A novel algorithm for detecting the operating state of a calibrated two-port vector network analyzer

A novel algorithm is presented for detecting the operating state of a calibrated two-port vector network analyzer (VNA) which is based on the general 12-term error model. Compared with the Short-Open-Load-Thru (SOLT) calibration method where the 12-term errors must be derived from the nonlinear functions of the actual S-parameters and the measured S-parameters by using an ideal standard kit, the proposed method finds a new way to solve these non-linear equations with just three known of the non-ideal Short-Open-Load (SOL) standards and a zero-length lossless transmission line as the ideal Thru (T) standard. Thus it not only reduces the impact due to the non-ideal standard kit, but also simplifies the complexity of the detecting procedure. The actual S-parameters of a two-port device can be corrected by this new algorithm directly and compared with measurement results by AV3620. The good agreement attests the precision of the new detecting algorithm.