Fauzi Elmegri

Aperture-Coupled Asymmetric Dielectric Resonators Antenna for Wideband Applications

A compact dielectric resonator antenna (DRA) for wideband applications is proposed. Two cylindrical dielectric resonators that are asymmetrically located with respect to the center of a rectangular coupling aperture are fed through this aperture. By optimizing the design parameters, an impedance bandwidth of about 29%, covering the frequency range from 9.62 to 12.9 GHz, and a gain of 8 dBi are obtained. Design details of the proposed antenna and the results of both simulation and experiment are presented and discussed.

Compact Dielectric Resonator Antenna with Band-Notched Characteristics for Ultra-Wideband Applications

In this paper, a compact dielectric resonator antenna (DRA) with band-notched characteristics for ultra-wideband applications is presented. A comprehensive parametric study was carried out using CST Microwave Studio Suite TM 2011 to analyze and optimize the characteristics of the proposed antenna. Three shapes for the coupling slot were investigated. Simulation results show that the proposed DRA had a −10 dB impedance bandwidth of 23% from 9.97 GHz to 12.558 GHz, and a maximum gain of 7.23 dBi. The antenna had a notched band centered at 10.57 GHz, which increased the reflection coefficient by 23.5 dB, and reduced the gain by 6.12 dB. The optimized designs were verified by experimental tests on fabricated samples.

Dielectric resonator antenna design for UWB applications

A small dielectric resonator antenna has been designed for ultra wideband (UWB) communication system applications. The antenna element is a rectangular low permittivity ceramic block, with a dielectric constant of 9.4, and the modified T-shaped feed network includes a 50 ohm microstrip line to achieve strong coupling, and some bandwidth enhancement. The antenna performance is simulated and measured over a frequency band extending from 3100 MHz to 5500 MHz; the impedance bandwidth over this interval is 55.8% with VSWR <; 2, making the antenna suitable for UWB applications.

Rectangular slot fed asymmetric Cylindrical Dielectric Resonators antenna for wideband applications

Two Cylindrical Dielectric Resonators DR asymmetrically placed on a thin dielectric substrate and fed by a single rectangular slot for wideband wireless applications are presented. Optimized design procedures were applied within a well-known electromagnetic solver to achieve the improved elements dimensions of the antenna geometry. The simulated and measured results show that the proposed DRA can achieve 29% relative bandwidth at 10 dB return loss covering the spectrum range from 9.62 GHz to 12.9 GHz with a maximum gain of 8 dBi.

Automatic liquid level indication and control using passive UHF RFID tags

This paper proposes a new perspective to the liquid level monitoring and control technique by deploying energy efficient passive UHF RFID tags as liquid level sensors. The system consists of the pump, storage tank, level sensors (passive tags), RFID tag reader, pump control circuit, alarm circuit, and an indicator circuit. The tags are sealed (air and water tight), programmed with unique level labels using the Alien Reader software(860-868MHZ) and deployed to various levels of a storage tank for level monitoring and control. The mirrored P-shaped tag is designed modelled and deployed for use as the liquid level sensors. The RFID reader is disguised to form a part of the tank cover literarily few inches away from the tags. A variation of the tag readings received is used to infer level information which is communicated via the reader middleware to a computer database for monitoring.

An Evaluation of Spatial Modulation for MIMO Systems with QO-STBC

Simplified designs of multi-antenna systems with optimum efficiency are receiving attentions. Such simplicities also involve low cost architectures. In this study, we report an evaluation of a new multi-antenna scheme, namely, spatial modulation (SM) that is compared with quasi-orthogonal space time block codes (QOSTBC) scheme over Rayleigh fading channel. The SM scheme has been, earlier, compared with space time block codes (STBC) – a two antenna transmit diversity scheme that achieves full diversity when only two antennas are used. This is extended to QOSTBC scheme that absolves some decoding limitations to attain full diversity. It will be shown that, using the QOSTBC of similar architecture with the SM, even better performance can be achieved in favour of QOSTBC.

Broadband dielectric resonator antenna (DRA) design for mobile wireless applications

This paper presents a broadband dielectric resonator antenna operating from 1.15 to 6 GHz to cover most of the existing wireless mobile standards. This antenna assembly is constructed by a printed monopole antenna and a defected cylindrical dielectric resonator. The broad impedance bandwidth of this antenna is achieved by loading the crescent shaped radiator of the printed monopole antenna with a high permittivity dielectric material of 81. The envelope size of this antenna is 57 × 37.5 × 5.8 mm3. The simulated results in term of return loss, far field and gain of this antenna were shown and compared with the published work. The results of parametric study of this antenna were given in order to understand the influence of the permittivity and the height of the dielectric resonator to the return loss of the antenna. These results have demonstrated that the proposed antenna is potential candidate for mobile handset application.

Current technologies and location based services

This paper examines the benefits and drawbacks of these services, reviewing differences in infrastructure, power requirements, sensing devices, and other factors. Technologies covered include Radio Frequency Identification, GSM, GPS, A-GPS, Smart Antennas, Distributed Antenna Systems, Localization by Cell-ID, Localization by Prediction (Dead Reckoning method), Angle of Arrival (AOA), Localization by Finger Printing, Localization by Time of Arrival (TOA), Localization by Observed Time Difference of Arrival (TDOA), and Hybrid Localization-based AOA-TOA.

Design framework for unobtrusive patient location recognition using passive RFID and particle filtering

The remarkable growth in wireless communication technologies in recent times has motivated the synergy between wireless systems and medical sciences for improved healthcare services. Several emerging wireless technologies and approaches have therefore been proposed to achieve various efficient monitoring systems for health-related activities. In this paper, localisation of a patient using the ranging approach of received signal strength from passive RFID was proposed in the form of smart room. The proposed system is modelled based on a three-level intelligent model of transition, signal measurement and location sensing. The measured RSS is analysed using particle filtering algorithm as a means of localising the position of the target in indoor environments. The system was simulated in a test bed environment using wireless insite with satisfactory results. The system is aimed at achieving a non-wearable sensor approach that is unobtrusive and non-invasive for recognition of activity and location of critically-ill patients and the elderly for timely and reliable healthcare intervention.

Arc-shaped monopole antennas with reduced coupling for WLAN and WIMAX applications

An arc-shaped planar-monopole two antennas for WLAN and WiMAX application is proposed. The lengths of the two arcs are designed to meet the requirements for the WLAN and WiMAX standard sat 2.45GHz and 3.5GHz respectively. The separation between centers of the two feed lines is 14 mm (0.098 wavelengths at 2.45GHz).A new technique is proposed to reduce the mutual coupling between the two closely-spaced antennas by etching slots in the feed line of each antenna. The slots are in the form of two interlaced letter U. In each antenna, the slot is tuned to resonate at the operating frequency of the other antenna so that the signal coupled from the other antenna is blocked from reaching the antenna port. The antenna performance was investigated by simulation using CST Microwave Studio software. The results show that the proposed method has reduced the envelope correlation coefficient by 246 folds at the 2.45 GHz, and 11 folds at the 3.5GHz frequency bands. Measured S-parameters verified the simulated results.