LRM and LRRM Calibrations with Automatic Determination of Load Inductance

Two new techniques are presented in an effort to achieve greater accuracy and better repeatability in the on-wafer calibration of vector network analyzers. The first is a method of determining an inductance value for the match standard during the calibration process so that only its resistance, not its reactance, needs to be known. The second is a new type of calibration, LRRM (line-reflect-reflect-match), which is a variation of LRM with several possible advantages. Also, a simple series resistance-inductance model for a coplanar load is experimentally investigated to 40 GHz and found to provide a good description of the load behavior.