Analysis and design of dual reflector antennas for omnidirectional coverage

Radio base stations for point to multipoint communications can use a compact configuration employing a single circularly symmetrical shaped reflector surface fed by a coaxial conical horn, producing cosecant squared-like power patterns in the vertical plane to account for free space attenuation, while concentrating radiated energy below the horizon line for reduced interference. A dual reflector arrangement, showing good potential for larger bandwidth applications and being particularly interesting for systems operating at higher frequencies, e.g. millimeter waves, has been suggested. This paper, using the MoM analysis tool for both reflector and feed structures, explores this configuration with two case studies.