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  • 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.
161

Offset Aperture-Coupled Double-Cylinder Dielectric Resonator Antenna with Extended Wideband

Zebiri, Chemseddine, Lashab, Mohamed, Sayad, D., Elfergani, Issa T., Sayidmarie, Khalil H., Benabdelaziz, F., Abd-Alhameed, Raed, Rodriguez, Jonathan, Noras, James M. January 2017 (has links)
Yes / A compact dielectric resonator antenna for ultra-wideband vehicular communication applications is proposed. Two cylindrical dielectric resonators are asymmetrically located with respect to the center of an offset rectangular coupling aperture, through which they are fed. Optimizing the design parameters results in an impedance bandwidth of 21%, covering the range from 5.9 to 7.32 GHz in the lower-band and a 53% relative bandwidth from 8.72 to 15 GHz in the upper-band. The maximum achieved gain is 12 dBi. Design details of the proposed antenna and the results of both simulations and experiment are presented and discussed.
162

Metal-Only and Mechanically Reconfigurable Reflectarrays

Henderson, Kendrick 09 November 2022 (has links)
No description available.
163

Explanation of DC/RF Loci for Active Patch Antennas

Ali, N.T., Hussaini, Abubakar S., Abd-Alhameed, Raed, Child, Mark B., Rodriguez, Jonathan, McEwan, Neil J., El-Khazmi, E.A. January 2010 (has links)
Yes / A characteristic loop locus of dc power versus RF output power was observed as the frequency was varied around the optimum point of an operational active antenna. A new technique was introduced into the simulation, plotting the dependence of parameters such as supply current, efficiency or output power on internal impedance as seen by the naked transistor. It is now clear that the loop was formed as a consequence of the interaction of the transistor packaging elements with the patch impedances.
164

DIGITAL DIRECTION FINDING SYSTEM DESIGN AND ANALYSIS

LIU, HUAZHOU 02 September 2003 (has links)
No description available.
165

Validation of NEC-3 (Numerical Electromagnetics Code) with applications to MF and HF antenna technology

Christman, Alan M. January 1990 (has links)
No description available.
166

DUAL FREQUENCY PATCH ANTENNA DESIGN FOR GLOBAL NAVIGATION SATELLITE SYSTEM

Chen, Luyi 02 August 2007 (has links)
No description available.
167

Compact Smart Antenna With Electronic Beam-Switching and Reconfigurable Polarizations.

Gu, C., Gao, S., Liu, H., Luo, Q., Loh, T-H., Sobhy, M., Li, J., Wei, G., Xu, J., Qin, F., Sanz-Izquierdo, B., Abd-Alhameed, Raed 10 1900 (has links)
yes / This paper presents a compact-size, low-cost smart antenna with electronically switchable radiation patterns, and reconfigurable polarizations. This antenna can be dynamically switched to realize three different polarizations including two orthogonal linear polarizations and one diagonally linear polarization. By closely placing several electronically reconfigurable parasitic elements around the driven antenna, the beam switching can be achieved in any of the three polarization states. In this design, a polarization reconfigurable square patch antenna with a simple feeding network is used as the driven element. The parasitic element is composed of a printed dipole with a PIN diode. Using different combinations of PIN diode ON/OFF states, the radiation pattern can be switched toward different directions to cover an angle range of 0◦ to 360◦ in the azimuth plane. The concept is confirmed by a series of measurements. This smart antenna has the advantages of compact size, low cost, low power consumption, reconfigurable polarizations, and beams.
168

Compact size uni-planer small metamaterial-inspired antenna for UWB applications

Jan, Naeem A., Elmegri, Fauzi, Bin-Melha, Mohammed S., Abd-Alhameed, Raed, Lashab, Mohamed, See, Chan H. January 2015 (has links)
No / In this paper, low profile planar Metamaterial-Inspired coplanar fed waveguide antenna is presented for WLAN and Ultra-Wideband applications. The antenna is based on a simple strip loaded to a rectangular patch and zigzag E-shape metamaterial-inspired unit cell. The idea behind the proposed antenna is to enable miniaturization effect. The proposed antenna can provide dual band operation, the first one is a Wi-Fi band at 2.45 GHz having impedance bandwidth of 150MHz, the second one is an ultra wide band extended from 4.2 GHz to 6.5 GHz. Two antennas are designed and fabricated with and without metamaterial-inspired loading. The simulated and measured results regarding Return loss (S11), Gain and Radiation pattern are discussed.
169

A planar dual-polarized phased array with broad bandwidth and quasi end-fire radiation for 5G mobile handsets

Ojaroudi Parchin, Naser, Zhang, J., Abd-Alhameed, Raed, Pedersen, G.F., Zhang, S. 11 April 2021 (has links)
Yes / A planar dual-polarized phased array is proposed for 5G cellular communications. The array has the properties of dual-polarization, wideband and quasi end-fire radiation, which is printed on one side of a single-layer substrate. The design contains two 8-element sub-arrays including horizontally polarized end-fire dipole antennas and vertically polarized end-fire periodic slot antennas, employed on the PCB ground plane of the 5G mobile platform. Both sub-arrays provide wide bandwidth to cover 28 and 38 GHz (promising 5G candidate bands). The -10 dB impedance bandwidth of the proposed CPW-fed dipole and slot antennas are 26.5-39.5 GHz and 27.1-45.5 GHz, respectively. Moreover, for -6 dB impedance bandwidth, these values could be more than 20 GHz (24.4-46.4 GHz for the dipole antenna) and 70 GHz (22.3-95 GHz for the slot antenna). The fundamental characteristics of the proposed dual-polarized 5G antenna array in terms of the impedance bandwidth, realized gain, polarization, radiation pattern, and beam steering are investigated and good results are obtained. The clearance of the proposed dual-polarized 5G antenna array is less than 4.5 mm which is sufficient for cellular applications. / This work is partially supported by the InnovationsFonden project of Reconfigurable Arrays for Next Generation Efficiency (RANGE), AAU Young Talent Program, and European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016SECRET-722424.
170

A Frequency Tunable PIFA Design for Handset Applications

Elfergani, Issa T., Abd-Alhameed, Raed, Bin-Melha, Mohammed S., See, Chan H., Zhou, Dawei, Child, Mark B., Excell, Peter S. January 2010 (has links)
Yes / A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is tunable over from 1850 MHz to 2200 MHz, with an associated volume of 21×13.5×5 mm3, making it suitable for potential integration in a commercial handset or mobile user terminal.

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