Radiation Pattern Synthesis of Folded Geodesic Lens Antennas

Abstract

The fifth and sixth generation of mobile communication systems will allow the development of several new services. New millimetre-wave multibeam antennas are needed to provide wide and stable beams. Rotationally symmetric geodesic lens antennas (GLA) can fulfil these requirements. In this work, a two-step method to design folded GLAs is presented. In the first step, a folded focusing lens is searched such that its radiation pattern minimizes a cost function. In the second step, a genetic algorithm is run to diminish the value of the cost function. As an example, this method has been used to design a GLA with 24º of beamwidth and side lobe level below -15 dB. A multibeam antenna has been simulated based on this lens. The antenna is fed by nine ports, which ensures high overlapping between independent beams. This antenna can provide a coverage of 110º.