Pattern reconfigurable antenna designs insub-6 ghz band for 5g applications

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2021-2-08
Çelik, Feza Turgay
In this thesis, design,simulations,fabrication, and radiation pattern measurementsof reconfigurable antennas for sub-6GHz application of 5G protocol are presented. Modeanalysis techniquesand array theory areemployed to have anunderstanding ofthe pattern reconfigurability conceptof the designs.As a first step, adual-fed rectangular patch antenna is designed,simulated,fabricated,and then measured. Even and odd mode definitions onthe rectangular patch antennas are employed in the design process. Designed antenna has a shorting plane located at its middle section. This shorting planedividesthe antenna into two sub-elementsthat are independent ofeach other.As each sub-element has its own excitationport, it is possibleto scan the main radiation direction of the antenna by applying phase differences between the ports. Designed antennascans from-400to +400in the elevation plane, which is orthogonal to shorting plane.Another printed antenna is designed based on the excitation of different modes ofdifferent resonators.Circularpatch and ring-shaped resonators are employed to create different radiation patterns. The cavity model isusedto analyze and design radiators. The radiators are arranged so that they operate atdifferent modes of cavity model. The ring is fed by two ports opposite to each other while the circular patch is parasitically excited. The applied phase difference between ports determines which radiator is excited more dominantly. Designedantenna also performsbeam scanningfrom-400to +400in the elevation plane along the feeding ports.To miniaturize, the antenna is loaded by capacitors. Antenna is fabricated,and design is validated by measurements.Arectangular patch antennathat includes four triangular sub-antenna elements is designed. This antenna employs the parasitic elements to steer its radiation direction. However, the phenomenon that resultsin beam scanning isnot limited tothe contributions of the parasitic elements. As the antenna consists of four independently excitedelements, operation with multiple elements also effectivelysteer the radiation beam. This design is capable of steeringthe radiated beam from -400to +400in elevation plane.
Citation Formats
F. T. Çelik, “Pattern reconfigurable antenna designs insub-6 ghz band for 5g applications,” M.S. - Master of Science, Middle East Technical University, 2021.