Zachariah c alex - Academia.edu (original) (raw)

Papers by Zachariah c alex

Nanotechnology in Electronics

2016 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC), 2016

This paper describes an automatic technique to segment the ventricles from brain MRI of young chi... more This paper describes an automatic technique to segment the ventricles from brain MRI of young children. The segmentation approach involves skull stripping, extraction of the total cerebrospinal fluid (CSF), isolation of extra-cerebral CSF, removal of CSF in the sulci and fissures and final ventricle segmentation. The segmentation achieves a mean Dice ratio of 0.9246, sensitivity of 0.9363 and specificity of 0.9988. The novelty of the method is as follows: (1) it is completely devoid of brain atlases, templates and spatial priors; (2) it requires no prior training or human involvement.

2021 Innovations in Power and Advanced Computing Technologies (i-PACT), 2021

Surveillance or monitoring is always a major concern and challenge for security endpoints and now... more Surveillance or monitoring is always a major concern and challenge for security endpoints and nowadays with advancement of AI technology, the security surveillance can be achieved. Monitoring is the starting process of any security challenges. Public places like Restaurants and certain more viable places like banks, market, ATMs are in need of such system. However, constant manual monitoring using security cameras may miss abnormal cues. This paper illustrates the semi-automize system that is used for security monitoring. It processes various classes and CNN techniques that are used for implementation of Human Irregular Activity Detection Based on Posture and Behavioral Analysis (HIADPBA). The proposed methodology overcomes the uncertainty of the problems during the detection of activity. The knowledge base of this system contains real time data in conjunction with real life security. Surveillance data thereby increase the efficiency and accuracy of the detection of abnormal behavior.

2021 Innovations in Power and Advanced Computing Technologies (i-PACT), 2021

The present covid-19 pandemic necessitates the need for a cost effective and efficient remote hea... more The present covid-19 pandemic necessitates the need for a cost effective and efficient remote health monitoring mechanisms for the collection, transmission, evaluation, and communication of patient health data from electronic devices since many find it difficult to go for regular medical checkup due to safety concerns. Therefore, we require a remote health monitoring system that can monitor different body parameters and transmit it to a health care provider in a remote location. This paper describes the design and development of a remote health monitoring system capable of measuring ECG, Heart rate and SpO2 using AD8232, MAX30100 or MAX30102 and transfer this information to physicians using IoT. The ESP32 module is used to establish the IoT connectivity and share the vital information to medical practitioners for real-time analysis through a smartphone or Tab. In the present work, Blynk IoT cloud platform is used to communicate with hardware and software. The size of the designed PCB board is less than 60mm x 60 mm, therefore the size and weight of the device are very small and able to attach on the patient's cloth or in the body with the help of a Velcro belt. This helps the patient to easily carry the device without any discomfort.

Wireless Communication, 2010

The paper presents the design of ultra wideband antenna for wireless applications operating in th... more The paper presents the design of ultra wideband antenna for wireless applications operating in the frequency range 4.816 GHz to 11.08 GHz with good radiation performance. The designed UWB antenna consists of three strips resonating at different frequencies and a microstrip feed line on one side of the FR4 substrate and partial ground plane on the other side. The impedance bandwidth of the antenna for VSWR ≤ 2 is 6.262 GHz with the maximum gain of 2.247 dBi. The radiation pattern in the elevation plane is figure of eight with beam width of 740 and in azimuthal plane it is Omni directional. The consistency of the pattern exists within the operating bandwidth. The transverse dimension of the antenna is 10 x 10.4 mm2 excluding the feed line. The designed antenna was simulated using IE3D software and tested using Network Analyzer. The proposed UWB antenna can be integrated with hand held devices and consumer Electronic Equipment for short range applications due to its compact nature.

2017 International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT), 2017

This thesis reports the modified design of Sierpinski fractal antenna with a ring structure for U... more This thesis reports the modified design of Sierpinski fractal antenna with a ring structure for UWB applications. The fractal system is a method to miniaturize the antenna dimension to enhance its radiation and broadband properties. Due to the self-similarity property possessed by the fractal structure it has the multiband behavior. The proposed modified antenna with ring structure operates in the frequency range of 4.06 GHz to 9.13 GHz. The introduction of ring structure improves the bandwidth of the antenna. The proposed antenna developed two bands with the resonant frequencies of 4.76 GHz and 8.6 GHz. The each band operates with a return loss of −51db and −58.37db respectively. The design and performance analysis of the proposed antenna was done with CST Microwave Studio software.

International journal of engineering and technology, 2015

Conventional angle sensors can measure only 360°,but passenger car steering wheel turns through +... more Conventional angle sensors can measure only 360°,but passenger car steering wheel turns through +/-720 (a total of 4 complete turns). In this paper we describe iGMR based steering wheel angle sensor implementation which can be used as a rotation sensor to measure +/720°. KeywordSteering Wheel Angle Sensor, IGMR, Angle Sensor, GMR.

Advances in systems science and applications, 2016

Modeling and simulation plays vital role in the Micro Electro Mechanical Systems (MEMS) field. Op... more Modeling and simulation plays vital role in the Micro Electro Mechanical Systems (MEMS) field. Optical MEMS comprise of three domains namely optical, electrical and mechanical. The existing MEMS software for modeling is very expensive. This cost of modeling software increases the design and development of optical MEMS sensors. This paper proposes the design and development of a novel optical read out mechanism. This mechanism is used to measure the Maximum stress applied on the cantilever and its corresponding deflection of the cantilever. The experiments have been carried out using Ptolemy II software for design and Simulation of MEMS optical sensors. Laser Actor, a Photo detector and Force Actor have been created using Ptolemy II. COMSOL software has been used to model cantilever. A comparative study has been done for cantilever with three modes of Eigen frequencies using COMSOL. The experimental result shows that the Parylene optical MEMS force sensor can sense less range of stre...

Materials Today: Proceedings, 2018

Significant progress on the use of MEMS cantilever sensors to detect the various diseases has sur... more Significant progress on the use of MEMS cantilever sensors to detect the various diseases has surveyed. The Cantilever made in the micrometer size provides an opening to develop a highly sensitive sensor. It detects the biological molecules, chemicals, diseases and explosives. MEMS cantilevers can be produced in abundance at low cost with the material like Silicon, Silicon Nitride and Polymers. This paper has summarized various cantilevers for different diseases into a tabular form. This will enable the researchers to pick up genuine cantilever for right disease by choosing different materials, size and shape. And also it addresses various read out techniques used to detect the different diseases.

International Journal of Automation and Computing, 2018

The aim of this work is to develop an improved region based active contour and dynamic programmin... more The aim of this work is to develop an improved region based active contour and dynamic programming based method for accurate segmentation of left ventricle (LV) from multi-slice cine short axis cardiac magnetic resonance (MR) images. Intensity inhomogeneity and weak object boundaries present in MR images hinder the segmentation accuracy. The proposed active contour model driven by a local Gaussian distribution fitting (LGDF) energy and an auxiliary global intensity fitting energy improves the accuracy of endocardial boundary detection. The weightage of the global energy fitting term is dynamically adjusted using a spatially varying weight function. Dynamic programming scheme proposed for the segmentation of epicardium considers the myocardium probability map and a distance weighted edge map in the cost matrix. Radial distance weighted technique and conical geometry are employed for segmenting the basal slices with left ventricle outflow tract (LVOT) and most apical slices. The proposed method is validated on a public dataset comprising 45 subjects from medical image computing and computer assisted interventions (MICCAI) 2009 segmentation challenge. The average percentage of good endocardial and epicardial contours detected is about 99%, average perpendicular distance of the detected good contours from the manual reference contours is 1.95 mm, and the dice similarity coefficient between the detected contours and the reference contours is 0.91. Correlation coefficient and the coefficient of determination between the ejection fraction measurements from manual segmentation and the automated method are respectively 0.978 1 and 0.956 7, for LV mass these values are 0.924 9 and 0.855 4. Statistical analysis of the results reveals a good agreement between the clinical parameters determined manually and those estimated using the automated method.

Indian Journal of Science and Technology, 2016

2014 IEEE International Conference on Computational Intelligence and Computing Research, 2014

The automated tissue classification of pediatric brain magnetic resonance images, specially prope... more The automated tissue classification of pediatric brain magnetic resonance images, specially proper segmentation of myelinated white matter, is a highly challenging task. The proposed approach first extracts the brain tissue, followed by a precise delineation of the myelinated component based on Tsallis entropy segmentation. Unlike most of the currently available algorithms, the proposed technique is totally atlas-free. Qualitative validation shows that the obtained segmentation results correspond well to those of manual segmentation.

Computers in Biology and Medicine, 2015

This review paper focuses on the neonatal brain segmentation algorithms in the literature. It pro... more 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 atlasbased, augmented atlas-based and atlas-free methods. In addition, the research gaps and lacunae in literature are also identified.

2015 2nd International Conference on Electronics and Communication Systems (ICECS), 2015

Design and performance measures of a printed multi strip monopole antenna for ultra-wideband appl... more Design and performance measures of a printed multi strip monopole antenna for ultra-wideband application are presented. The proposed antenna consist of six quarter wavelength strips of different resonating frequency combined in a manner to provide wideband width. It operates in the frequency range 2.51~10.61GHz with impedance bandwidth of 8.1 GHz. The radiation pattern is nearly Omni directional in the Azimuthal plane and bidirectional in the elevation plane and the consistency of the radiation pattern exist for almost for all frequency in the operating band.

2014 International Conference on Green Computing Communication and Electrical Engineering (ICGCCEE), 2014

A multi-fractal monopole antenna for Ultra wide band applications is presented in this paper. The... more A multi-fractal monopole antenna for Ultra wide band applications is presented in this paper. The proposed antenna consists of a combination of Koch and Sierpinski fractals within a ring. Use of multi-fractal technique leads to improved bandwidth, radiation efficiency and reduced size. The proposed antenna size is 19.5*19.5*1 mm 3 which operates over a frequency range of 4.2 to 10.3 GHz. Radiation pattern of the proposed antenna is stable over the operating range.

2013 IEEE CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGIES, 2013

This paper presents the design of a high gain low noise amplifier operating in a bandwidth of .50... more 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.

2013 IEEE CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGIES, 2013

This paper presents a multi-fractal antenna operating in ultra wide band range for WLAN and WiMAX... more 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.

INTERNATIONAL CONFERENCE ON SMART STRUCTURES AND SYSTEMS - ICSSS'13, 2013

Breast cancer affects many women and early detection is important. The microwave imaging techniqu... more Breast cancer affects many women and early detection is important. The microwave imaging technique can play a vital role in the detection of breast tumor than X-ray mammography and other techniques. The basis of the microwave imaging technique for breast cancer detection and location is the significant contrast in the scattered electromagnetic signals that depends on the dielectric properties of normal and malignant tissues at microwave frequencies. Malignant tissues exhibit higher dielectric properties than normal breast tissues, especially at high frequencies. We have conducted a simulation study to find out the resolution of the microwave imaging using FDTD technique. In this paper, a Finite Difference Time Domain method is applied to investigate the presence and location of the buried object in a phantom material. The investigation considers a phantom formed by a spherical container filled with material whose permittivity and conductivity are similar to those of normal and abnormal tissues. The study shows that the E field variation in different dielectric mediums can be used for the detection of abnormality.

2014 International Conference on Green Computing Communication and Electrical Engineering (ICGCCEE), 2014

A Band pass filter which operates in the ultra wide band (UWB) range is designed and implemented.... more A Band pass filter which operates in the ultra wide band (UWB) range is designed and implemented. The proposed filter consists of two Interdigital coupled lines at the terminal end and three circular shaped electromagnetic band gap structures (EBG) at the centre of filter configuration. The Circular shaped EBG structures act as a multimode resonator (MMR) which is used to tune the frequency ranges of filters as well as to improve the return loss characteristics of filters. The bandwidth of proposed filter is 11.88 GHz (3.68-15.56 GHz) which covers the entire UWB range.

Microwave and Optical Technology Letters, 2012

laser driver current. A schematic of the experimental setup is shown in Figure 5. 3.2. Measuremen... more laser driver current. A schematic of the experimental setup is shown in Figure 5. 3.2. Measurements Before measuring the MOFRR, it is necessary to perform the VNA calibration, which is realized through the measurement of the optical link without the MOFRR. Then, the MOFRR is inserted, and its bandpass comb response is measured. Any problem on the bandpass filter shape is immediately visible in this experiment. Figure 6 shows an example of such a measurement performed on our three-loop fiber resonator in the X-band. The transmission characteristics of realized MOFRR filter have steep roll-off and flattened bandpass. The measured IL is <3 dB, the BW is around 180 MHz at 8.8 GHz center frequency and the ER is higher than 20 dB. So, the computed power coupling factors of our modeling of MOFRR with fixed values for L and N are consistent between the experimental response and the design specifications of the bandpass filter. Only the measured ILs are higher than the desired performances. This is may be due to the splice losses values realized with automatic splicing tools, that could be higher than 0.01 dB. The practical consequence will be a slightly higher IL figure. If the splice loss for each fiber loop is equal to 0.03 dB in the corresponding transfer function by retro-simulation, we can see on the Figure 6 that the measured filter characteristics are very close to the one obtained from the modeling. As the application in microwave systems require efficient out-of-bound rejection, and high transmission/ rejection contrast, it will be interesting to increase the number of fiber rings to obtain an ER higher than 80 dB.

Nanotechnology in Electronics

2016 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC), 2016

This paper describes an automatic technique to segment the ventricles from brain MRI of young chi... more This paper describes an automatic technique to segment the ventricles from brain MRI of young children. The segmentation approach involves skull stripping, extraction of the total cerebrospinal fluid (CSF), isolation of extra-cerebral CSF, removal of CSF in the sulci and fissures and final ventricle segmentation. The segmentation achieves a mean Dice ratio of 0.9246, sensitivity of 0.9363 and specificity of 0.9988. The novelty of the method is as follows: (1) it is completely devoid of brain atlases, templates and spatial priors; (2) it requires no prior training or human involvement.

2021 Innovations in Power and Advanced Computing Technologies (i-PACT), 2021

Surveillance or monitoring is always a major concern and challenge for security endpoints and now... more Surveillance or monitoring is always a major concern and challenge for security endpoints and nowadays with advancement of AI technology, the security surveillance can be achieved. Monitoring is the starting process of any security challenges. Public places like Restaurants and certain more viable places like banks, market, ATMs are in need of such system. However, constant manual monitoring using security cameras may miss abnormal cues. This paper illustrates the semi-automize system that is used for security monitoring. It processes various classes and CNN techniques that are used for implementation of Human Irregular Activity Detection Based on Posture and Behavioral Analysis (HIADPBA). The proposed methodology overcomes the uncertainty of the problems during the detection of activity. The knowledge base of this system contains real time data in conjunction with real life security. Surveillance data thereby increase the efficiency and accuracy of the detection of abnormal behavior.

2021 Innovations in Power and Advanced Computing Technologies (i-PACT), 2021

The present covid-19 pandemic necessitates the need for a cost effective and efficient remote hea... more The present covid-19 pandemic necessitates the need for a cost effective and efficient remote health monitoring mechanisms for the collection, transmission, evaluation, and communication of patient health data from electronic devices since many find it difficult to go for regular medical checkup due to safety concerns. Therefore, we require a remote health monitoring system that can monitor different body parameters and transmit it to a health care provider in a remote location. This paper describes the design and development of a remote health monitoring system capable of measuring ECG, Heart rate and SpO2 using AD8232, MAX30100 or MAX30102 and transfer this information to physicians using IoT. The ESP32 module is used to establish the IoT connectivity and share the vital information to medical practitioners for real-time analysis through a smartphone or Tab. In the present work, Blynk IoT cloud platform is used to communicate with hardware and software. The size of the designed PCB board is less than 60mm x 60 mm, therefore the size and weight of the device are very small and able to attach on the patient's cloth or in the body with the help of a Velcro belt. This helps the patient to easily carry the device without any discomfort.

Wireless Communication, 2010

The paper presents the design of ultra wideband antenna for wireless applications operating in th... more The paper presents the design of ultra wideband antenna for wireless applications operating in the frequency range 4.816 GHz to 11.08 GHz with good radiation performance. The designed UWB antenna consists of three strips resonating at different frequencies and a microstrip feed line on one side of the FR4 substrate and partial ground plane on the other side. The impedance bandwidth of the antenna for VSWR ≤ 2 is 6.262 GHz with the maximum gain of 2.247 dBi. The radiation pattern in the elevation plane is figure of eight with beam width of 740 and in azimuthal plane it is Omni directional. The consistency of the pattern exists within the operating bandwidth. The transverse dimension of the antenna is 10 x 10.4 mm2 excluding the feed line. The designed antenna was simulated using IE3D software and tested using Network Analyzer. The proposed UWB antenna can be integrated with hand held devices and consumer Electronic Equipment for short range applications due to its compact nature.

2017 International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT), 2017

This thesis reports the modified design of Sierpinski fractal antenna with a ring structure for U... more This thesis reports the modified design of Sierpinski fractal antenna with a ring structure for UWB applications. The fractal system is a method to miniaturize the antenna dimension to enhance its radiation and broadband properties. Due to the self-similarity property possessed by the fractal structure it has the multiband behavior. The proposed modified antenna with ring structure operates in the frequency range of 4.06 GHz to 9.13 GHz. The introduction of ring structure improves the bandwidth of the antenna. The proposed antenna developed two bands with the resonant frequencies of 4.76 GHz and 8.6 GHz. The each band operates with a return loss of −51db and −58.37db respectively. The design and performance analysis of the proposed antenna was done with CST Microwave Studio software.

International journal of engineering and technology, 2015

Conventional angle sensors can measure only 360°,but passenger car steering wheel turns through +... more Conventional angle sensors can measure only 360°,but passenger car steering wheel turns through +/-720 (a total of 4 complete turns). In this paper we describe iGMR based steering wheel angle sensor implementation which can be used as a rotation sensor to measure +/720°. KeywordSteering Wheel Angle Sensor, IGMR, Angle Sensor, GMR.

Advances in systems science and applications, 2016

Modeling and simulation plays vital role in the Micro Electro Mechanical Systems (MEMS) field. Op... more Modeling and simulation plays vital role in the Micro Electro Mechanical Systems (MEMS) field. Optical MEMS comprise of three domains namely optical, electrical and mechanical. The existing MEMS software for modeling is very expensive. This cost of modeling software increases the design and development of optical MEMS sensors. This paper proposes the design and development of a novel optical read out mechanism. This mechanism is used to measure the Maximum stress applied on the cantilever and its corresponding deflection of the cantilever. The experiments have been carried out using Ptolemy II software for design and Simulation of MEMS optical sensors. Laser Actor, a Photo detector and Force Actor have been created using Ptolemy II. COMSOL software has been used to model cantilever. A comparative study has been done for cantilever with three modes of Eigen frequencies using COMSOL. The experimental result shows that the Parylene optical MEMS force sensor can sense less range of stre...

Materials Today: Proceedings, 2018

Significant progress on the use of MEMS cantilever sensors to detect the various diseases has sur... more Significant progress on the use of MEMS cantilever sensors to detect the various diseases has surveyed. The Cantilever made in the micrometer size provides an opening to develop a highly sensitive sensor. It detects the biological molecules, chemicals, diseases and explosives. MEMS cantilevers can be produced in abundance at low cost with the material like Silicon, Silicon Nitride and Polymers. This paper has summarized various cantilevers for different diseases into a tabular form. This will enable the researchers to pick up genuine cantilever for right disease by choosing different materials, size and shape. And also it addresses various read out techniques used to detect the different diseases.

International Journal of Automation and Computing, 2018

The aim of this work is to develop an improved region based active contour and dynamic programmin... more The aim of this work is to develop an improved region based active contour and dynamic programming based method for accurate segmentation of left ventricle (LV) from multi-slice cine short axis cardiac magnetic resonance (MR) images. Intensity inhomogeneity and weak object boundaries present in MR images hinder the segmentation accuracy. The proposed active contour model driven by a local Gaussian distribution fitting (LGDF) energy and an auxiliary global intensity fitting energy improves the accuracy of endocardial boundary detection. The weightage of the global energy fitting term is dynamically adjusted using a spatially varying weight function. Dynamic programming scheme proposed for the segmentation of epicardium considers the myocardium probability map and a distance weighted edge map in the cost matrix. Radial distance weighted technique and conical geometry are employed for segmenting the basal slices with left ventricle outflow tract (LVOT) and most apical slices. The proposed method is validated on a public dataset comprising 45 subjects from medical image computing and computer assisted interventions (MICCAI) 2009 segmentation challenge. The average percentage of good endocardial and epicardial contours detected is about 99%, average perpendicular distance of the detected good contours from the manual reference contours is 1.95 mm, and the dice similarity coefficient between the detected contours and the reference contours is 0.91. Correlation coefficient and the coefficient of determination between the ejection fraction measurements from manual segmentation and the automated method are respectively 0.978 1 and 0.956 7, for LV mass these values are 0.924 9 and 0.855 4. Statistical analysis of the results reveals a good agreement between the clinical parameters determined manually and those estimated using the automated method.

Indian Journal of Science and Technology, 2016

2014 IEEE International Conference on Computational Intelligence and Computing Research, 2014

The automated tissue classification of pediatric brain magnetic resonance images, specially prope... more The automated tissue classification of pediatric brain magnetic resonance images, specially proper segmentation of myelinated white matter, is a highly challenging task. The proposed approach first extracts the brain tissue, followed by a precise delineation of the myelinated component based on Tsallis entropy segmentation. Unlike most of the currently available algorithms, the proposed technique is totally atlas-free. Qualitative validation shows that the obtained segmentation results correspond well to those of manual segmentation.

Computers in Biology and Medicine, 2015

This review paper focuses on the neonatal brain segmentation algorithms in the literature. It pro... more 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 atlasbased, augmented atlas-based and atlas-free methods. In addition, the research gaps and lacunae in literature are also identified.

2015 2nd International Conference on Electronics and Communication Systems (ICECS), 2015

Design and performance measures of a printed multi strip monopole antenna for ultra-wideband appl... more Design and performance measures of a printed multi strip monopole antenna for ultra-wideband application are presented. The proposed antenna consist of six quarter wavelength strips of different resonating frequency combined in a manner to provide wideband width. It operates in the frequency range 2.51~10.61GHz with impedance bandwidth of 8.1 GHz. The radiation pattern is nearly Omni directional in the Azimuthal plane and bidirectional in the elevation plane and the consistency of the radiation pattern exist for almost for all frequency in the operating band.

2014 International Conference on Green Computing Communication and Electrical Engineering (ICGCCEE), 2014

A multi-fractal monopole antenna for Ultra wide band applications is presented in this paper. The... more A multi-fractal monopole antenna for Ultra wide band applications is presented in this paper. The proposed antenna consists of a combination of Koch and Sierpinski fractals within a ring. Use of multi-fractal technique leads to improved bandwidth, radiation efficiency and reduced size. The proposed antenna size is 19.5*19.5*1 mm 3 which operates over a frequency range of 4.2 to 10.3 GHz. Radiation pattern of the proposed antenna is stable over the operating range.

2013 IEEE CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGIES, 2013

This paper presents the design of a high gain low noise amplifier operating in a bandwidth of .50... more 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.

2013 IEEE CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGIES, 2013

This paper presents a multi-fractal antenna operating in ultra wide band range for WLAN and WiMAX... more 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.

INTERNATIONAL CONFERENCE ON SMART STRUCTURES AND SYSTEMS - ICSSS'13, 2013

Breast cancer affects many women and early detection is important. The microwave imaging techniqu... more Breast cancer affects many women and early detection is important. The microwave imaging technique can play a vital role in the detection of breast tumor than X-ray mammography and other techniques. The basis of the microwave imaging technique for breast cancer detection and location is the significant contrast in the scattered electromagnetic signals that depends on the dielectric properties of normal and malignant tissues at microwave frequencies. Malignant tissues exhibit higher dielectric properties than normal breast tissues, especially at high frequencies. We have conducted a simulation study to find out the resolution of the microwave imaging using FDTD technique. In this paper, a Finite Difference Time Domain method is applied to investigate the presence and location of the buried object in a phantom material. The investigation considers a phantom formed by a spherical container filled with material whose permittivity and conductivity are similar to those of normal and abnormal tissues. The study shows that the E field variation in different dielectric mediums can be used for the detection of abnormality.

2014 International Conference on Green Computing Communication and Electrical Engineering (ICGCCEE), 2014

A Band pass filter which operates in the ultra wide band (UWB) range is designed and implemented.... more A Band pass filter which operates in the ultra wide band (UWB) range is designed and implemented. The proposed filter consists of two Interdigital coupled lines at the terminal end and three circular shaped electromagnetic band gap structures (EBG) at the centre of filter configuration. The Circular shaped EBG structures act as a multimode resonator (MMR) which is used to tune the frequency ranges of filters as well as to improve the return loss characteristics of filters. The bandwidth of proposed filter is 11.88 GHz (3.68-15.56 GHz) which covers the entire UWB range.

Microwave and Optical Technology Letters, 2012

laser driver current. A schematic of the experimental setup is shown in Figure 5. 3.2. Measuremen... more laser driver current. A schematic of the experimental setup is shown in Figure 5. 3.2. Measurements Before measuring the MOFRR, it is necessary to perform the VNA calibration, which is realized through the measurement of the optical link without the MOFRR. Then, the MOFRR is inserted, and its bandpass comb response is measured. Any problem on the bandpass filter shape is immediately visible in this experiment. Figure 6 shows an example of such a measurement performed on our three-loop fiber resonator in the X-band. The transmission characteristics of realized MOFRR filter have steep roll-off and flattened bandpass. The measured IL is <3 dB, the BW is around 180 MHz at 8.8 GHz center frequency and the ER is higher than 20 dB. So, the computed power coupling factors of our modeling of MOFRR with fixed values for L and N are consistent between the experimental response and the design specifications of the bandpass filter. Only the measured ILs are higher than the desired performances. This is may be due to the splice losses values realized with automatic splicing tools, that could be higher than 0.01 dB. The practical consequence will be a slightly higher IL figure. If the splice loss for each fiber loop is equal to 0.03 dB in the corresponding transfer function by retro-simulation, we can see on the Figure 6 that the measured filter characteristics are very close to the one obtained from the modeling. As the application in microwave systems require efficient out-of-bound rejection, and high transmission/ rejection contrast, it will be interesting to increase the number of fiber rings to obtain an ER higher than 80 dB.