A NOVEL DESIGN OF A MICROSTRIP FED SHORTED SQUARE-RING SLOT ANTENNA FOR CIRCULAR POLARIZATION

摘要

The design of a circularly polarized slot antenna fed by a single microstrip line is presented. The circularly polarized radiation is achieved by means of using a shorted square-ring slot. This proposed antenna has the fundamental resonant frequency of 2.4 GHz with the minimum return loss of -50.44 dB. The impedance bandwidth is 930 MHz or 38.7% referred to the resonant frequency, and it also has the 3-dB axial-ratio (AR) bandwidth of 310 MHz or 12.9% referred to the resonant frequency. In addition, this proposed antenna shows good performance of circular polarization (CP) radiation with the range of the lower 3-dB AR value covering elevation angles between -40 to 40 degrees.