Experimental Characterization of End-Launched Connectors Used in Printed Circuit Boards with Multiline Thru-Reflect-Line Calibration Technique

The complete two-port scattering parameters (S-parameters) of end-launched connectors used in printed circuit boards (PCBs) are experimentally characterized in this paper, by using multiline thru-reflect-line (MTRL) calibration technique. First, the network analyzer is calibrated to the test cable ends in coaxial connectors by commercial coaxial calibration kit using short-open-load-thru (SOLT) standards. Second, the MTRL calibration items with the end-launched connectors including several transmission lines (TLs) in different lengths and a short/open reflect test item are measured to perform the additional calibration to change the reference planes to the PCB TL ends. In the third step, the measured reference planes are further shifted to the edges of the PCBs by simply inserting a complex phase term constituted by the planar TL propagation constant, which is the by-product of the MTRL calibration. Fourth, the characteristic impedance of the PCB TL is resolved by using an additional resistor test item under low substrate loss condition, for transforming the reference impedance to the normal 50Ω. Finally in the fifth step, the solved error box terms after MTRL calibration are transformed to the reference impedance of 50 Ω to construct the complete two-port S-parameters of the two end-launched connectors at port-1 and port-2, simultaneously. For the experiment, the conductor-backed coplanar waveguide (CB-CPW) with RO-4003 substrate is used for the PCB TL in this study, and the end-launched K-connectors in male and female are tested, respectively, in the frequency range from 0.5 GHz to 40 GHz.