Enhancing the Radiation Pattern of Circularly Polarized Dielectric Rod Antenna Using Planar Excitation Method

In this article, by placing a teflon tube around a circularly polarized dielectric resonator antenna, a dielectric rod antenna with a directive radiation pattern is obtained. In fact, a new planar method for the excitation of circularly polarized dielectric rod antenna is proposed, which produces lower back-lobe and sidelobe levels in antenna radiation pattern compared to other planar feeding methods of circularly polarized dielectric rod antenna. It can be seen that the use of dielectric resonator inside the Teflon tube has increased the coupling of electromagnetic waves from slot aperture to dielectric rod. A prototype of the proposed antenna has been fabricated and tested, and its results are in good agreement with the simulation results. Antenna measurements display an impedance bandwidth of 15.9% from 7.96 to 9.33 GHz, an axial ratio bandwidth of 13.4% from 8 to 9.15 GHz, and a LHCP gain between 11.8 and 14.4 dB. A radiation efficiency of greater than 92% is achieved in the entire operating bandwidth of the antenna.