Wide-Bandwidth Coaxial PWB Transmission Line Probe

The design, fabrication, and test of a wide-bandwidth (3-dB attenuation bandwidth ges 30 GHz), 50 Omega, passive coaxial probe for the electrical characterization of printed wiring board (PWB) transmission lines is described. The probe can make thousands of repeated contacts, using spring-loaded interconnects, without affecting probe performance. The probe contains an internal mechanism for dissipating static charge on the signal line of the PWB transmission line and is long enough (approximately 10 cm) to act as a transfer standard for characteristic impedance testing, as per the time-domain reflectometry test method described in IPC TM 2.5.5.7.