Advanced antenna solutions for milimeter wave 5G applications

This thesis presents the design and simulation of phased array antennas operating at 28 GHz for 5G wireless communication using CST Microwave Studio. The goal is to achieve high-gain, directional arrays with wide beam-steering and stable performance. Two single-element antennas, a slotted patch and a parasitic patch, were first designed and analyzed. Both showed good radiation characteristics, with the slotted element achieving a slightly higher gain of 8.4 dBi. These were then configured into two phased arrays: a 1×10 slotted array and a 1×8 parasitic array. The parasitic array achieved a wider steering range of −58° to +58°, a peak gain of 15.2 dBi, and a side-lobe level (SLL) of −14.9 dB, while the slotted array attained a higher gain of 18.5 dBi, SLL of −13.4 dB, and a steering range of −44° to +44°. The slotted array also maintained a more stable gain between 18.5 and 14.8 dBi, meeting the 5G requirement of at least 12 dBi, whereas the parasitic array's gain dropped to 9.6 dBi at some angles. Therefore, the slotted array was optimized using ten tapering techniques, with the exponential taper effectively reducing side lobes to −21.7 dB while maintaining about 18 dBi gain. A prototype was fabricated and measured, showing satisfactory agreement with simulation results despite minor fabrication variations. The CST results were further validated with HFSS, confirming consistency between both simulation platforms.