Widad Ismail

Universiti Sains Malaysia, Electrical and Electronics Engineering, Faculty Member

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Steven Pinker

Harvard University

David Seamon

Kansas State University

Armando Marques-Guedes

UNL - New University of Lisbon

Iolanda Craifaleanu

Technical University Of Civil Engineering, Bucharest

Fabio Cuzzolin

Oxford Brookes University

Lev Manovich

Graduate Center of the City University of New York

Jaydip Sen

Praxis Business School

Isad Saric

University of Sarajevo

Hend Malhat

Menoufiya University

Mayra Zahra

State University of Jakarta

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Papers by Widad Ismail

System-level integration and simulation of ultra wideband receiver front-end

To determine the most appropriate design for ultra wideband (UWB) receiver front-end, a study was... more To determine the most appropriate design for ultra wideband (UWB) receiver front-end, a study was conducted on the designs of wideband antennas, wideband filters, and wideband amplifiers. Previous works on these devices have been analysed and compared for the following major parameters, which are antenna return loss, antenna bandwidth, filter bandwidth, filter insertion loss, filter return loss, amplifier gain, amplifier bandwidth, amplifier return loss, and amplifier noise figure. This work is to integrate wideband antenna, filter, and amplifier that were previously designed separately, into a complete UWB receiver front-end. The preferred designs for the integration are antipodal Vivaldi for the antenna, multiple-mode resonator (MMR) for the filter, and three cascaded Agilent HMMC-5200 series-shunt heterojunction bipolar transistor (HBT) amplifiers for the amplifier module. Setup and simulation of the antenna is performed using Agilent ADS Momentum while the simulations of the filter and UWB amplifier module are performed using Agilent ADS Schematic. The antipodal Vivaldi antenna achieves partial wideband capability with return loss below -10 dB between 3.3 GHz and 6.2 GHz. The MMR bandpass filter simulation realizes an almost maximally flat insertion loss response for the entire UWB passband that is from 3.1 GHz to 10.6 GHz and return loss below -15 dB throughout the passband. The UWB amplifier module demonstrates amplification from 28.7 dB to 30.3 dB and return loss below -17 dB from DC to 20 GHz. The front-end simulation realizes 25 dB to 29 dB of signal amplification within the UWB passband. The out-of-band rejection performances are 8.2 dB/GHz and -8.1 dB/GHz roll-off rates for the lower and upper stopband respectively. The link system also realizes low noise figure between 1.47 dB and 3.13 dB within the UWB passband.

Development of Java based RFID application programmable interface for heterogeneous RFID system

Journal of Systems and Software, 2010

Please cite this article in press as: Ali, M.F.M., et al., Development of Java based RFID applica... more Please cite this article in press as: Ali, M.F.M., et al., Development of Java based RFID application programmable interface for heterogeneous RFID system. a b s t r a c t Developing RFID based applications is a painstakingly difficult endeavor. The difficulties include nonstandard software and hardware peripherals from vendors, interoperability problems between different operating systems as well as lack of expertise in terms of low-level programming for RFID (i.e. steep learning curve). In order to address these difficulties, a reusable RFIDTM API (RFID Tracking & Monitoring Application Programmable Interface) for heterogeneous RFID system has been designed and implemented. The API has been successfully employed in a number of application prototypes including tracking of inventories as well as human/object tracking and tagging. Here, the module has been tested on a number of different types and configuration of active and passive readers including that LF and UHF Readers.

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Security Problems in an RFID System

Wireless Personal Communications, 2011

This paper focuses on the security and privacy threats being faced by the low-cost RFID communica... more This paper focuses on the security and privacy threats being faced by the low-cost RFID communication system, the most challenging of which relate to eavesdropping, impersonation, and tag cloning problems. The security issues can be improved and solved by utilizing both prevention and detection strategies. Prevention technique is needed since it offers resistance capabilities toward eavesdroppers and impersonators. Detection technique is vital to minimize the negative effects of tag cloning threats. This paper proposes the use of both prevention and detection techniques to make RFID communication more secure. Lightweight cryptographic algorithm, which conforms to the EPC Class-1 Generation-2 standard, is used in the proposed mutual authentication protocol for RFID system to raise security levels. In addition, electronic fingerprinting system is deployed in the proposed solution as a detection method to distinguish counterfeit and legitimate tags.

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A circularly polarized microstrip antenna array with Butler matrix

We have implemented a planar microstrip antenna array with a Butler matrix to form a switched bea... more We have implemented a planar microstrip antenna array with a Butler matrix to form a switched beam smart antenna array that ensures real time mobile tracking in dynamic environments. If the transmitting and receiving antennas are both linearly polarized the misalignment between antennas expected to occurs frequently and affects strongly on the performance of the mobile tracking system; in order

Analysis of Rain Attenuation Models for South East Asia Countries

Journal of Infrared Millimeter and Terahertz Waves, 2011

This paper presents an analysis of experimental data compared with existing rain attenuation pred... more This paper presents an analysis of experimental data compared with existing rain attenuation prediction models, namely, the Yamada, R&K, Crane, DAH and ITU models, which have been previously used in satellite communication systems. The experimental data were measured at the Universiti Sains Malaysia, Penang in the northern region of Peninsular Malaysia from 2007 to 2009 by receiving a Ku-band signal from the satellite SuperBird-C (geostationary at 144 °E). Data from Nigeria, Kenya, Indonesia, and PNG were obtained from the respective countries’ researchers. The DAH and ITU models were recommended as the most suitable models. The recommendation was made based on the model’s good performance compared with the measured data from the selected tropical countries.

A Microstrip Antenna Array for Indoor Wireless Dynamic Environments

IEEE Transactions on Antennas and Propagation, 2009

A planar microstrip antenna array with a Butler matrix has been implemented to form a microstrip ... more A planar microstrip antenna array with a Butler matrix has been implemented to form a microstrip antenna array that has narrow beamwidth, circular polarization, and polarization diversity. This microstrip antenna array improves the system performance in indoor wireless dynamic environments. A circularly polarized microstrip antenna array is designed such that it consists of four identical linearly polarized patches. A 2

Analysis of Aperture Coupled Microstrip Antenna with Circular Polarization Diversity

Wireless Personal Communications, 2011

The circular polarization diversity with the square patch microstrip antenna was obtained by the ... more The circular polarization diversity with the square patch microstrip antenna was obtained by the implantation of the quadrature hybrid as a microstrip feed line. The small size antenna is achieved by using the aperture coupled structure. The analysis of an aperture-coupled microstrip antenna (ACMSA) based on the cavity model theory is presented in this paper. The cavity model has been used to design an ACMSA and determine the relationship between the input impedance of the ACMSA and the position of the aperture. The matlab and the Advanced Design Software have been used for designing and simulating the ACMSA. There is a good agreement between the simulated and the experimental results.

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Circular polarisation diversity with small size microstrip antenna

International Journal of Electronics, 2009

The circular polarisation diversity with the square patch microstrip antenna was obtained by the ... more The circular polarisation diversity with the square patch microstrip antenna was obtained by the implantation of the quadrature hybrid as a microstrip feed line. The small size antenna is achieved by using the aperture coupled structure. The cavity model has been used to design an aperture coupled microstrip antenna (ACMSA) and determine the length of the open microstrip stub line in order to match microstrip antenna. The MATLAB and Advanced Design Software (ADS) have been used for designing and simulating the ACMSA. There is a good agreement between the simulated and the experimental results.

Satellite and ground data rainfall characterization in Malaysia

This work presents the validation of ground based rainfall measurement with TRMM products and GPC... more This work presents the validation of ground based rainfall measurement with TRMM products and GPCC data. The bias error between ground and satellite rainfall measurements was found to be ± 15 %. The TRMM 3B43 agreed with rain gauge rainfall measurement with correlation coefficient of 0.835. Consequently, for sea and remote areas where rain gauge cannot cover, TRMM 3B43 V6 is recommended for use in lieu of ground measurement in Malaysia and its environs.

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Analysis of Rain Attenuation Models for South East Asia Countries

This paper presents an analysis of experimental data compared with existing rain attenuation pred... more This paper presents an analysis of experimental data compared with existing rain attenuation prediction models, namely, the Yamada, R&K, Crane, DAH and ITU models, which have been previously used in satellite communication systems. The experimental data were measured at the Universiti Sains Malaysia, Penang in the northern region of Peninsular Malaysia from 2007 to 2009 by receiving a Ku-band signal from the satellite SuperBird-C (geostationary at 144 °E). Data from Nigeria, Kenya, Indonesia, and PNG were obtained from the respective countries' researchers. The DAH and ITU models were recommended as the most suitable models. The recommendation was made based on the model's good performance compared with the measured data from the selected tropical countries.

System-level integration and simulation of ultra wideband receiver front-end

Development of Java based RFID application programmable interface for heterogeneous RFID system

Journal of Systems and Software, 2010

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Security Problems in an RFID System

Wireless Personal Communications, 2011

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A circularly polarized microstrip antenna array with Butler matrix

Analysis of Rain Attenuation Models for South East Asia Countries

Journal of Infrared Millimeter and Terahertz Waves, 2011

A Microstrip Antenna Array for Indoor Wireless Dynamic Environments

IEEE Transactions on Antennas and Propagation, 2009

Analysis of Aperture Coupled Microstrip Antenna with Circular Polarization Diversity

Wireless Personal Communications, 2011

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Circular polarisation diversity with small size microstrip antenna

International Journal of Electronics, 2009

Satellite and ground data rainfall characterization in Malaysia

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Analysis of Rain Attenuation Models for South East Asia Countries

This paper presents an analysis of experimental data compared with existing rain attenuation pred... more This paper presents an analysis of experimental data compared with existing rain attenuation prediction models, namely, the Yamada, R&K, Crane, DAH and ITU models, which have been previously used in satellite communication systems. The experimental data were measured at the Universiti Sains Malaysia, Penang in the northern region of Peninsular Malaysia from 2007 to 2009 by receiving a Ku-band signal from the satellite SuperBird-C (geostationary at 144 °E). Data from Nigeria, Kenya, Indonesia, and PNG were obtained from the respective countries' researchers. The DAH and ITU models were recommended as the most suitable models. The recommendation was made based on the model's good performance compared with the measured data from the selected tropical countries.

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