Harikrishnan Ramiah, U. Eswaran and J. Kanesan
The purpose of this paper is to design and realize a high gain power amplifier (PA) with low output back-off power using the InGaP/GaAs HBT process for WCDMA applications from…
Abstract
Purpose
The purpose of this paper is to design and realize a high gain power amplifier (PA) with low output back-off power using the InGaP/GaAs HBT process for WCDMA applications from 1.85 to 1.91 GHz.
Design/methodology/approach
A three stages cascaded PA is designed which observes a high power gain. A 100 mA of quiescent current helps the PA to operate efficiently. The final stage device dimension has been selected diligently in order to deliver a high output power. The inter-stage match between the driver and main stage has been designed to provide maximum power transfer. The output matching network is constructed to deliver a high linear output power which meets the WCDMA adjacent channel leakage ratio (ACLR) requirement of −33 dBc close to the 1 dB gain compression point.
Findings
With the cascaded topology, a maximum 31.3 dB of gain is achieved at 1.9 GHz. S11 of less than −18 dB is achieved across the operating frequency band. The maximum output power is indicated to be 32.7 dBm. An ACLR of −33 dBc is achieved at maximum linear output power of 31 dBm.
Practical implications
The designed PA is an excellent candidate to be employed in the WCDMA transmitter chain without the aid of additional driver amplifier and linearization circuits.
Originality/value
In this work, a fully integrated GaAs HBT PA has been implemented which is capable to operate linearly close to its 1 dB gain compression point.
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Irfan Anjum Badruddin, Azeem Khan, Mohd Yamani Idna Idris, N. Nik-Ghaali, Salman Ahmed N.J. and Abdullah A.A.A. Al-Rashed
The purpose of this paper is to highlight the advantages of a simplified algorithm to solve the problem of heat and mass transfer in porous medium by reducing the number of…
Abstract
Purpose
The purpose of this paper is to highlight the advantages of a simplified algorithm to solve the problem of heat and mass transfer in porous medium by reducing the number of partial differential equations from four to three.
Design/methodology/approach
The approach of the present paper is to develop a simplified algorithm to reduce the number of equations involved in conjugate heat transfer in porous medium.
Findings
Developed algorithm/method has many advantages over conventional method of solution for conjugate heat transfer in porous medium.
Research limitations/implications
The current work is applicable to conjugate heat transfer problem.
Practical implications
The developed algorithm is useful in reducing the number of equations to be solved, thus reducing the computational resources required.
Originality/value
Development of simplified algorithm and comparison with conventional method.
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Premmilaah Gunasegaran, Jagadheswaran Rajendran, Selvakumar Mariappan, Yusman Mohd Yusof, Zulfiqar Ali Abdul Aziz and Narendra Kumar
The purpose of this paper is to introduce a new linearization technique known as the passive linearizer technique which does not affect the power added efficiency (PAE) while…
Abstract
Purpose
The purpose of this paper is to introduce a new linearization technique known as the passive linearizer technique which does not affect the power added efficiency (PAE) while maintaining a power gain of more than 20 dB for complementary metal oxide semiconductor (CMOS) power amplifier (PA).
Design/methodology/approach
The linearization mechanism is executed with an aid of a passive linearizer implemented at the gate of the main amplifier to minimize the effect of Cgs capacitance through the generation of opposite phase response at the main amplifier. The inductor-less output matching network presents an almost lossless output matching network which contributes to high gain, PAE and output power. The linearity performance is improved without the penalty of power consumption, power gain and stability.
Findings
With this topology, the PA delivers more than 20 dB gain for the Bluetooth Low Energy (BLE) Band from 2.4 GHz to 2.5 GHz with a supply headroom of 1.8 V. At the center frequency of 2.45 GHz, the PA exhibits a gain of 23.3 dB with corresponding peak PAE of 40.11% at a maximum output power of 14.3 dBm. At a maximum linear output power of 12.7 dBm, a PAE of 37.3% has been achieved with a peak third order intermodulation product of 28.04 dBm with a power consumption of 50.58 mW. This corresponds to ACLR of – 20 dBc, thus qualifying the PA to operate for BLE operation.
Practical implications
The proposed technique is able to boost up the efficiency and output power, as well as linearize the PA closer to 1 dB compression point. This reduces the trade-off between linear output power and PAE in CMOS PA design.
Originality/value
The proposed CMOS PA can be integrated comfortably to a BLE transmitter, allowing it to reduce the transceiver’s overall power consumption.
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The purpose of this paper is to investigate the heat transfer in an arbitrary cavity filled with porous medium. The geometry of the cavity is such that an isothermal heating…
Abstract
Purpose
The purpose of this paper is to investigate the heat transfer in an arbitrary cavity filled with porous medium. The geometry of the cavity is such that an isothermal heating source is placed centrally at the bottom of the cavity. The height and width of the heating source is varied to analyses its effect on the heat transfer characteristics. The investigation is carried out for three different cases of outer boundary conditions such as two outside vertical walls being maintained at cold temperature To, two vertical and top horizontal surface being heated to. To and the third case with top surface kept at To but other surfaces being adiabatic.
Design/methodology/approach
Finite element method is used to solve the governing equations.
Findings
It is observed that the cavity exhibits unique heat transfer behavior as compared to regular cavity. The cases of boundary conditions are found to affect the heat transfer rate in the porous cavity.
Originality/value
This is original work representing the heat transfer in irregular porous cavity with various boundary conditions. This work is neither being published nor under review in any other journal.
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Ameer Ahamad Nandalur, Sarfaraz Kamangar and Irfan Anjum Badruddin
The purpose of this study was to analyze the heat transfer in a square porous cavity that has a solid block placed at its center. The prime focus of this study is to investigate…
Abstract
Purpose
The purpose of this study was to analyze the heat transfer in a square porous cavity that has a solid block placed at its center. The prime focus of this study is to investigate the effect of size of the square solid block and other physical parameters on the heat transfer rate from the hot surface into the porous medium. The left vertical surface of cavity is maintained at a hot temperature and the right vertical surface at a cool temperature, Tc. The finite element method is used to simplify the governing equations and is solved iteratively. It is noted that the size of the solid block plays a vital role in dictating the heat transfer from the hot surface to porous medium.
Design/methodology/approach
The current work is based on finite element formulation of a square porous cavity that has a solid square block placed at its center. Governing equations were solved iteratively.
Findings
The size of the solid block has a pronounced effect on the heat transfer behavior inside the porous cavity.
Originality/value
This study highlights the heat transfer due to a conducting square solid block at mid of porous cavity.
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Hasan Celik, Moghtada Mobedi, Oronzio Manca and Unver Ozkol
The purpose of this study is to determine interfacial convective heat transfer coefficient numerically, for a porous media consisting of square blocks in inline arrangement under…
Abstract
Purpose
The purpose of this study is to determine interfacial convective heat transfer coefficient numerically, for a porous media consisting of square blocks in inline arrangement under mixed convection heat transfer.
Design/methodology/approach
The continuity, momentum and energy equations are solved in dimensionless form for a representative elementary volume of porous media, numerically. The velocity and temperature fields for different values of porosity, Ri and Re numbers are obtained. The study is performed for the range of Ri number from 0.01 to 10, Re number from 100 to 500 and porosity value from 0.51 to 0.96. Based on the obtained results, the value of the interfacial convective heat transfer coefficient is calculated by using volume average method.
Findings
It was found that at low porosities (such as 0.51), the interfacial Nusselt number does not considerably change with Ri and Re numbers. However, for porous media with high Ri number and porosity (such as 10 and 0.51, respectively), secondary flows occur in the middle of the channel between rods improving heat transfer between solid and fluid, considerably. It is shown that the available correlations of interfacial heat transfer coefficient suggested for forced convection can be used for mixed convection for the porous media with low porosity (such as 0.51) or for the flow with low Ri number (such as 0.01).
Originality/value
To the best of the authors’ knowledge, there is no study on determination of interfacial convective heat transfer coefficient for mixed convection in porous media in literature. The present study might be the first study providing an accurate idea on the range of this important parameter, which will be useful particularly for researchers who study on mixed convection heat transfer in porous media, macroscopically.
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Sock Beei Yeap, Abdul Ghani Kanesan Abdullah and Lei Mee Thien
This study aims to examine the influence of transformational leadership and mindfulness on lecturers' commitment to teaching entrepreneurship with mediating effect of readiness…
Abstract
Purpose
This study aims to examine the influence of transformational leadership and mindfulness on lecturers' commitment to teaching entrepreneurship with mediating effect of readiness for change in polytechnics.
Design/methodology/approach
The study used the cross-sectional survey method. The sample participants were 171 lecturers from polytechnics. Data were analysed by using partial least squares–structural equation modelling (PLS-SEM) approach.
Findings
Findings indicated that readiness for change mediated the relationship between transformational leadership and commitment to teaching entrepreneurship. Transformational leadership and mindfulness had no significant influence on commitment to teaching entrepreneurship. Readiness for change did not mediate the relationship between mindfulness and commitment to teaching entrepreneurship.
Practical implications
Higher education should be aware of the importance of lecturers' readiness for change. This is because readiness for change is the mediator of the relationship between transformational leadership and commitment to teaching entrepreneurship.
Originality/value
The study sheds light on the explanation of mediating effect of readiness for change to influence the relationship between transformational leadership and lecturers' commitment to teaching entrepreneurship in the Malaysian polytechnic context.
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Emotional intelligence (EI) reflects an ability to acknowledge one's own emotional state and keep one's emotions in balance while recognizing emotions in others, managing…
Abstract
Purpose
Emotional intelligence (EI) reflects an ability to acknowledge one's own emotional state and keep one's emotions in balance while recognizing emotions in others, managing interactions and relationships with them and resolving conflict. Considering that police work largely involves interactions with others, the purpose of this paper is to offer a state-of-the-art review of the research on EI in policing.
Design/methodology/approach
Using several online databases, a literature search was performed to collect all peer reviewed studies on EI in policing from around the globe. The authors review the nature of this research and its major findings. They also summarize how EI was conceptualized and measured across studies.
Findings
The authors' search generated a list of 20 studies carried out in 9 countries. Almost all used survey methods and most adopted an ability-based model of EI. The most common area of focus was on correlates of EI in police officers (N = 12), followed by descriptive studies of EI in police officers (N = 5), and finally assessments of the relevance of EI for police training (N = 3).
Originality/value
Policing research has not paid enough attention to EI. To the authors' knowledge, this is the first effort to assess the state of this literature. With law enforcement agencies looking for ways to improve citizen trust and legitimacy worldwide, the preliminary evidence suggests EI warrants considerably more empirical and practical consideration.
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Tony Halim, Kanesan Muthusamy, Sie Yong Chia and Shao Wei Lam
This paper aims to be a balance of mixed management and engineering concepts that aims to fuse classical engineering methodologies into a systems engineering framework to assess…
Abstract
Purpose
This paper aims to be a balance of mixed management and engineering concepts that aims to fuse classical engineering methodologies into a systems engineering framework to assess and compare systematically and comprehensively services rendered by engineering systems.
Design/methodology/approach
An auditing framework is developed to assess the performance of engineering services in the context of engineering services found within a facility. As a result of a system heterogeneity factor, an approach to remove this confounding issue is developed to provide a different insight into the performance of engineering services.
Findings
The output of the audit exercise serves as an input to the second methodology, direct age‐adjusted failure, which overcomes systems attributes confounding issues when comparison is made between different systems populations of the same class type. This method allows management to identify areas in which extra resources are needed to improve maintenance performance.
Practical implications
The proposed standardization technique, which can be applied to system attributes other than age, overcomes the systems heterogeneity issue between localities. This research work is positioned in the context of building engineering services, as they are the most important in terms of socio‐economical impact. A case study based on an actual facilities assessment in Singapore is used to demonstrate the usefulness of such an integrated systems approach.
Originality/value
This paper presents a qualitative‐quantitative assessment framework that consists of two major methodologies to help in identifying and prioritising engineering system services in order to allocate limited resources to the appropriate engineering service so as to improve its performance.
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Cheng_Yoke Tan, Abdul Ghani Kanesan Abdullah and Abdul Jalil Ali
The purpose of this study was to examine the effects of soft skill integration in the curriculum on quality of college life of diploma business students in Malaysian private…
Abstract
Purpose
The purpose of this study was to examine the effects of soft skill integration in the curriculum on quality of college life of diploma business students in Malaysian private higher educational institutions.
Design/methodology/approach
Descriptive quantitative survey research was used to assess the views and relationship between variables from 429 business students in Peninsular Malaysia. The adapted self-administered questionnaires were distributed through stratified random sampling method. Descriptive analysis, correlation and regression analysis were used in the findings.
Findings
The results advocated significant influence from soft skill integration on quality of college life. Soft skill integration in critical thinking and problem solving especially has significant positive influence on quality of college life in all the aspects from academic, social and also facilities.
Research limitations/implications
Generalizability of the research as it was conducted in the northern region of Peninsular Malaysia only. It was also limited by subjectivity bias of the students who responded to the questionnaire.
Practical implications
The implication of this study was that it serves as an evidence-based information of soft skill integration and effects on college quality. In this way, it provides an empirical reference to the authorities for better guidelines, evaluation, control and development in the curriculum, delivery approaches, co-curriculum, campus environment or facilities.
Social implications
Local education in particular is closely linked to the neighboring community and also dependent on the socio-economic needs of the state or region. According to Kayrooz and Parker (2010), greater engagement with local issues and higher local autonomy for spending could lead to greater effectiveness and efficiencies.
Originality/value
The study was a pioneering research in the context of Malaysian private higher education, guided by Devadason et al.’s (2010) soft skill integration study in Malaysian public higher education, plus Sirgy et al.’s (2007) study on quality of college life.