• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • Tagged with
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Investigation of rectangular, uni-directional, horizontally polarised waveguide antennas with longitudinal slotted arrays operating at 2.45 GHz

Perovic, Una 14 November 2006 (has links)
Student Number : 0002066T - MSc dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built Environment / Investigations 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.
2

Distributed effects in power transistors and the optimization of the layouts of AlGaN/GaN HFETs

Lee, Sunyoung 08 August 2006 (has links)
No description available.
3

Flíčková anténa s budicí štěrbinou / Centre-fed microstrip patch antenna

Jireček, Martin January 2011 (has links)
Systems with extreme bandwidth are part of advanced modern systems at radio high capacitive communication. Originally this technology was intended for radar scan. Thanks to wide frequency band had radar possibility „ see" a behind crimp, e.g. behind woody partitions etc . To his noise immunity, fail safe tapping plus small wattage heftiness began use for datal systŽm function. If is elementary antenna compound from coaxial probe and shorting outlet, it is possible use to actuating separate narrow slot placed in the middle of incandescent dabs. Impedance and radiating characteristics conventionally plumbed phlobaphene antennae excited tape lead and suggested microstrip phlobaphene antennae are experimentally explored plus collated. Explored is so and effect changes slotted longitude slot on characteristics elementary antenna.

Page generated in 0.0705 seconds