Focal Length of a Low Permittivity Plano-Convex Lens at Frequencies 30-600 GHz

Due to interest in lenses at telecommunicatons in the lower frequency range of 30—600 GHz (5G/6G applications) sub-terahertz range lenses have started to make their appearance. Geometrical optics is typically used due to its faster calculation speed, which is faster than finite element methods (FEMs). A 30-mm plano-convex lens was simulated with a COMSOL ray tracing module and CST was used to simulate 30, 60, 300 and 600 GHz FEM simulations. Focal points were 248, 189, 180, 118 and 131 mm with CST and 253 mm with COMSOL.