Reconfigurable Cellular Base Station Antenna Consisting of Parasitic Radiators

In this article, a beam-shaping technology, based on arrays of parasitic elements, is presented for the modulation of radiation patterns of existing 4G or 5G base station antennas. First, based on the cell's geographic topology and the requirements of different radiation power exposure, and using ray-tracing simulation, the desired antenna radiation patterns are determined and represented with spherical harmonics. Those patterns are implemented in a prototype in the 1800 MHz band using parasitic radiators, loaded with different impedances, to be placed in front of the existing cellular base station antenna. A smaller prototype demonstrates the electronic control of parasitic loads using varactor diodes. The developed prototypes have been tested in the laboratory and the measurements are in a good agreement with the simulation results.