7-9 MERGE CAL FILES
APPLICATION The Merge Cal Files application allows the user to combine two or
more calibrations that were performed on the VNA, but having differ-
ing frequency ranges. This is of particular importance when a wide
band RF calibration cannot be performed because wide band calibra-
tion components, such as loads and shorts, are not available. Such a
case exists when using Anritsu’s 37x97E wideband VNAs. Here, the
preferred calibration method would be to perform a standard method
(SOLT) coaxial calibration in the 0.04 to 65 GHz bands, a triple off-
set-short (SSST) coaxial calibration in the 65 to 110 GHz band, then
combine the calibrations to yield a wideband 0.04 to 110 GHz calibra-
tion that can be saved and recalled.
The resultant calibration file setup will be the first calibration file
setup except that the frequency points and RF correction values of the
second calibration file will be intermingled with the frequency points
and RF correction values of the first.The start and stop frequencies
will be adjusted to reflect the lowest and highest frequencies in the in-
termingling. If there are frequency points in common, then the correc-
tion values of the first file will be used and that frequency and data
point in the second file will be discarded.
Both RF calibration files must be the same type, that is, full 12 Term,
1 Path 2 Port Forward, 1 Path 2 Port Reverse, etc., and the total num-
ber of frequency points of the first and second files added together can-
not exceed 1601.
In most cases, it doesn’t matter which calibration file is chosen as the
first calibration file; however, if the VNA is a 37397E used in a Broad-
band setup that crosses the 65 GHz switchpoint, it is advised that the
first calibration data be from the lower frequency band and the second
calibration data be from the higher frequency band. Additionally, if the
higher frequency band calibration starts at 65.0 GHz, the lower fre-
quency band calibration must end at 65.0 GHz. This will prevent a
spike at the 65.0 GHz band switch point.
NOTE
Refer to Appendix A, Front Panel Menus, for descriptions
of menus MRG1, EXT_MRG1, MRG2, and MRG3 that re-
late to this application.