Microwave measurements for antenna radome maintenance and replacement

This paper describes microwave techniques and measurements done to evaluate radome replacement coatings on two antenna systems. One is a weather search radar (NEXRAD) and the other is a mobile satellite up/down link phased array antenna (AN/MSQ-118). For the weather search radar, S parameter transmission and reflection measurements were made on a coated radome panel in the near-field within an anechoic chamber. For the phased array antenna, two different sets of measurements were made on the coated radome, both in the reactive field. The first set was of transmission measurements made on coated film sections inserted in a waveguide. The second set was of transformed far-field antenna gain and pattern measurements, measured in an anechoic near-field chamber with different radome coatings. Dielectric constant and loss tangent measurements of these different coatings are also given.