Characterization of cross-line up to 110 GHz using two-port measurements

Cross-line, a four-port device, used for capacitive cross coupling in differential millimeter-wave amplifiers is modeled and characterized up to 110 GHz using two-port vector network analyzer measurement results. This passive component is electrically symmetrical to be used in differential amplifiers for decreased amplitude and phase mismatch. Two characterization structures are used for the method to be applied. The results are compared with four-port measurements up to 67 GHz. The comparisons show good agreement between the two methods.