Suspended rectangular and circular broadband patch antennas for circular polarization

In this paper we present a suspended rectangular and circular patch circularly polarized (CP) microstrip antenna with coplanar capacitive feed. Of the two circularly polarized (CP) antennas presented here, the first antenna uses fractal geometry with center slot within the rectangular patch and other having two perpendicular slots etched on circular patch in order to get circular polarization. The first antenna has an axial ratio bandwidth (<; 3dB) of 7.1% and a much higher impedance bandwidth of about 49% (S₁₁<;-10 dB) and also yields return loss better than -15dB in the useful range of circular polarization. After presenting the first geometry we proposed the second geometry (circular patch) which has simple geometry as compared to first geometry (fractal rectangular patch), which also offers circular polarization, with axial ratio bandwidth (AR <; 3dB) of 7.85% and also the geometry having high impedance bandwidth similar to first geometry of 53% (S₁₁<;-10 dB) and S₁₁ is well below -20 dB in range of CP operation. Measured values fairly agree with the simulated results.