Proceedings of SPIE - the International Society for Optical Engineering
We demonstrate the first long wave infrared (LWIR) transmission line design and characterization. Two of the widely used transmission-lines: coplanar striplines (CPS) and microstrip (MS) lines are characterized at IR frequency (28.3THz), in terms of transmission line parameters: characteristic impedance (Z₀, attenuation constant (α) and effective index of refraction (nᵉᶠᶠ), through modeling, fabrication and measurement. These transmission-line parameters cannot be directly measured, what can be measured is the antenna response. So we compute, measure and compare the response of the dipole antenna connected to these transmission lines as a function of transmission-line length. The response depends on the transformation of antenna impedance along the transmission-line length according to the transmission-line parameters (Z₀, α and nᵉᶠᶠ) of the line. Comparison of measured and computed response validates extracted transmission-line parameters. This paper demonstrates excellent agreement between measured and computed response for both types of transmission-lines under study.
Mandviwala, T. A., López-Alonso, J. M., Lail, B. A., & Boreman, G. D. (2006). Characterization of transmission lines at IR. Paper presented at the Proceedings of SPIE - the International Society for Optical Engineering, 6212 doi:10.1117/12.666066