Drude Dispersion in the Transmission Line Modeling of Bulk Absorbers at Sub-mm Wave Frequencies

Drude Dispersion in the Transmission Line Modeling of Bulk Absorbers at Sub-mm Wave Frequencies: A Tool for Absorber Optimization

van Schelven, R.M. (TU Delft Tera-Hertz Sensing)
Fiorellini Bernardis, A. (TU Delft Tera-Hertz Sensing)
Sberna, P.M. (TU Delft EKL Processing)
Neto, A. (TU Delft Tera-Hertz Sensing)

2021

Semiconductor (SC)-based bulk absorbers operating in the (sub-) THz range are discussed. The conductivities of the bulk media are described by the Drude model for electron gas where the electron density is controlled. The Drude model predicts the existence of two frequencies of interest: one associated with the scattering time of the electrons and a second associated with the plasma frequency. The dimensions of the absorbers for a specific frequency range can be minimized by tuning the doping levels. Eventually, the maximum ohmic absorption from a bulk material is achieved when the real part of the characteristic impedance of the absorber is matched to the one of the surrounding medium and the imaginary part of the characteristic impedance is high so that the power entering the material is actually transformed in heat. Using a classic transmission line representation, a matching layer is introduced to further increase the absorption capabilities of an SC slab. Measurements using a time-domain spectroscopy (TDS) system show the increased accuracy of the Drude model

Conductivity
Electric fields
Gold
Ions
Lenses
Metals
Silicon

http://resolver.tudelft.nl/uuid:6806ae2e-b357-42e8-91d3-765f3a799560

https://doi.org/10.1109/MAP.2021.3073092

1045-9243

IEEE Antennas and Propagation Magazine, 64 (2022) (1), 50-60

Institutional Repository

journal article

© 2021 R.M. van Schelven, A. Fiorellini Bernardis, P.M. Sberna, A. Neto