PhD Dissertation: Abdulkadir Uzun, DESIGN AND ANALYSIS OF MULTI-MODE ORBITAL ANGULAR MOMENTUM ANTENNAS FOR WIRELESS COMMUNICATIONS, Date & Time: July 06, 2026 – 3:00 PM, Place: FENS G025

DESIGN AND ANALYSIS OF MULTI-MODE ORBITAL ANGULAR MOMENTUM ANTENNAS FOR WIRELESS COMMUNICATIONS

Abdulkadir Uzun
Electronics Engineering, PhD Dissertation, 2026

Thesis Jury

     Prof. İbrahim Tekin (Thesis Advisor)

  Prof. Özgür Gürbüz

  Prof. Hüsnü Yenigün

Prof. Hatice Özlem Aydın Çivi

Prof. Nurhan Türker Tokan

Date & Time: July 6th, 2026 – 03:00 PM

Place: FENS G025

Keywords : Orbital Angular Momentum, Uniform Circular Arrays, Series-Fed

Antennas, Dual Polarization, Microstrip Antennas

Abstract

This thesis presents the design, analysis, fabrication, and experimental validation of compact series-fed uniform circular array (UCA) antennas for orbital angular momentum (OAM) generation. A comprehensive framework is developed to realize low-order OAM modes using single-layer microstrip array architectures. Three antenna configurations are proposed: a dual-mode linearly polarized antenna generating ℓ = ±1 modes, a dual-mode dual-linearly polarized antenna supporting orthogonally polarized ℓ = ±1 modes, and a multi-mode dual-linearly polarized antenna capable of generating orthogonally polarized ℓ = ±1 and ℓ = ±2 modes within a single array. The proposed designs employ novel series-fed networks that provide the required inter-element phase progression via port excitation alone, eliminating the need for multilayer structures, active components, and external phase shifters. Experimental results, including S-parameter measurements, radiation patterns, phase distributions, OAM spectra, and transmission measurements, confirm successful generation of the desired OAM modes. The developed antennas offer compact size, low-profile implementation, reconfigurable operation, and satisfactory OAM mode purity. The proposed architectures enable the combined use of OAM modes and orthogonal polarizations within a single antenna structure. By providing compact and scalable OAM antennas, this work contributes to future high-capacity wireless communication systems, MIMO platforms, unmanned aerial vehicles, and Internet-of-Things applications.