Performance analysis of circularly polarized dual annular ring patch antenna for MIMO satellite application

In this paper, a dual annular ring patch antenna with high isolation for Multiple Input Multiple Output (MIMO) Satellite application at 4 GHz is presented. The mutual coupling reduction and circular polarization are achieved by some perturbations in annular ring patch and microstrip stubs between antennas. These perturbations will excite two modes which is orthogonal ie. equal amplitude and phase shift to make it circularly polarized. The antenna design is fabricated on a substrate with permittivity 4.4 and 1.6 mm thickness. The simulated results are studied and analyzed for the proposed antenna. The isolation of better than 30 dB, axial ratio lower than 3 dB and gain of about 3.4 dB are obtained. The performance characteristics are simulated, measured and analyzed with different antenna parameters. The validated antenna shows that the simulated and measured results are in good agreement with each other.