the displayed measurements to 
be calibrated. For example, to calibrate S11, connect either an OPEN or 
SHORT to the port 1 reference plane. 
When Simple Response Cals are performed, the source match and reflection 
tracking terms from CalReady are updated by the measured Short or Open that 
is used during the calibration. 
1-port response cals are also available from the Mechanical Cal menu. Learn 
more in “Calibration Type” on page 98.
Normalize uses a THRU standard or cable between port 1 and port 2 to cal an 
S21 and S12 Transmission measurement (NA Mode) and a 2-port Insertion 
Loss measurement (CAT Mode). In VVM Mode, this is performed using Zero.
When a Normalization is performed, the forward and reverse transmission 
tracking terms from CalReady are updated to account for the THRU that is 
used during the normalization process.
How to perform a Simple Response Cal
— Select the measurements to be calibrated. See the relevant Mode (NA, CAT, 
or VVM) for measurement selections.
’Unknown THRU’: When prompted: “Connect port 1 to port 2", then 
connect port and port 2, using a coaxial cable or an appropriate thru 
adapter. Do NOT use the internal ECal THRU, because the ECal thru 
calibration model is incorrect for this calibration type.  
 
‘Flush THRU’: When prompted: “Connect port 1 directly to port 2", then 
you must connect the ports directly together at the calibration reference 
plane with no adapter or other cabling.  
 
Learn more in “Calibration Type” on page 98.
You can perform a Simple Response Cal for either: S11, or S22, or S21 AND 
S12.