A single-feed tri-band conformal circularly polarized dual-annular slot antenna

Abstract

This paper presents a compact single-feed tri-band conformal circularly polarized dual-annular slot antenna. The antenna is composed of two concentric annular slots etched in a ground plane feeding with a microstrip line. By etching two symmetrical clockwise bending branches and two semi-elliptical slots connecting with the outer annular slot, circular polarization radiation is obtained at 2.45 GHz. The inner shorted annular slots can generate circular polarization radiation at 4.15/5.8 GHz. Finally, the proposed antenna is conformal to a cylinder with a radius of 50 mm.