PROJECT TITLE :

Circularly Polarized Square-Ring Antenna Loaded With Reactive Components

ABSTRACT:

In this study, a completely unique, straightforward single-feed square-ring antenna is proposed for circular polarization (CP) operation. The planning procedure involves three stages. In the primary step, a conventional square-ring antenna is loaded with an open gap at specific locations along the sq. ring. This antenna exhibits 2 resonance characteristics ( and ) with polarizations orthogonal to each other. This antenna works as a dual-band dual-linear polarized antenna. Within the second step, the second resonant frequency ( ) is controlled without varying the primary resonant frequency ( ) by embedding a lumped-chip capacitor/inductor in the open gap of the sq.-ring antenna. Therefore, the antenna contains a tunable frequency ratio ( ). By selecting a appropriate lumped part, 2 proximal resonant frequencies are obtained, and 2 orthogonal resonant modes with a 90° phase difference are excited. Finally, pure CP is obtained. In the last stage, a lumped part is realized using a distributed element. Numerous prototypes of the proposed antenna are implemented, and their performance is measured. The measurement results show that radiation patterns with good CP characteristics are obtained at the resonant frequencies.