DOI: 10.1109/TMTT.2024.3399879   IEEEXplore: https://ieeexplore.ieee.org/document/10536177

2 GHz to 1 THz

This is the first time an interlaboratory comparison of measurements of material properties has been conducted over nearly three decades of frequency. Dielectric measurements of seven materials were performed using five different measurement methods across five laboratories, spanning frequencies from 2 GHz to 1 THz.

Contribution of confidence in the accuracy and consistency of material measurements by different laboratories using a variety of techniques.

In general, good agreement in the measurement results was found between the different laboratories and techniques, especially when measurement uncertainties are considered. Doped silicon measurements exhibited strong frequency dependence thought to be due to Drude behavior. Open Resonator (OR) results were performed using both the fixed-frequency equivalent-length method and the variable-frequency fixed-length method and results were in good agreement. Uncertainties in OR results are due primarily to uncertainty of sample thickness for ε′ and uncertainty sources of the VNA itself for tan δ. Free-space (FS) measurements feature uncertainty spikes at the waveguide band edges believed to be due to the transformation of the uncertainties between the time domain and frequency domain after the application of time-domain gating. Material characterization kit (MCK) and time-domain spectroscopy (TDS) measurement uncertainty is related primarily to material thickness and is also influenced by material reinsertion variations. Frequency-domain spectroscopy (FDS) data is heavily affected by periodic oscillations, but their impact can been reduced by using an enhanced algorithm to extract material properties.