A Compact Off-set Edge Fed Odd-symmetric Hybrid Fractal Slotted Antenna for UWB and Space Applications

This article demonstrates the design development, fabrication, and testing of an offset edge-fed monopole hybrid fractal antenna for ultra-wideband (UWB) applications at a design frequency of 3.2 GHz.The proposed monopole antenna is compact 38.12 mm × 38.42 mm, slotted, and uses a combination of two numbers of Koch plus Minkowski hybrid fractal technology.Antenna resonates at four frequencies, i.e., quad tuned (3.2 GHz, 4.94 GHz, 7.21 GHz, and 10.10 GHz).The reflection coefficient, S 11 < -10 dB obtained for the excellent UWB fractional bandwidth 119.55% (2.85 GHz to 11.32 GHz) is more than the standard FCC bandwidth (3.1 GHz-10.6 GHz).The antenna has gain 6.73 dBi at 3.49 GHz, 5.91 dBi at 5.52 GHz, 8.26 dBi at 6.81 GHz, and 8.02 dBi at 10 GHz with a maximum radiation efficiency of 89.81%.The main feature of the proposed work is that the antenna is circularly polarized in frequency bands 3.14 GHz-3.30GHz (Axial ratio: 1.61 dB) and 9.07 GHz-9.45GHz (Axial ratio: 2 dB) and elsewhere linearly polarized.A total of 16.37% antenna size miniaturization has been achieved with excellent UWB and S 11 performance.The measured and simulated reflection coefficients are found in good agreement.Therefore, the fabricated and tested antenna is well suitable for Wi-Max (3.3/3.5/5.5 GHz), ISM (5.725-5.875GHz), WLAN (3.6/4.9/5.0/5.9GHz), military band applications (radio location, fixed-satellite and mobile-satellite, S-band, C-band, and X-band satellite communications, etc.