New Theoretical Analysis of the LRRM Calibration Technique for Vector Network Analyzers

Abstract—In this paper, a new theoretical analysis of the four-standards line-reflect-reflect-match (LRRM) vector network-ana-lyzer (VNA) calibration technique is presented. As a result, it is shown that the reference-impedance (to which the LRRM calibra-tion is referred) cannot generally be defined whenever nonideal standards are used. Based on this consideration, a new algorithm to determine the on-wafer match standard is proposed that im-proves the LRRM calibration accuracy. Experimental verification of the new theory and algorithm using on-wafer calibrations up to 40 GHz is given. Index Terms—Calibration algorithms, calibration standards, calibration techniques, network-analyzer, on-wafer calibration, reference impedance, self-calibration. I