Abstract: This paper presents a novel unequal cross-slot coupled circularly polarized microstrip antenna excited by coplanar waveguide (CPW), which is convenient to be integrated with active circuits. Influence of the antenna’s size on the characteristics is analyzed using an electromagnetic simulator. A prototype is designed and fabricated. The measured results are in good agreement with simulation. The measured bandwidth of VSWR below 2 reaches 600MHz and axial ratio is 1.7dB in the main direction, with 3dB bandwidth of 140MHz at the central frequency of 10.28GH. Good circular polarization performance has been shown in experiments.

Key words: microstrip antenna, circular polarization, coplanar waveguide(CPW), coupling feed