New type of cavity-backed antenna with circular polarization

The paper presents a new type of cavity-backed antenna with circular polarization (CBACP) employing two printed orthogonally crossed dipoles having complex-conjugated impedances. The dipoles are fed by a symmetrical (balanced) microstrip line terminated with a balun and a coaxial SMA connector. Diameter and height of the cavity are: D=70mm and H=25mm, respectively while the central frequency of the antenna´s operating range is 5.3 GHz. VSWR is less than 2 in the 19 % of the frequency range and axial ratio (AR) is less than 3dB in the 4 % of the range. Aperture efficiencies with respect to directive and effective gain are 95 % and 75.7 %, respectively, representing, to our knowledge, the best result for this type of antenna structure.