Investigation of Wang's model for room-temperature conduction losses in normal metals at terahertz frequencies

Evaluating Surface Impedance Models for Terahertz Frequencies at Room Temperature

“…It is evident that the expression for intrinsic bulk conductivity, quoted by both Harrison and Wang, is derived for longitudinal wave propagation [2]. As a result, his model has no meaning for surface impedance and excess conduction loss calculations (as they are based on transverse wave propagation for normal incidence).…”

“…With spatial charge-density fluctuations being attributed to lamina-type sheets of conduction currents, as an analogy to a periodic lattice of fixed positive ions, Wang adopted Harrison's screening potential theory. To this end, Harrison's semiclassical expression for intrinsic bulk conductivity, σ H , was used to calculate Wang's surface impedance, Z SW [2]:…”

“…It was poorly assumed that with such long wavelengths of potential there is no difference between conductivities for transverse and longitudinal fields in cubic materials [5]. Wang then applied his spatial dispersion theory of excess conduction loss to room temperature measurements of copper, from DC up to 6.7 THz, using the measured data at 35 GHz and 70 GHz reported by Tischer [1,2].…”

“…It was found that the classical relaxation-effect model was still valid up to these frequencies. In another study, an elaborate semiclassical model to describe anomalous excess conduction losses at room temperature was found to be completely erroneous [2]. In order to create accurate analytical models, it is important to develop semiclassical modeling strategies [3] or develop quantum mechanical treatments.…”

THz Applications for the Engineering Approach to Modelling Frequency Dispersion within Normal Metals at Room Temperature

“…Indeed, the robustness of this model has been tested in recent years for normal metals at room temperature from dc to terahertz frequencies [1][2][3][4]. For example, it has been used to validate measurements [1], alternative frequency dispersion models [2,3] and commercial electromagnetic simulation software [4]. However, when compared to the over-simplified classical skin-effect model (with associated variables indicated by the suffix "o"), the classical relaxationeffect modelling approach (with associated variables indicated by the suffix "R") for THz structures at room temperature can be mathematically cumbersome and not insightful.…”