Perovic, Una2006-11-142006-11-142006-11-14http://hdl.handle.net/10539/1673Student Number : 0002066T - MSc dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built EnvironmentInvestigations of uni-directional, horizontally polarized waveguide antennas with longitudinal slotted arrays operating at 2.45GHz and their applications to wireless local area networks (WLAN) are presented in this paper. Requirements, considerations, and limitations associated with the design process of this particular waveguide are discussed and presented. Various antenna parameters were simulated using MATLAB® and SuperNEC® software simulation programs, and were applied to a sensitivity analysis of antenna design. End-fed and center-fed antennas were designed, built, and measured at WLAN frequencies. Measured antennas had high gain above 15dBi, broad beam around the azimuth, and high efficiency, but were limited by their impedance dependency and narrow bandwidth. The center-fed antenna had 3dBi higher gain than the 18dBi gain of the end-fed antenna. The VSWR ratio of both antennas was less than 1:1.5 at the operating frequency. The center-fed antenna had broader azimuth and elevation patterns by 40° and 10°, respectively. The end- fed antenna had more stable gain and VSWR, 50% wider VSWR bandwidth of 100MHz, and more directional elevation pattern. The design criteria generated using waveguide theory and simulated analysis was validated by the physical design and performance of the measured antennas.430520 bytesapplication/pdfenwaveguideWLANsuperneclongitudinal slotted arraysend-fedcenter-fedfree-space wavelengthThesis