The Impact of a Wet $S$ -Band Radome on Dual-Polarized Phased-Array Radar System Performance

This paper discusses the impact of a wet flat radome on the performance of a line replaceable unit active phased-array antenna developed for a dual-polarized phased-array weather radar. Water formations, such as film and droplets, were fully characterized over flat and curved radome surfaces using an analytical model as a function of the precipitation rate. Numerical simulations and experimental results validated the proposed analytical model. An active dual-polarized phased-array of 8 × 2 elements was used to evaluate the degradation of the crosspolarization component as well as the mismatch and the phase of scanned antenna radiation patterns for vertical and horizontal polarizations. In addition, a radome panel of an S-band weather radar (WSR-88D) was characterized in the far field using a single radio-frequency probe. It is demonstrated that even at the S-band, the water formation on the radome affects both copolarization and cross-polarization components, degrading the overall performance of the dual-polarized radar system under rain conditions.