Low-THz transmission through liquid contaminants on antenna radome

The effect of a uniform layer of petroleum-based fuels, gasoline and diesel, on wave propagation through a radome at 150 GHz and 300 GHz is presented in this paper. Transmissivity through gasoline and diesel is studied theoretically and empirically. The measured results are compared with a theoretical calculation and are found to be in good agreement. Transmissivity higher than −2 dB and −5 dB is measured through a 15 mm layer of diesel at 150 GHz and 300 GHz, respectively. Transmissivity through a 15 mm uniform layer of gasoline is recorded to be about −15 dB for both frequencies. However, the antenna radome for outdoor automotive applications is more likely to be covered by diesel than gasoline, due to the weaker dispersion and faster evaporation of gasoline.