Circularly polarized microstrip patch antenna fed by substrate integrated waveguide

This paper presents a circularly polarized microstrip patch antenna fed by a substrate integrated waveguide. The antenna was designed in Ansoft HFSS for the operating frequency 10 GHz. The antenna works with right-handed circular polarization. At the desired frequency, the antenna reaches 4.4% impedance bandwidth (the measured value for s
₁₁
better than -10 dB), 7.1% Axial Ratio (AR) bandwidth (the simulated value for AR <; 3) and the simulated gain 9.3 dBi.