Multi-port vector neywork analyzer calibration using the 'unknown thru' method

摘要

A multi-pod vector network analyser VNA or a method of calibrating such a VNA comprises performing two-port calibrations on pairs of ports 701 to determine error terms associated with each port. Switch error correction factors are obtained from the two-port calibrations data 702. An "unknown thru" calibration 703 is performed for at least one pair of ports, which are different pairs to those used above during the two-port calibration. The said switch error correction factors are applied to measured data 704 which is then used to determine transmission tracking error terms 705. The transmission tracking error terms for all pairs of ports may be calculated 705, 706 from data produced from the two-port calibrations 701 and the "unknown thru" calibrations 703. The VNA may comprise only one reference receiver and each port may have a different connector type. The two-port calibrations may be performed by an electronic module which steps through a plurality of impedance states.