Implementation of a novel two port four element rectangular patch array antenna with tunable circular polarization

Design of a circularly polarized four element patch array antenna is discussed. The proposed design consists of two ports each of them placed on either sides of the radiating elements. Due to the presence of two ports, the idea of using the antenna also as a filter element is explained. The concept of encrypted polarization is introduced where circularly polarized radiated waves can be left-handed or right-handed at a particular instant in time. This shift in polarization state is controllable and switchable dynamically. Simulated results successfully validate this idea.