Precision Dielectric Measurements of Nonpolar Polymers in the Millimeter Wavelength Range

Complex refractive index and complex dielectric permittivity and loss tangent data for polyethylene, polypropylene, poly-4 methyl-perrtene1 (TPX), and polytetrafluorethylene (Teflon) are presented over the frequency range 60-300 GHz. All of these nonpolar polymers are extremely low-loss materials. As in the microwave region, polyethylene demonstrates exceptionally low-loss characteristics in the entire millimeter-wave region. Polar polymers such as nylon and plexiglass exhibit much higher absorption (nearly an order of magnitude higher) loss compared to nonpolar polymers.