Characterization of mmWave radomes for base stations and automotive radars

In this paper, we have characterized dielectric properties of low-loss radome materials with three different measurement methods, at microwave and mmWave frequencies. The techniques include an over-the-air (OTA) far-field measurement at 55-95 GHz, a Fabry-Perot open resonator (10-60 GHz), and a split-post dielectric resonator whose empty resonance frequency is 2.45 GHz. Both resonator methods give very similar values for the dielectric constant and loss tangent, but the OTA measurement overestimates the dielectric constant by 8% and has larger variation between loss tangent values of different materials. Finally, it is evaluated how uncertainty in dielectric properties affect the radome performance.