Four-port Asymmetric Calibration Method for Simultaneous Measuring H_x, H_y, and E_z

A four-port composite probe with a pair of symmetric cross-orthogonal loops has been verified to measure electric and magnetic fields simultaneously. But in the near-field measurement, the asymmetry in transmission path is difficult to avoid and will cause the deviations of measurement results. To eliminate the asymmetry effectively, a four-port asymmetric calibration method (ACM) is proposed for simultaneous measuring magnetic and electric fields of H _x , H _y , and E _z . The proposed ACM combines the existing rotate and non-rotate asymmetric calibration methods by using a symmetric calibrator. A four-port probing system is set up for verifying the proposed method, including a six-port vector network analyzer separately connected to four ports of the probe, and a grounded coplanar waveguide (GCPW) as a calibrator. The effectiveness of ACM is well verified by a standing wave induced by an open-terminated GCPW.