Main-Reflector Shaping of Omnidirectional Dual Reflectors Using Local Conic Sections

This work presents an alternative method for GO synthesis of dual-reflector antennas suited for omnidirectional coverage. Both reflectors are bodies-of-revolution where a single conic section generates the sub-reflector while a concatenation of local conic sections represent the main-reflector generatrix, which is shaped to provide an arbitrary radiation pattern in the antenna's elevation plane. To illustrate the method, omnidirectional axis-displaced ellipse (OADE) configurations are synthesized to provide a cosecant squared radiation pattern in the elevation plane. Two different ray structures are considered: with real or virtual main-reflector caustics. The GO shaping results are validated by method-of- moments simulations.