Muammar Mohamad Isa | Universiti Malaysia Perlis (UniMAP) (original) (raw)

Papers by Muammar Mohamad Isa

2019 6th International Conference on Space Science and Communication (IconSpace), 2019

In this paper, wearable textile antenna is presented for detecting breast cancer in early stages.... more In this paper, wearable textile antenna is presented for detecting breast cancer in early stages. The proposed antenna is designed and optimized using a 0.5 flexible cotton material substrate to operate at UWB with a wider frequency range of 3 GHz - 10.5 GHz. In this paper, the performance of the antenna is investigated in terms of reflection coefficients, gain and radiation patterns by bending the structure in several different degrees. A line slot is used at the ground level to enhance the antenna resonate performance overdesigned spectrum. Moreover, the antenna has good gain and efficiency over the bandwidth of 3.47 dBi and 92.3 % respectively.

Bulletin of Electrical Engineering and Informatics, 2019

This paper present the design of a circular patch microstrip antenna with enhancement in terms of... more This paper present the design of a circular patch microstrip antenna with enhancement in terms of bandwidth and gain using a dielectric double negative (DNG) split ring metamaterial radome. This radome is positioned on top of the CP antenna operating from 5.2 GHz to 6.4 GHz. The metamaterial radome comprises of two alternate split rings of negative permittivity, permeability and refractive index. The circular microstrip antenna bandwidth of 430 MHz has been realized by the presence of DNG metamaterial radome compared to 220 MHz without the radome. The gain has been increased as well from 1.84 dBi to 3.87 dBi.

Bulletin of Electrical Engineering and Informatics, 2019

The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surf... more The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surface Mount Device (SMD) LPF with cutoff frequency at 700 MHz. Fabricated LPF is consisted of four PCB layers which components of SMD are soldered on the top layer. Another three layers is for grounding and shielding, power supply and grounding void. The four layers is crucial to avoid interference between components. The research has find out that the momentum simulation is definitely required to improve the signals response compared to a normal simulation by ADS software. The comparison between momentum simulated versus measured and normal simulated versus measured is 0.2 dB and 29 dB correspondingly. Such huge difference leads to conclusion that momentum simulation is saving time without having much struggles and efforts to get optimum readings. The Proposed SMD LPF has a very low insertion loss of 0.965dB with a transition region of 195 MHz which is good steepness to avoid any image fr...

AIP Conference Proceedings, 2020

This article presents the microwave imaging techniques in order to detect early lung cancer with ... more This article presents the microwave imaging techniques in order to detect early lung cancer with dielectric properties of normal and cancerous tissues which affect the propagation of the microwave signal. Identifying the contrast of dielectric properties of normal and cancerous lung tissues is significant in microwave imaging because it is used in reconstructing the image either in radar-based or tomographic imaging techniques. In microwave imaging measurement from past researchers are highlighted in order to identify the optimum distance of the antenna from the human thorax and the significant size of the tumour that can be detectable.

Procedia - Social and Behavioral Sciences, 2013

This paper discusses the current contributions of professional engineers (P.Es.) who have obtaine... more This paper discusses the current contributions of professional engineers (P.Es.) who have obtained their competency qualifications prior to assuming their new careers at the institutions of higher learning (IHLs). Recent surveys conducted by recruitment agencies show a wide gap between engineering graduates' abilities and employers' expectations. This gap simply means a longer learning curve for trainee engineers expected by employers. However, most importantly, it seems that employers have to take on the job to bridge the gap. Providing training means incurring costs and resources. There are many schemes provided by multinational company (MNC) however such schemes may not be options by small and medium enterprise (SME). Based on experience, discussion and observations, P.E.s contribute positively in the three core areas: 1) teaching and learning 2) research and publication and 3) industrial linkage.

AIP Conference Proceedings, 2018

In this paper, an amplifier circuit is designed using floating gate MOSFET (FGMOS). The technolog... more In this paper, an amplifier circuit is designed using floating gate MOSFET (FGMOS). The technology used in 0.13 μm and the circuit is simulated using Mentor Graphic software. The proposed amplifier is implemented with three inputs FGMOS at the programmable stage in order to obtain low threshold voltage, V th , which consequently produce a lower supply voltage and the power consumption. The simulations results demonstrate Vth of 0.486 V and the power dissipation is 73 mW for supply voltage of 1 V. This circuit design is also supplied with 1.8 V and 3.0 V as comparisons to define the lowest V th value which is produced by supply voltage 1.8 V: 0.380 V.

AIP Conference Proceedings, 2017

A unipolar two-terminal nanodevice, known as the self-switching diode (SSD), has recently been de... more A unipolar two-terminal nanodevice, known as the self-switching diode (SSD), has recently been demonstrated as a room-temperature rectifier at microwave and terahertz frequencies due to its nonlinear currentvoltage characteristic. The planar architecture of SSD not only makes the fabrication process of the device faster, simpler and at a lower cost when compared with other rectifying diodes, but also allows the use of various materials to realize and fabricate SSDs. This includes the utilization of 'green' materials such as organic and graphene thin films for environmental sustainability. This paper reviews the properties of current 'green' SSD rectifiers with respect to their operating frequencies and rectifying performances, including responsivity and noise-equivalent power of the devices, along with the applications.

2016 3rd International Conference on Electronic Design (ICED), 2016

A planar nanodevice, known as the self-switching diode (SSD) has been demonstrated to rectify ele... more A planar nanodevice, known as the self-switching diode (SSD) has been demonstrated to rectify electromagnetic signals at microwave and terahertz frequencies. This diode has a non-linear current-voltage (I-V) characteristic due to the structure of the device which consists of asymmetric nanochannel. To further explore the properties of SSD rectifiers, in this work, silicon-based SSDs with different dielectric materials that filled up the trenches of the devices were simulated using ATLAS device simulator under the temperature range of 250 K-500 K. The results showed that the rectification performance of the SSDs was deteriorated with increasing temperature for all dielectric materials which might be due to the thermal-activated electronic transport behavior of the devices.

2016 5th International Symposium on Next-Generation Electronics (ISNE), 2016

In the advancement of the Internet of Things (IoT) applications, widespread uses and applications... more In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cutoff frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for application in low-power devices.

Solid-State Electronics, 2016

We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as ... more We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as the self-switching diodes (SSDs). The large array was realized in a single lithography step without the need of interconnection layers, hence allowing for a simple and low-cost fabrication process. The SSD array was coupled with a narrowband dipole antenna with a resonant frequency of 890 MHz, to form a simple rectenna (rectifying antenna). The extrinsic voltage responsivity and noise-equivalent-power

Applied Mechanics and Materials, 2015

We report the development of two epilayers namely the baseline highly strained channel and enhanc... more We report the development of two epilayers namely the baseline highly strained channel and enhanced low gate leakage samples. The Hall data shows that the enhanced epilayer portraying higher sheet carrier concentration, but comparable carrier mobility in the 2-DEG layer, as compared to the baseline sample. The WinGreen simulation also conformed the enhanced epilayer advantages where wider Schottky barrier is observed and subsequently double carrier concentration is simulated in the channel. Both samples show low AuGe/Au Ohmic contact resistivity of approximately 0.16 Ω.mm. A tremendous advantage on 1 μm Schottky gate leakage is also recorded on enhanced epilayer where the leakage is more than seven times lower than that of the baseline sample. The resulted characteristics are much better than the reported submicron device, thus this device has find an important application in high-gain lossless transmission, especially in underwater optical communication system.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Bulletin of Electrical Engineering and Informatics, 2019

In the advancement of the Internet of Things (IoT) applications, widespread uses and applications... more In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cut-off frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for app...

Japanese Journal of Applied Physics, 2018

In this report, we proposed and simulated a new planar nonlinear rectifying device fabricated usi... more In this report, we proposed and simulated a new planar nonlinear rectifying device fabricated using InGaAs substrate and referred to as a planar barrier diode (PBD). Using an asymmetrical inverse-arrowhead-shaped structure between the electrodes, a nonuniform depletion region is developed, which creates a triangular energy barrier in the conducting channel. This barrier is voltage dependent and can be controlled by the applied voltage across the PBD, thus resulting in nonlinear diode-like current-voltage characteristics; thus it can be used as a rectifying device. The PBD's working principle is explained using thermionic emission theory. Furthermore, by varying the PBD's geometric design, the asymmetry of the current-voltage characteristics can be optimized to realize superior rectification performance. By employing the optimized structural parameters, the obtained cutoff frequency of the device was approximately 270 GHz with a curvature coefficient peak of 14 V %1 at a low DC bias voltage of 50 mV.

IEEE Access, 2019

The broadband five-port reflectometer (FPR) is proposed using a triple-ring based technique. The ... more The broadband five-port reflectometer (FPR) is proposed using a triple-ring based technique. The design introduces a tapering in the interring transmission lines (TLs), which provides additional degrees of freedom for optimization and contributes to increased bandwidth. The miniaturization strategy allows incorporating the third ring without significant size increase. In addition, a method for expressing the effective physical dimension of a planar symmetric FPR is also presented in an easily comprehensible way, which can be implemented for other symmetric planar junctions with more than four ports. The proposed design comprises three concentric rings with phase-shifting arrangements between the interring TLs and outer matching arm sections. Interring TLs are shifted by 36 • (half factorized value of the inter-port angular distance of 72 •) in three different optimizing steps. Tapered TLs have been used between two consecutive rings to achieve very wide bandwidth of at least 88% in simulations and at least 85% in measurements. Curved matching TLs are used in the final design, yielding a compact size of 0.397λ g × 0.377λ g with 43% reduction in length and 43% in width compared to its non-compact counterpart. Genetic algorithm and quasi-Newton algorithm are used in optimizing the final prototype for operation in the frequency band used for brain microwave imaging. The proposed FPR realized a fractional bandwidth of at least 85% (from 0.96 to 2.38 GHz) with a reflection coefficient below −20 dB and a −6 ± 1 dB transmission coefficient with the required phase shift of ±120 • between different ports. The measured results agree well with the simulation. Finally, the overall imaging system setup and image construction algorithm are presented and discussed for possible incorporation with this FPR for brain microwave imaging. INDEX TERMS Five-port reflectometer, microwave imaging.

2016 3rd International Conference on Electronic Design (ICED), 2016

This paper presents the design and optimisation of film bulk acoustic wave resonator (FBAR) using... more This paper presents the design and optimisation of film bulk acoustic wave resonator (FBAR) using nano electro mechanical systems (NEMS) technology in 10-20 GHz frequency band. The effect of thickness, width and length and damping factor of the FBAR are analysed. The air-gap FBAR are designed due its ability to achieve high quality (Q) factor in 10-20 GHz frequency band. The proposed designs achieve a constant electromechanical coupling coefficient for 10-20 GHz. Analysis shows the Q varies highly dependent on the damping factor. The results show that the proposed design achieves almost double the Q factor at 15 GHz and 20 GHz operation when compared to similar designs.

2016 3rd International Conference on Electronic Design (ICED), 2016

A homogeneous film of acid functionalized Carbon Nanotubes was deposited on the paper substrate u... more A homogeneous film of acid functionalized Carbon Nanotubes was deposited on the paper substrate using Langmuir-Blodgett technique. The palladium nanoparticles were dropped on the nanotubes network afterword for device enhancement. The sensitivity of the device towards hydrogen gas was tested at three temperatures; room temperature, 200 °C and 300 °C in atmospheric conditions. The results show that CNT network with Pd decorated has high sensing response up to 22 % recorded at room temperature.

MATEC Web of Conferences, 2016

Asian Pacific Journal of Cancer Prevention, 2012

Measurement of quality of life among prostate cancer patients helps the health care providers to ... more Measurement of quality of life among prostate cancer patients helps the health care providers to understand the impact of the disease in the patients' own perspective. The main aim of this study is to measure the quality of life among prostate cancer patients at University Malaya Medical Center (UMMC) and Universiti Kebangsaan Malaysia Medical Centre (UKMMC) and to ascertain the association factors for physical coefficient summary (PCS) and mental coefficient summary (MCS). A hospital based, cross sectional study using the Short Form-36 (SF-36) questionnaire was conducted over a period of 6 months. A total of 193 respondents were recruited. Their total quality of life score was 70.1±14.7 and the PCS score was lower compared to MCS. The factors associated for PCS were: age, living partner, renal problem, urinary problem of intermittency, dysuria and hematuria. Factors associated for MCS were: age, living partner, renal problem, presenting prostatic specific antigen and urinary problem of intermittency and dysuria. Our prostate cancer patients had moderate quality of life in the physical health components but their mental health was less affected.

2019 6th International Conference on Space Science and Communication (IconSpace), 2019

In this paper, wearable textile antenna is presented for detecting breast cancer in early stages.... more In this paper, wearable textile antenna is presented for detecting breast cancer in early stages. The proposed antenna is designed and optimized using a 0.5 flexible cotton material substrate to operate at UWB with a wider frequency range of 3 GHz - 10.5 GHz. In this paper, the performance of the antenna is investigated in terms of reflection coefficients, gain and radiation patterns by bending the structure in several different degrees. A line slot is used at the ground level to enhance the antenna resonate performance overdesigned spectrum. Moreover, the antenna has good gain and efficiency over the bandwidth of 3.47 dBi and 92.3 % respectively.

Bulletin of Electrical Engineering and Informatics, 2019

This paper present the design of a circular patch microstrip antenna with enhancement in terms of... more This paper present the design of a circular patch microstrip antenna with enhancement in terms of bandwidth and gain using a dielectric double negative (DNG) split ring metamaterial radome. This radome is positioned on top of the CP antenna operating from 5.2 GHz to 6.4 GHz. The metamaterial radome comprises of two alternate split rings of negative permittivity, permeability and refractive index. The circular microstrip antenna bandwidth of 430 MHz has been realized by the presence of DNG metamaterial radome compared to 220 MHz without the radome. The gain has been increased as well from 1.84 dBi to 3.87 dBi.

Bulletin of Electrical Engineering and Informatics, 2019

The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surf... more The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surface Mount Device (SMD) LPF with cutoff frequency at 700 MHz. Fabricated LPF is consisted of four PCB layers which components of SMD are soldered on the top layer. Another three layers is for grounding and shielding, power supply and grounding void. The four layers is crucial to avoid interference between components. The research has find out that the momentum simulation is definitely required to improve the signals response compared to a normal simulation by ADS software. The comparison between momentum simulated versus measured and normal simulated versus measured is 0.2 dB and 29 dB correspondingly. Such huge difference leads to conclusion that momentum simulation is saving time without having much struggles and efforts to get optimum readings. The Proposed SMD LPF has a very low insertion loss of 0.965dB with a transition region of 195 MHz which is good steepness to avoid any image fr...

AIP Conference Proceedings, 2020

This article presents the microwave imaging techniques in order to detect early lung cancer with ... more This article presents the microwave imaging techniques in order to detect early lung cancer with dielectric properties of normal and cancerous tissues which affect the propagation of the microwave signal. Identifying the contrast of dielectric properties of normal and cancerous lung tissues is significant in microwave imaging because it is used in reconstructing the image either in radar-based or tomographic imaging techniques. In microwave imaging measurement from past researchers are highlighted in order to identify the optimum distance of the antenna from the human thorax and the significant size of the tumour that can be detectable.

Procedia - Social and Behavioral Sciences, 2013

This paper discusses the current contributions of professional engineers (P.Es.) who have obtaine... more This paper discusses the current contributions of professional engineers (P.Es.) who have obtained their competency qualifications prior to assuming their new careers at the institutions of higher learning (IHLs). Recent surveys conducted by recruitment agencies show a wide gap between engineering graduates' abilities and employers' expectations. This gap simply means a longer learning curve for trainee engineers expected by employers. However, most importantly, it seems that employers have to take on the job to bridge the gap. Providing training means incurring costs and resources. There are many schemes provided by multinational company (MNC) however such schemes may not be options by small and medium enterprise (SME). Based on experience, discussion and observations, P.E.s contribute positively in the three core areas: 1) teaching and learning 2) research and publication and 3) industrial linkage.

AIP Conference Proceedings, 2018

In this paper, an amplifier circuit is designed using floating gate MOSFET (FGMOS). The technolog... more In this paper, an amplifier circuit is designed using floating gate MOSFET (FGMOS). The technology used in 0.13 μm and the circuit is simulated using Mentor Graphic software. The proposed amplifier is implemented with three inputs FGMOS at the programmable stage in order to obtain low threshold voltage, V th , which consequently produce a lower supply voltage and the power consumption. The simulations results demonstrate Vth of 0.486 V and the power dissipation is 73 mW for supply voltage of 1 V. This circuit design is also supplied with 1.8 V and 3.0 V as comparisons to define the lowest V th value which is produced by supply voltage 1.8 V: 0.380 V.

AIP Conference Proceedings, 2017

A unipolar two-terminal nanodevice, known as the self-switching diode (SSD), has recently been de... more A unipolar two-terminal nanodevice, known as the self-switching diode (SSD), has recently been demonstrated as a room-temperature rectifier at microwave and terahertz frequencies due to its nonlinear currentvoltage characteristic. The planar architecture of SSD not only makes the fabrication process of the device faster, simpler and at a lower cost when compared with other rectifying diodes, but also allows the use of various materials to realize and fabricate SSDs. This includes the utilization of 'green' materials such as organic and graphene thin films for environmental sustainability. This paper reviews the properties of current 'green' SSD rectifiers with respect to their operating frequencies and rectifying performances, including responsivity and noise-equivalent power of the devices, along with the applications.

2016 3rd International Conference on Electronic Design (ICED), 2016

A planar nanodevice, known as the self-switching diode (SSD) has been demonstrated to rectify ele... more A planar nanodevice, known as the self-switching diode (SSD) has been demonstrated to rectify electromagnetic signals at microwave and terahertz frequencies. This diode has a non-linear current-voltage (I-V) characteristic due to the structure of the device which consists of asymmetric nanochannel. To further explore the properties of SSD rectifiers, in this work, silicon-based SSDs with different dielectric materials that filled up the trenches of the devices were simulated using ATLAS device simulator under the temperature range of 250 K-500 K. The results showed that the rectification performance of the SSDs was deteriorated with increasing temperature for all dielectric materials which might be due to the thermal-activated electronic transport behavior of the devices.

2016 5th International Symposium on Next-Generation Electronics (ISNE), 2016

In the advancement of the Internet of Things (IoT) applications, widespread uses and applications... more In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cutoff frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for application in low-power devices.

Solid-State Electronics, 2016

We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as ... more We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as the self-switching diodes (SSDs). The large array was realized in a single lithography step without the need of interconnection layers, hence allowing for a simple and low-cost fabrication process. The SSD array was coupled with a narrowband dipole antenna with a resonant frequency of 890 MHz, to form a simple rectenna (rectifying antenna). The extrinsic voltage responsivity and noise-equivalent-power

Applied Mechanics and Materials, 2015

We report the development of two epilayers namely the baseline highly strained channel and enhanc... more We report the development of two epilayers namely the baseline highly strained channel and enhanced low gate leakage samples. The Hall data shows that the enhanced epilayer portraying higher sheet carrier concentration, but comparable carrier mobility in the 2-DEG layer, as compared to the baseline sample. The WinGreen simulation also conformed the enhanced epilayer advantages where wider Schottky barrier is observed and subsequently double carrier concentration is simulated in the channel. Both samples show low AuGe/Au Ohmic contact resistivity of approximately 0.16 Ω.mm. A tremendous advantage on 1 μm Schottky gate leakage is also recorded on enhanced epilayer where the leakage is more than seven times lower than that of the baseline sample. The resulted characteristics are much better than the reported submicron device, thus this device has find an important application in high-gain lossless transmission, especially in underwater optical communication system.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Bulletin of Electrical Engineering and Informatics, 2019

In the advancement of the Internet of Things (IoT) applications, widespread uses and applications... more In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cut-off frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for app...

Japanese Journal of Applied Physics, 2018

In this report, we proposed and simulated a new planar nonlinear rectifying device fabricated usi... more In this report, we proposed and simulated a new planar nonlinear rectifying device fabricated using InGaAs substrate and referred to as a planar barrier diode (PBD). Using an asymmetrical inverse-arrowhead-shaped structure between the electrodes, a nonuniform depletion region is developed, which creates a triangular energy barrier in the conducting channel. This barrier is voltage dependent and can be controlled by the applied voltage across the PBD, thus resulting in nonlinear diode-like current-voltage characteristics; thus it can be used as a rectifying device. The PBD's working principle is explained using thermionic emission theory. Furthermore, by varying the PBD's geometric design, the asymmetry of the current-voltage characteristics can be optimized to realize superior rectification performance. By employing the optimized structural parameters, the obtained cutoff frequency of the device was approximately 270 GHz with a curvature coefficient peak of 14 V %1 at a low DC bias voltage of 50 mV.

IEEE Access, 2019

The broadband five-port reflectometer (FPR) is proposed using a triple-ring based technique. The ... more The broadband five-port reflectometer (FPR) is proposed using a triple-ring based technique. The design introduces a tapering in the interring transmission lines (TLs), which provides additional degrees of freedom for optimization and contributes to increased bandwidth. The miniaturization strategy allows incorporating the third ring without significant size increase. In addition, a method for expressing the effective physical dimension of a planar symmetric FPR is also presented in an easily comprehensible way, which can be implemented for other symmetric planar junctions with more than four ports. The proposed design comprises three concentric rings with phase-shifting arrangements between the interring TLs and outer matching arm sections. Interring TLs are shifted by 36 • (half factorized value of the inter-port angular distance of 72 •) in three different optimizing steps. Tapered TLs have been used between two consecutive rings to achieve very wide bandwidth of at least 88% in simulations and at least 85% in measurements. Curved matching TLs are used in the final design, yielding a compact size of 0.397λ g × 0.377λ g with 43% reduction in length and 43% in width compared to its non-compact counterpart. Genetic algorithm and quasi-Newton algorithm are used in optimizing the final prototype for operation in the frequency band used for brain microwave imaging. The proposed FPR realized a fractional bandwidth of at least 85% (from 0.96 to 2.38 GHz) with a reflection coefficient below −20 dB and a −6 ± 1 dB transmission coefficient with the required phase shift of ±120 • between different ports. The measured results agree well with the simulation. Finally, the overall imaging system setup and image construction algorithm are presented and discussed for possible incorporation with this FPR for brain microwave imaging. INDEX TERMS Five-port reflectometer, microwave imaging.

2016 3rd International Conference on Electronic Design (ICED), 2016

This paper presents the design and optimisation of film bulk acoustic wave resonator (FBAR) using... more This paper presents the design and optimisation of film bulk acoustic wave resonator (FBAR) using nano electro mechanical systems (NEMS) technology in 10-20 GHz frequency band. The effect of thickness, width and length and damping factor of the FBAR are analysed. The air-gap FBAR are designed due its ability to achieve high quality (Q) factor in 10-20 GHz frequency band. The proposed designs achieve a constant electromechanical coupling coefficient for 10-20 GHz. Analysis shows the Q varies highly dependent on the damping factor. The results show that the proposed design achieves almost double the Q factor at 15 GHz and 20 GHz operation when compared to similar designs.

2016 3rd International Conference on Electronic Design (ICED), 2016

A homogeneous film of acid functionalized Carbon Nanotubes was deposited on the paper substrate u... more A homogeneous film of acid functionalized Carbon Nanotubes was deposited on the paper substrate using Langmuir-Blodgett technique. The palladium nanoparticles were dropped on the nanotubes network afterword for device enhancement. The sensitivity of the device towards hydrogen gas was tested at three temperatures; room temperature, 200 °C and 300 °C in atmospheric conditions. The results show that CNT network with Pd decorated has high sensing response up to 22 % recorded at room temperature.

MATEC Web of Conferences, 2016

Asian Pacific Journal of Cancer Prevention, 2012

Measurement of quality of life among prostate cancer patients helps the health care providers to ... more Measurement of quality of life among prostate cancer patients helps the health care providers to understand the impact of the disease in the patients' own perspective. The main aim of this study is to measure the quality of life among prostate cancer patients at University Malaya Medical Center (UMMC) and Universiti Kebangsaan Malaysia Medical Centre (UKMMC) and to ascertain the association factors for physical coefficient summary (PCS) and mental coefficient summary (MCS). A hospital based, cross sectional study using the Short Form-36 (SF-36) questionnaire was conducted over a period of 6 months. A total of 193 respondents were recruited. Their total quality of life score was 70.1±14.7 and the PCS score was lower compared to MCS. The factors associated for PCS were: age, living partner, renal problem, urinary problem of intermittency, dysuria and hematuria. Factors associated for MCS were: age, living partner, renal problem, presenting prostatic specific antigen and urinary problem of intermittency and dysuria. Our prostate cancer patients had moderate quality of life in the physical health components but their mental health was less affected.