Zachariah C. Alex

Printed Dipole Antenna With Band Rejection Characteristics for UWB Applications

This letter presents the design and performance measures of a printed dipole antenna with band rejection characteristics for ultrawideband (UWB) applications. The proposed antenna operates in the frequency range 3.65615.64 GHz with impedance bandwidth of 11.027 GHz and maximum gain of 6.046 dBi. It consists of five dipole strips of different resonant length combined orthogonally for effective signal reception. Inverted L-shaped slots were introduced in the ground plane for WLAN band rejection. The band rejection is from 5.066.012 GHz. The radiation pattern is nearly omnidirectional in both the elevation and azimuthal plane due to the orthogonal configuration of the dipole strips. The consistency of the radiation pattern exists within the operating band. The performance of the proposed antenna is confirmed by simulation and experimental method.

Neonatal brain MRI segmentation

This review paper focuses on the neonatal brain segmentation algorithms in the literature. It provides an overview of clinical magnetic resonance imaging (MRI) of the newborn brain and the challenges in automated tissue classification of neonatal brain MRI. It presents a complete survey of the existing segmentation methods and their salient features. The different approaches are categorized into intracranial and brain tissue segmentation algorithms based on their level of tissue classification. Further, the brain tissue segmentation techniques are grouped based on their atlas usage into atlas-based, augmented atlas-based and atlas-free methods. In addition, the research gaps and lacunae in literature are also identified.

Design and analysis of fractal antenna for UWB applications

This paper presents the design and analysis of fractal antenna that contributes ultra wide band characteristics. Fractal technique is adopted to improve radiation characteristics of the antenna. The impedance bandwidth of the proposed fractal antenna is 9.4 GHz ranging from 3.2GHz to 12.6 GHz with maximum gain of 6.2dB and efficiency of 98.66%. Analysis of antenna is done using CST Microwave Studio.

Design and development of non invasive glucose measurement system

One of the biggest health challenges of 21st century is diabetics due to its exponential increase in the diabetics patients in the age group of 20–79 years. To prevent the complication due to diabetics it is essential to monitor the blood glucose level continuously. Most of the regular glucose measurement systems are invasive in nature. Invasive methods cause pain, time consumption, high cost and potential risk of spreading infection diseases. Therefore there is a great demand to have reliable cost effective and comfortable non invasive system for the detection of blood glucose level continuously. The proposed method is based on the direct effect of glucose on the scattering properties of the organ. Glucose decreases the mismatch in refractive index between scatterers and their surrounding media, leading to a smaller scattering coefficient and, consequently, a shorter optical path. The reduction in scattering is due to an increase in glucose concentration. As a result, with the growing concentration of glucose, fewer photons are absorbed and the light intensity increases. In the present work, we have used PPG technique. An algorithm was developed from the PPG data for monitoring blood glucose. The result obtained from this technique was compared with ARKRAY, Glucocard tm01-mini and found good agreement.

A multi-fractal antenna for WLAN and WiMAX application

This paper presents a multi-fractal antenna operating in ultra wide band range for WLAN and WiMAX applications. The novel idea of multi-fractal geometry is introduced into the conventional triangular patch antenna with microstrip feed. The addition of Koch and Sierpinski fractal techniques gives rise to better impedance bandwidth and return loss characteristics. The proposed antenna exhibits resonant frequency at 5.48 GHz with a return loss of -31.9dB to satisfy the band specifications for wireless LAN applications IEEE802.11a (5.15-5.35 GHz, 5.725-5.875 GHz) and WiMAX application at 5GHz (5.25-5.85 GHz). It is found that the antenna exhibits omni-directional radiation pattern in H plane with a maximum gain of 3.5dB. The antenna exhibits a stable radiation pattern throughout the operating frequency range of 4.68-6.43 GHz. The antenna covers the upper and lower bands of WLAN operating frequencies. The simulation was performed in High Frequency Structure Simulator.

Design and analysis of a multi-fractal antenna for UWB application

This paper presents a Koch-like sided Sierpinski multi-fractal antenna for ultra wide band applications. The fractal techniques such as the Koch and Sierpinski Fractal techniques are been introduced into the conventional triangular patch antenna with microstrip feed to obtain better return loss and impedance bandwidth characteristics. The simulation was performed in High Frequency Structure Simulator (HFSS 13). The antenna parameters such as resonant frequency, return loss, radiation pattern and surface current distribution are simulated and discussed in this paper.

Design of meander line wearable antenna

A dual band meander line wearable antenna is designed at the operating frequencies of 406 MHz and 850 MHz. Textile fabric materials were used as the antenna substrate and copper is used as radiating element. Four different types of antenna substrates were put into study. SAR (specific absorption rate) is calculated for the designed antenna using the human body model from MRI and RT scan images. The calculated SAR falls well within the values prescribed by the standards.

Response Time Analysis of Messages in Controller Area Network: A Review

This paper reviews the research work done on the response time analysis of messages in controller area network (CAN) from the time CAN specification was submitted for standardization (1990) and became a standard (1993) up to the present (2012). Such research includes the worst-case response time analysis which is deterministic and probabilistic response time analysis which is stochastic. A detailed view on both types of analyses is presented here. In addition to these analyses, there has been research on statistical analysis of controller area network message response times.

Development of low cost automatic wheelchair controlled by oral commands using standalone controlling system

Development of automatic voice activated low cost wheelchair using intelligent standalone controlling system and Interfaces (Embedded LabVIEW and Compact Reconfigurable Input/Output FPGA Card-cRIO-9074) for physically impaired people is presented in this paper. Various interfaces to control the powered wheelchair were proposed in the past since the voice is the most natural communication ways for person so our study pays more attention to speech recognition. The voice commands produced by the user are captured and processed by the intelligent system. The system is integrated with Ultrasonic sensor and IR sensor for obstacle detection and path finding.

Design of a high gain low noise amplifier for wireless applications

This paper presents the design of a high gain low noise amplifier operating in a bandwidth of .5014 GHz for wireless applications. High gain of 16.17dB is achieved at a frequency of 4 GHz. The Low noise amplifier is an electronic amplifier used to amplify possibly very weak signals. Its mostly placed at the front-end of a radio receiver circuit so that the effect of noise from subsequent stages of the receiver chain is reduced by the gain of the LNA. The transistor used here for the design of LNA is GaAs FET N76000. The high gain low noise amplifier is designed by using AWR microwave office version.