Generación de campo polarizado circularmente en geometría plana con alimentación asimétrica

This paper presents a novel feeding system for obtaining circular polarized microstrip antennas, which is based on electromagnetic coupling in a single layer. The proposed circularly-polarized (CP) operation can be achieved simply by lengthening a microstrip line in the feeding system, without modifying the microstrip radiator. From the experimental results, the 3-dB axial-ratio bandwidth can reach as large as 98 MHz (3.9% relative to the center frequency of 2.44MHz) for the application as a 2.45-GHz RFID reader, or communication in ISM band