An improved planar cavity model for dielectric characterization

Accurate characterization of the dielectric properties of the laminate materials used in printed circuit board fabrication is critical for maximizing the performance of modern high speed circuitry. While many techniques exist for characterizing dielectric materials, most existing techniques are either limited in accuracy or highly impractical for use with planar, copper-clad laminate sheets. A common method involves forming a cavity from the printed circuit board material and calculating the permittivity and dissipation factor from the measured resonant frequencies and quality factor of the cavity. This resonance technique makes the assumption of an ideal cavity, which leads to errors in both measured permittivity and dissipation factor. A more accurate model is proposed that de-embeds the effects of dielectric loss, surface conductivity and reactance, surface roughness, and cavity coupling efficiency. The influence of each of these non-ideal effects on measured dielectric parameters is quantified through mathematical analysis and numerical simulation. Measurements on physical cavities are performed to verify the new model --Abstract, page iii

Snowmass Neutrino Frontier Report

This report summarizes the current status of neutrino physics and the broad and exciting future prospects identified for the Neutrino Frontier as part of the 2021 Snowmass Process