Determine the coefficient of the standard OPEN

Question

How can one determine the coefficient of the standard OPEN?

Answer

With a ZVR or a ZVC it is possible to determine the coefficient of the standard OPEN. You need the conversion program and have to read the README attached to this program.

Please proceed as follows:

• One has to know the length of the THROUGH and to enter it into the ZVR/C
• Calibrate the ZVR/C with TRM. Calibration has to be performed at the right reference plane (male or female)
• Set the ZVR/C to phase measurement
• Connect the OPEN to the ZVR/C and then check the phase. It has to be a line. If the phase is not a straight line, the length of the THROUGH is not correct.
• Set 8 markers and distribute them evenly on the screen, at a spacing of 500 MHz for the ZVR and 1 GHz for the ZVC
• Note the 8 phase values and write them into a file, for example C0.DAT
• Adapt the other parameters (frequency...) as described in the README file
• Run the program C.EXE
• The result is now in C0.CN
• Enter the fringing capacitances into the ZVR/C

The values created can be checked using the following methods:

- Make a TOM calibration. If you get no error messages, it seems to be all right

- Connect an air line to port 1 and a SHORT to the air line. Check S11 and the amplitude is the error. It should be around 0 dB.