Study of Environmentally-Friendly Radomes Using Cork-Rubber Composites for 5G Backhaul Links at E-band

Polymer-based materials face increasing limitations imposed by the U.S.A. and European legislation due to their environmental impact, namely carbon footprint and recycling capabilities containing polyfluoroalkyl (PFA) substances. Radome antennas often use these materials due to their electrical and mechanical properties and, therefore, there is a search for alternative dielectrics. Here, we evaluate the performance of cork + nitrile rubber and cork + chloroprene rubber composites to be used in radomes at E-band for 5G backhaul communications. Both materials present a dielectric constant of around 1.6 and a loss tangent of 5x10 ^-2 at 50 GHz. We fabricated a 1-foot parabolic reflector antenna which we covered with a cork-rubber radome. We measured the radiation pattern and isotropic gain across the 71–86 GHz frequency band, showing overall correct results, and indicating that the cross-polarization slightly deteriorates with the use of cor k+rubber and the gain drops by around 1 dB, when compared to an ABS radome used by the majority of telecom equipment manufacturers.