A Broadband, Via-Less, and Reusable Characterization Method for Advanced Packaging Materials with Multimode Gap Waveguide Resonator

A broadband, via-less, and reusable multimode resonant complex permittivity measurement method for advanced packaging materials based on gap waveguide is presented in this paper. By feeding energy from a standard rectangular waveguide of W-band through a coupling slot at both ends of a gap waveguide resonator, the quasi-TE10k mode is excited at different frequencies inside the resonator. The gap waveguide resonator is properly designed for operating frequency and multimode measurement. And the complex permittivity can be extracted from the resonant frequency and quality factor of the resonator. The calibration for electromagnetic band gap (EBG) leakage, metal loss, and processing errors can also be achieved by measuring the Sparameter of the resonator without the dielectric film. An example of 100 um thick polyimide (PI) characterization is given.