Wide-Angle Radome Design for Low-Cost Additive Manufacturing

Abstract: The radome, a portmanteau of the words radar and dome, is a protective dielectric cover to protect a radar from its surrounding environment. The surrounding environment can be rain, wind, sand, dust and whatever else that might harm the radar. Radomes come in many different shapes, materials and thicknesses, where each of these parameters are decided based on the need for the given radar application. The challenge is that the protective radome decreases transmission and increases reflection of the electromagnetic wave; especially for larger angles of incidence which limits the effective field-of-view. In this project we present methods to more easily design and optimize multilayered radome structures that decrease reflections and increase transmission for a larger range of angles of incidence. Our method is to combine transmission line calculations and optimization algorithms with finite element method simulations software, where the transmission line calculations can considerably speed up and simplify an initial design. The optimization is performed for all angles of incidence of interest simultaneously, as well as the possibility to optimize for both transverse electric and transverse magnetic polarization. The design method can be used with any material and at frequencies for mmWave applications to achieve a goal of designing radomes that have reflectance below −25 dB up to 50◦ angles of incidence. In our thesis we found, for flat multilayer radome structures, that the transmission line calculations are very consistent with the finite element method simulations. Furthermore, measurements of prototype radomes have been performed in order to validate the simulated structures and the viability of the design procedure.