MSc.Thesis Defense:İrem Aylin Duru

LINEAR AND CIRCULAR POLARIZED CIRCULAR ARRAY ANTENNAS UTILIZING ORBITAL ANGULAR MOMENTUM FOR WIRELESS APPLICATIONS AT 6.5 GHZ BAND

İrem Aylin DURU
Electronics Engineering, MSc. Thesis, 2024

Thesis Jury

Prof. İbrahim Tekin (Thesis Advisor), Prof. Özgür Gürbüz

, Assoc. Prof. Sema Dumanlı Oktar

Date & Time: 23th July, 2024 –  13.00

Place: FENS L067

Keywords : orbital angular momentum, linear and circular polarization, uniform circular array antennas, wireless communication

Abstract

This study investigates the design, fabrication, and performance evaluation of circular array antennas capable of generating and detecting Orbital Angular Momentum (OAM) at 6.5 GHz. Two sets of 4-element circular antenna arrays, one for linear polarization and the other for circular polarization, were constructed using RO4003 material. Simulations using HFSS showed these antennas can double capacity at 6.5 GHz by generating vortex waves with mode numbers l = ±1 and achieve gains over 7.5 dBi. The antennas were fabricated with an LPKF Circuit Board Plotter ProtoMat S63, ensuring high precision. Measurements in an anechoic chamber validated their performance, highlighting the superior spectral efficiency and interference resilience of circularly polarized antennas. Prototypes were tested, demonstrating effective OAM-enabled radio links and phase distribution patterns consistent with vortex wave theory. This research advances OAM in wireless communications, showing its potential to enhance spectral efficiency and robustness. Future work includes developing a 4-port antenna, increasing array elements, exploring advanced PCB techniques, extending frequency studies, conducting field tests, and improving interference mitigation.