Ultra-Wideband Complex Permittivity Extraction of IC Packaging Materials beyond 100 GHz

In this work a simple but yet precise permittivity measurement concept is proposed that is especially suited for broadband characterization of IC packaging material beyond 100 GHz. The novel concept is based on the evaluation of the propagation coefficient of the TE10-mode of a rectangular waveguide with the use of an advanced analytic transmission line model. To eliminate parasitic conductor effects as the bulk conductivity and surface roughness of the waveguide walls, two measurements are carried out: One measurement with an air-filled waveguide and one measurement where the waveguide is filled with the material under test. With these two measurements and by applying the analytic transmission line model, the parasitic distortions can be eliminated. The approach enables ultra-wideband permittivity determination and is not limited to a specific frequency range. The complex permittivity of an investigated packaging material could almost continuously be extracted from 110 GHz up to 320 GHz. The method is experimentally verified on the basis of material samples with material parameters given in literature.