This article demonstrates the design development, fabrication, and testing of an off-set 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, S11 < -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 gained 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-3.30 GHz (Axial ratio: 1.61 dB) and 9.07 GHz-9.45 GHz (Axial ratio: 2 dB) and elsewhere linearly polarized. A total of 16.37% antenna size miniaturization has been achieved with excellent UWB and S11 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 (5.725-5.875 GHz), WLAN (3.6/4.9/5.0/5.9 GHz), military band applications (radio location, fixed-satellite and mobile-satellite, S-band, C-band and X-band satellite communications, etc.), aeronautical radio navigation, radio astronomy, ITU-8, Sub-6 GHz band, and Radar applications.
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