Focal Region Ray Tracing of Dual Spherical Reflector Antenna

5G mobile communications require multibeam base station antenna to operate at millimeter frequency band. Therefore, dual spherical antenna is promising for 5G application. As for achieving high gain, optimum antenna configuration should be found out. In this paper, the focal region ray tracing method is developed. Firstly, analytical equations for the focal region ray tracing are clarified. The key equation of determining the caustic position is then solved by MATLAB program. In addition, some ray tracing results are shown to ensure the usefulness of the developed ray tracing method.