Design and Analysis of Fractal Array Antenna for 5G mm Wave-FR2 Bands and Wireless Applications

This chapter presents fractal array antennas designed for millimeter-wave applications within the 24-40 GHz spectrum. The design features modified fractal antennas arranged in an array, connected through a hexagonal ring feed line with dimensions of 1.6 mm height and 900 mm² substrate area. Simulation results show significant improvements in peak gain (5.9- 6.9 dBi) for the fractal antenna designs with peak directivity of 6.89 and 7.13 dBi for dual-band radiation. Within the 5G NR bands, the antennas demonstrate enhanced radiation at 32 GHz and 36.6 GHz with specific angular orientations (Phi = 0°, Phi = 90°, Theta = 90°). The fractal slots concentrate current distribution, directing radiation at phi = 0° and Phi = 90°, achieving essential pencil beam properties for 5G millimeter-wave communication. The antennas achieve maximum return losses of 34 and 40 dB for dual-band radiation, with VSWR near unity at resonances. The array design covers 30.4-33.6 GHz bandwidths and 35.2-40 GHz, making them suitable for n259, n260, and n261 5G NR bands and ground-based radio navigation. The design's performance is validated through CST simulation and vector network analyzer measurements.