π-shaped circularly polarized high-gain Minkowski fractal antenna for radar applications

This article investigates a compact pi-shaped circularly polarized Minkowski fractal antenna (MFA). The proposed radiator is taking a pi-shape with semicircular cuts along the opposite side of the patch with a V-cut at the bottom. A second-order Minkowski fractal curve is implemented on the bottom ground plane. The antenna element is powered by a coaxial probe. The asymmetric structure generates two orthogonal modes, which results in circular polarization. A maximum gain response of 7.1 dBic is observed in the impedance band width (IBW) covering 9.7 to 11.2 GHz. The patch is fabricated on substrate RT/Duroid 5880 (TM) (epsilon(r)=2.2). The antenna has a compact dimension of 0.90 lambda(0) x 0.90 lambda(0) x 0.05 lambda(0) (f(r) = 10.45 GHz). A good match in the results validates the simulated and measured data in comparison with the existing models from literature with respect to diversity performance, thus making it suitable for radar applications.