Polarization analysis of a cavity-backed circularly polarized slot antenna

A new type of Substrate Integrated Waveguide (SIW) based circularly polarized antenna is introduced in the paper. By means of comparison between the left and right circular polarization gain, the characteristic of antenna polarization is given out. Through deliberate research it is found that the gain of the proposed antenna is mainly influenced by the adjustment of the distance between the two parallel slots etched on the top metal surface which reaches the maximum of 7.3dB at the center frequency of 12GHz and the axial ratio (AR) reaches the lowest which is 1.03dB. In a conclusion the proposed antenna can be fabricated easily and has the merits of high gain, low AR.