Characterization of Printed Circuit Board Materials Using Multiple Transmission Lines With Probing Techniques Up to 110 GHz

摘要

This paper presents the characterization method and extracted results of printed circuit board (PCB) material, in dielectric constant (DK) and dissipation factor (DF), by using scattering parameter (S-parameter) measurements of multiple transmission lines (TLs) with probing techniques. The probe parasitics with the associated cables/connectors effects and non-ideal features of the measurement equipment are fully removed with the aids of mathematical treatments for the measured raw data without prior calibration. The multiple TLs are designed to overcome the frequency limitation, where the TL phase shift crossing 180-degree may yield the solution changes dramatically due to small measurement uncertainties. The desired DK and DF then are evaluated from the measured transmission line propagation constant with properly cancellation of the conductor losses. This broadband DK/DF extraction approach is additionally compared to the conventional straight-line resonator method, and discussions of the error sources are addressed as well. Experiments on the NF30 substrate in stripline structure are shown from 1 GHz to 110 GHz, based on the measurement systems including the Anritsu M7838E network analyzer and the EverBeing probe station with GGB on-wafer probes.