Using our VNA calibration kits with La Techniques VNAs

LA Techniques with Kirkby Microwave calibration kit.

It is absolutely essential that a VNA has the correct calibration constants for a calibration kit. Just taking random opens and shorts, and picking the N calibration kit from your VNA will result in incorrect measurements. They might look fine, and show a nice flat S12 and S21 of close to 0 dB, and an S11 and S22 of -60 dB, but the results of any measurements will be incorrect.

The LA Techniques VNAs only have their own calibration kit data supplied with their software, so the correct constants for the Kirkby Microwave kits must be entered as a user-defined calibration kit.

LA Techniques, like HP, Agilent, Keysight, Copper Moutain and many others represent the fringing capacitance of an open as a 3rd order polynomial:

Cfringing=C0x10-15 + C1x10-27f + C2x10-36f2+C3x10-45f3

where the capacitance is in Farads and the frequency in Hz. However, unlike those manufacturers, LA Techniques consider the offset as being a length in mm, and not a delay in ps. All recently manufacturered Kirkby Microwave calibration kits are supplied with individual data for that kit. This allows higher accuracy than is possible than if generic data for a number of kits is supplied. This information is provide in the file L_A_Techniques-coefficients.txt, included on the USB stick supplied with all kits.

Sample of file L_A_Techniques-coefficients.txt

Here is a sample file, with data in the format used by La Techniques.

Individually measured data on model 85033 S/N 0422 measured to 7000 MHz

Kirkby Microwave can create calibration kit files readable by L A Techniques VNAs. Please let us know the model if you wish us to do this.

** Female short. Short -F- **
Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50.0 ohms
Offset loss: 3000 Mohm/s
Offset delay: 41.159999 ps

** Female open. ** Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50.0 ohms
Offset loss: 3000 Mohm/s
Offset delay: 39.8 ps
C0: 49.061
C1: -94.392
C2: 533.03
C3: -72.379

** Male short. **
Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50.0 ohms
Offset loss: 3000 Mohm/s
Offset delay: 57.970000 ps

** Male open. **
Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50.0 ohms
Offset loss: 3000 Mohm/s
Offset delay: 55.1 ps
C0: 68.637
C1: 627.31
C2: -1541.6
C3: 134.59

** Male-Male thru **
** (NOT needed if VNA supports unknown thru calibration.) **
Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50 ohms
Offset loss: 3000 Mohm/s
Offset delay: 75.972001 ps

** Female-Female thru ** (NOT needed if VNA supports unknown thru calibration.) **
Minimum frequency: 0 MHz
Maximum frequency: 7000 MHz
Offset Zo: 50 ohms
Offset loss: 3000 Mohm/s
Offset delay: 9.361999 ps

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