Investigation of anomalous room temperature conduction losses in normal metals at terahertz frequencies

A number of research groups worldwide have reported discrepancies between loss measurements and classical theoretical predictions for simple millimetre wave and sub-millimetre-wave structures. For the first time, a comprehensive survey of published experimental data for the room temperature surface resistance of normal metals, from DC up to the edge of the mid-infrared frequency range, has been undertaken. It has been found that, with the optical measurements performed within the far-IR region, there does not appear to be an anomalous intrinsic conduction loss phenomenon at room temperature; this is in direct contradiction to the findings of other research groups. This is because the non-optical measurement approaches adopted by Tischer, Schwab et al. and Batt et al. are fundamentally flawed, since anomalous findings could be attributed to one or more of the factors discussed in this paper.