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In this paper, a switchable bandstop to allpass filter using cascaded transmission line SIW resonators is proposed. The switchable filter is performed by the switchable cascaded transmission line SIW resonators using discrete PIN diodes. Therefore, it can be used for rejecting any unwanted frequencies in the communication systems. The proposed filter design is operated in K-band and targeted for millimeter wave front end system for 5G telecommunication. Two filter designs with different orientation (design A and B) are investigated for the best performance and compact size. As a result, design B is the best by giving a maximum attenuation of 39.5 dB at 26.4 GHz with the layout size of 33×30 mm.

This study investigated the combined effects of Tualang Honey (TH) and countermovement jumping (CJ) exercise for 6 weeks on bone speed of sound (SOS), bone turnover markers, and maximum jumping height in young males. Forty participants aged between 18-24 years old were randomly assigned into four groups, i.e. control (C), supplementation of TH (H), CJ exercise (J), and combined TH supplementation, and CJ exercise (JH) groups. Participants in the J and JH groups were required to jump for 2 sessions/day, 3 alternated days/week for 6 weeks. Participants in the H and JH groups consumed 20 g/day of TH for 6 weeks. Bone SOS of the participants’ leg was measured at pre- and post-tests, and it was found that there were no significant differences in participants’ bone SOS in all groups. Blood samples were analysed for determining the concentration of serum alkaline phosphatase (ALP) and serum C-terminal telopeptide of type-1 collagen (1CTP). The JH group showed a 56.3% reduction in serum 1CTP and was significantly lower (p

Purpose: The purpose of this study is to analyse the factors that influence blockchain users to utilise blockchain in e-Logistic. Also,this study identifies the relationship between supply chain capabilities, E-traceability and E-paymentintegration with blockchain and cryptocurrency. The conceptual framework of this study developed incorporating trust as an installation for a better understanding of the use of blockchain in Malaysia logistic sector. Theory: The unified theory of acceptance and use of technology (UTAUT2) by adding trust as an independent variable. This study aims to study the relationship between the main determinants of UTAUT2 and the factorsto use of blockchain and e-logistic for enhancement oflogistics industry. The conceptual framework of this study developed to merge trust as a synthesis in UTAUT2 for a better understanding ofe-logistic. Methodology: The cross-sectional approach used in this study. Four hundred seventy-eight self-administered questionnaires distributed through simple random sampling technology aimed at blockchain users in Malaysia from 25 to 44 years. Data analysis performed using PLS. The outcome of this research shows that the relationship between e-logistic, blockchain, cryptocurrency and trust have a positive and significant relationship. Significant: This research will significantly contribute to blockchain businesses and merchants in Malaysia.Also, it provides them with useful information about the interaction between the critical determinants of the supply chain capabilities, blockchainand cryptocurrency implementation in the logistics sector in Malaysia. Originality: This is one of the most recent studies that describe the blockchain and cryptocurrency in Malaysia logistics.

Purpose: The purpose of this study is toanalyses the factors that influence blockchain & bitcoin for peer money transfer. Also, this study identifies the concept of blockchain and cryptocurrency. Furthermore, the conceptual framework of this study developed incorporating trust on software as a mediator for a better understanding of the use of blockchain in a peermoney transaction. Theory: The unified theory of acceptance and use of technology (UTAUT2) by adding trustin software as an independent variable. This research also demonstrates the relationship between the blockchain and bitcoininpeer transaction. The theoretical framework of this study developed to merge trust on software as a synthesis in UTAUT2 for a better understanding of the use of blockchain for peer transaction in Malaysia. Methodology: 142 self-administered questionnaires distributed through simple random sampling technology aimed at blockchain users in Malaysia from 20 to 30 years. Data analysis performed using PLS. This studyalso demonstrate the relationship of peer transaction and trustin software have a positive and significant relationship with using blockchain& bitcoin. Significant: This research will significantly contribute to blockchain diversityin Malaysia. It is also providing them with useful information about the interaction between the critical determinants of the trust and intention of blockchain behaviourin Malaysia. Originality: This is one of the most recent studies that describe the blockchain& bitcoin fundaments and transaction policy in Malaysia.

In this article, the ultrawideband of micro-strip patch antenna is proposed bandwidth and gain were enhanced. The techniques that using to improve the gain and bandwidth are EBG slots and superstrate. The designed structure is implemented using computer simulation technology software (CST). The achievement gain of antenna is increased by 26.4% on 10.5 GHz of frequency. While the bandwidth of the proposed antenna is increased to 161%, the range from 2.67 to 26 GHz. This range of frequency is cover UWB, GPS, 5G mobile cellular, LTE, WLAN 802.11b/g UMTS2000, WiMAX, PCS1900, TD-SCDMA and Bluetooth applications. On the other hand, the ability of the superstrate allows to smaller leverage on the cross polarization accomplishment of an antenna slots. The compares between impedance bandwidth and gain by way of like the radiation patterns are debated at competence of benefit. Finally, there are perfect harmony between simulated and fabricated results.

A rectangular microstrip patch antenna over ultra-wideband with superstrate are designed and analyzed. Four iterations A, B, C, D were designs. Iterations A and B represent the parametric study of the microstrip patch antenna. Iteration C represents Ultrawide band microstrip patch antenna with peak realized gain 4.196 dB at frequency 10.12 GHz, the gain was enhance using superstrate above the microstrip patch antenna as in iteration D, a novel enhancement happens for the whole ultra-wideband frequency band (3.1–10.6 GHz) with highest salient realised gain of 5.3 dB at frequency 10.55 GHz. The proposed antenna gain at iteration D is increased by 26.49%, which is useful for many applications such as satellite communication. Simulation and discussion results of the proposed antenna are present within this paper.

Nutraceuticals provides medical and health benefits including the prevention and treatment of a disease. Nutraceuticals are naturally derived bioactive compounds that are found in foods, dietary supplements and herbal products, and have health promoting, disease preventing and medicinal properties. Nutraceuticals are the substances which are not traditionally recognized nutrients but which have positive physiological effects on the human body. Nutraceutical has advantage over the medicine because they avoid side effects. Nutraceuticals are classifying on the basis of their natural source, chemical grouping, nutrients, herbals, dietary supplements and dietary fiber. Herbal nutraceutical is used in maintaining health and act against nutritionally induced acute and chronic diseases, thereby promoting optimal health, longevity, and quality of life. The nutraceutical revolution will lead us into a new era of medicine and health, in which the food industry will become research oriented to the pharmaceutical industry. The present review has been devoted towards understanding of the nutraceuticals from different medicinal plants based on their disease specific indications.

Over the past industrial Automation have created paradigm changes in the manufacturing industry worldwide. Besides, a similar shift in expectations and radical change in our approach to manufacturing and development could be accomplished by the blockchain integration. They are bearing in mind the 4.0 industrial revolution needed for further enhancement of the manufacturing inventory. The tools of industry 4.0 are likely to shift blockchain-based. The aim of this study is to analysis and understanding of the blockchain model and integration in inventory management. Also, this research constructs a conceptual framework for inventory management. Finally, initiative and introduce an integrated model for blockchain-based inventory management.

В роботі запропонована ультра-мініатюрна модифікована кругла друкована монопольна (MCPM) антена для надширокосмугових (UWB) застосувань. Запропонована антена складається з чотирьох круглих дисків, з'єднаних зі структурою MCPM антени, що призводить до збільшення пропускної здатності антени. Заявлена MCPM антена живиться від копланарного хвилевода (CPW) для узгодження імпедансу 50 Ом. Для моделювання конструкції використовувалася підкладка Rogers RT5880 (tanδ = 0,0004 і εr = 2,2). Запропонована MCPM антена для UWB застосувань розроблена та змодельована для частот від 3 до 11 ГГц за допомогою технології комп'ютерного моделювання (CST). MCPM антена успішно спроектована та змодельована, а її параметричне дослідження виконано комплексно, щоб підтвердити новизну конструкції. Крім того, запропонована антена демонструє стабільну діаграму випромінювання з гарним підсиленням в робочій смузі. Зазначена антена також порівнюється з відповідними літературними даними, щоб диференціювати її продуктивність. Загальний розмір завершеної MCPM антени становить 0,15λ0×0,15λ0×0,0016λ0, що відповідає найнижчій робочій частоті 3 ГГц. Допрацьована MCPM антена досягає пікового підсилення 3,2 дБ і спрямованості 3,9 дБі з високим ККД 85 % на частоті 11 ГГц. Крім того, антена пропонує достатньо широку пропускну здатність для використання в UWB додатках та радіозв'язку. In this paper, an ultra-miniaturized modified circular printed monopole (MCPM) antenna is proposed for ultra-wideband (UWB) applications. The proposed antenna consists of four circular discs connected to the structure of the MCPM antenna, which leads to enhancing the antenna impedance bandwidth. The stated MCPM antenna is fed by a coplanar waveguide (CPW) to achieve a 50 Ω impedance matching. A Rogers RT5880 substrate (tanδ = 0.0004 and εr = 2.2) is employed for design simulation. The proposed UWB MCPM antenna is designed and simulated for frequencies from 3 up to 11 GHz utilizing computer simulation technology (CST) software. The MCPM antenna is successfully designed and simulated, and its parametric study is performed in a comprehensive way to validate the design novelty. Furthermore, the proposed antenna shows a stable radiation pattern with good gain in the operating band. The stated antenna is also compared with the related literature reviews to differentiate its performance. The total dimension of the finalized antenna is 0.15λ0×0.15λ0×0.0016λ0 that corresponds to the lowest operating frequency of 3 GHz. The finalized MCPM antenna achieves peak gain of 3.2 dB and directivity of 3.9 dBi with high efficiency of 85 % at 11 GHz. Besides, the antenna offers a wide enough bandwidth to be used for UWB and radio communication applications.

Education systems in Malaysia, especially higher education institutions, are currently based on blended learning. The sudden outbreak of COVID-19 has disrupted many sectors and education is not an exception. To ensure the continuity of learning, the government has suggested for e-learning to be practiced in all institutions. The study aimed to assess the challenges and perceptions of e-learning among the tertiary level students. A study was conducted through an online survey in a private institution in Malaysia from March to April 2020. Descriptive analysis was used to assess the mean score of the challenges and perceptions. A total of 1,065 respondents participated in this study. Majority of the respondents (50.2%) had positive perceptions of e-learning as it was well supported. However, challenges on the Internet speed and quota affected the e-learning effectiveness. Thus, the strategies to improve instructional design on e-learning are necessary to develop more interactive activities and at the same time suits with low internet bandwidth.

We present a case report of a 31-year-old female with arthrogryposis multiplex congenita who suffered from restrictive lung disease and who underwent pulmonary rehabilitation successfully with a robotic device. This device falls into the category of a patient-guided suspension system. The patient was admitted to the intensive care unit after an episode of pneumonia. In the general ward, she could not be weaned off oxygen and was not able to ambulate more than 3 m with assistance. During the first session of training with the robotic device, she ambulated 162 m. After six sessions of robotic therapy, she was weaned off oxygen and could walk independently. The use of patient-guided suspension systems should be explored in pulmonary rehabilitation.

In microwave medical imaging system, a monostatic radar approach can be used together with Gaussian pulse (with an ultra-wideband (UWB) frequency). In this system, eight antennas can be used for transmitting and receiving the Gaussian pulse signal and controlled by radio frequency (RF) switches. Therefore, this paper presents the performance analysis of three different single pole double throw (SPDT) switch topologies (Design A, B and C) using discrete silicon-glass PIN diodes. Then, the best performance of SPDT switch was built up to be a single pole eight throw (SP8T) switch configuration to connect with eight antennas. As result, Design C showed the highest isolation performance compared to others. Then, based on the SP8T switch of Design C, it resulted that the insertion loss was less than −2 dB and the return loss was more than 10 dB from 1 to 15 GHz. Meanwhile, the isolation bandwidth (at the minimum isolation of −15 dB) was from 1 to 14 GHz (with 13 GHz bandwidth).

Efficient feeding geometries for rectenna design at 2.45 GHz are described. The proposed rectenna consists of two layers low cost FR-4 substrates in which circular polarisation and harmonic rejection properties are embedded. A voltage doubler rectifier with open stub matching network and the radial stub is designed at the bottom substrate to transform the ac signals to a dc voltage. A right triangular slot is designed in the ground plane to suppress second and third harmonics which improves the rectenna conversion efficiency to 75.043% at an input power of 20 dBm. The proposed rectenna design has the advantages of providing circular polarisation and harmonic rejection with a compact size and low cost which makes it a good candidate for microwave power transmission applications.

One of the most famous diseases to ever roam across the globe is cancer. There are many types of cancer but the most common sites are breast, trachea, bronchus, lung, and colon cancer. Cancer can also be found pretty much in every country on earth and our country, Malaysia is not to be missed. The number of mortality in Malaysia for cancer is one of the highest and steps can be taken to help reduce the mortality rate. CancerMAS is a web-based dashboard that visualizes cancer incidence in Malaysia using cancer data that can assist cancer researchers to conduct their studies. The dashboard displays visualizations on ten of the highest cancer sites in Malaysia for male and female along with age-groups. The dashboard also presents visualizations of all cancer sites by gender and ethnic as well as the incidence by states in Malaysia. All of the visualizations are in the form of graphs. The dashboard allows the user to zoom into the graphs and isolates elements in the graphs including hovering over the graph to reveal information.

This study proposed the use of coplanar waveguide Ultrawide-band strawberry artistic shaped printed monopole (SAPM) antenna with a single-layer frequency selective surface (FSS) as the metallic plate to improve the gain of antenna application. The intersection of six cylinders is used to structure the strawberry artistic shaped radiating element, which leads to enhancing the antenna bandwidth. The proposed FSS reflectors used a $10\times10$ array with the unit cell of 6mm $\times6$ mm in introducing a center-operating frequency. This study used the FR4 substrate with coplanar waveguide (CPW) fed to print the proposed antenna, which provided a wide impedance bandwidth of 8.85 GHz (3.05–11.9GHz) that covers the licensed Ultrawide-band. The proposed FSS transmitted a stop-band transmission coefficient, which is below −10 dB with the linear reflection phase over the bandwidth in the range from 3.05 GHz to 11.9 GHz. The UWB SAPM antenna with FSS reflector showed an improvement from 1.65 dB to 7.87 dB in the lower band and 6.3 dB to 9.68 dB in the upper band with an enhancement of 6.22 dB. The gain value is enhanced by the gaping between the antenna and FSS, which has an approximately constant gain response through the band, the gain is sustained among 7.87 dB to 9.68 dB. The total dimension of the antenna is 61mm $\times 61$ mm $\times 1.6$ mm. The proposed antenna structure provides the directional and balanced far-field pattern, which is suitable for Ultrawide-band (UWB) applications and ground-penetrating radar (GPR) applications.

Logistics function as an important role in business operation. Due to the increasing competition in this industry, organization should make sure the business logistics is efficient and effective. In achieving the increase in performance and indirectly increase the profit of an organization, logistics is an important element that need be taken into consideration seriously. This paper investigates the effect of innovative, marketing and supportive capability towards logistics performance. the study has been conducted in towards the SME organization in area of Putrajaya. 117 respondents from SME’s were collected to identify the relationship of innovative, marketing and supportive capability towards the logistics performance. Hence, factor analysis was done includes the correlation and regression analysis to examine relationship that exists. The findings identify that that innovative, marketing and supportive capability that contribute to logistics performance. Index Terms —: Innovative, Marketing, Supportive, Logistics Performance

This paper presents the designs of an antenna and rectifying circuit that operate at frequency of 2.45 GHz. The antenna is designed based on aperture coupling technique to collect high amount of RF signals. The doubler rectifying circuit with two HSMS286B fast switching diodes is designed to convert the AC signals captured by the antenna to DC voltage. The antenna and rectifier designs are simulated using 4.4 permittivity low-cost FR-4 substrate. The antenna can achieve a gain of 7.73 dB, return loss less than −30 dB and bandwidth of 216 MHz. At an input power of 20 dB, the rectifying circuit can achieve an output DC voltage of 7 V. The proposed antenna and rectifier designs have the benefits of high performance and low cost that make them applicable for microwave power transfer applications.

This paper presents an action research of designed and fabricated using well insulating materials in order to ensure the coolness inside the freezer and chiller delivery box is as good minimize temperature raised. The main purpose of this study is to develop freeze and chiller delivery box that will be able to keep fresh meat during travelling long delivery. A range of freeze and chill solutions exists for that must be kept within a specific temperature range throughout the supply-and-distribution chain. This will help to minimize the activeness of bacteria to spoil the meats, at the same time it can linger the duration for meats to spoil. All affecting parameter such as temperature inside the delivery box, heat transfer rate, and natural convection flow pattern has been studied to design and development of the delivery box. Finally, temperature distribution analysis has been conducted which showed that in operating condition inside temperature are suitable to keep the fresh meats condition.

A wideband open air gap radial line slot array (RLSA) antenna is presented for point-to-point application. This article investigates the optimum slot arrangement and the effect of slot width to the RLSA antenna. Eight models were developed and simulated with slot width taking range in values from 1 to 8 mm. Results from simulation shows optimum performance at 6-mm slot width. The 2-mm slot width gave similar performance to the 6-mm slot width in term of gain and directivity. Both antennas were fabricated and measured, from the measurement; a better return loss performance of about 28% was realized at 6-mm slot width when compared to 2-mm slot width RLSA. However, both antennas produced the same gain. A better sidelobe level of 2.9 dB was achieved with the 2-mm slot width antenna. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2974–2978, 2014

This article presents a wide band linearly polarized beam squinted radial line slot array (RLSA) antenna at 5.8-GHz band. The open ended air gap technique was used to broader the bandwidth, reduce the antenna size but maintain the high-performance characteristic. The antenna implemented radiating slot design with diameter of 200 and 1.6 mm hybrid FR4 and 8-mm open ended air gap for dielectric height. The antenna also successfully fabricated and performed a good result. The measured results show a wide 38% of bandwidth with 16 dBi gain at 5.8-GHz frequency. The beamwidth obtained below 15° for E and H plane. The research found a wide band RLSA antenna can be achieved using air gap technique and will be a potential candidate for future point to point application for fixed broadband wireless access. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:938–944, 2014

In this paper, two compact electromagnetic band gap (EBG) antennas are proposed by combining a rectangular antenna with a mushroom-like EBG structure and with a novel triple side-slotted EBG (TSSEBG). Both prototype antennas can scan the main beam in the elevation (E) (−20°

This paper presents a novel design for a triple band electromagnetic band gap (EBG) structures that provides three band gaps, with operating frequency of below 10 GHz, while the ordinary mushroom like EBG structure gives only one band gap. Complexity reduction (reduce the number of unit cells and Vias) was achieved by replacing each four cells of the Mushroom like EBG by the one of double slotted type EBG (DSTEBG) or triple side slotted EBG (TSSEBG). The Mushroom like EBG was further modified by increasing its size and inserting the slots to gain more capacitance and inductance which resulted into triple band stop.The new designs wer compared with bandwidths expressed by other EBGs and -20 dB cut-off frequencies. The size of EBG element and the gap between EBG elements, and slot width were investigated to analyse their effect on the transmission response. The structures were designed from 2.54 mm Rogers RT/Duroid 6010 substrate with relative permittivity of 10.2 and loss tangent of 0.0023. Among the investigated EBGs, the single band mushroom like EBG and the triple band of the TSSEBG demonstrated better bandwidth and lower resonance frequency performance, whereas the DSTEBG showed larger bandwidth for the first and third band. The proposed EBGs could be useful in the antenna design and other microwave circuits.

An important issue in wireless communication systems, which is related to the antenna gain degradation in case of changing the main direction of the antenna radiation pattern, this variation is not approval in many communications systems. In order to improve antenna radiation performances, Electromagnetic band gap (EBG) - antenna with radiation pattern control capability is presented. Mushroom-like EBG structure for suppressing surface waves has been combined, with the switching diode to produce the radiation pattern control with improving antenna characteristics of gain, directivity and efficiency. EBG of several cells are surrounded the patch antenna and placed symmetrically for the two opposite sides, generating different radiation patterns control ability in both the elevation (E) (-20° < φ < 20°) and azimuth (Z) planes (−18° < θ < 18°). At the ground plane of antenna the diodes have been switched ON and OFF states, the EBG sector properties in stop band (connecting vias) and pass band (disconnecting vias) are altered. Using CST Microwave Studio (CST MWS) the results show the flexibility in radiation pattern control for the Z and E planes using only four diodes. Antenna directivity of 10 dBi, gain 9.86 dB and efficiency 96.5% at the operating frequency of 6 GHz, more results for all direction has been stated in Table1. Significantly, unlike a conventional beam steering, this method does not suffering from gain degradation and the main lobe gain is approximately constant for all steerig angles.

Equipment breakdown due to unavailability of spare parts is really disastrous in plant maintenance. The failure increase the cost of repair and production downtime. Therefore, it is important to understand the maintenance and inventory function in order to ensure the plant operate accordingly. Moreover, it is necessary for the plant maintenance to balance the issue of shortage and excess of inventory in plant maintenance. In view of this situation, the spare parts become a critical matters and it is good starting point to tackle the issues from looking at the perspective of spare parts inventory risk. This paper describes the development of risk technique for plant maintenance decision making purposes using the Shortage and Excess Impact Table. It also used the Breakdown Probability Table to quantify the risk for the spare part failure.

The equipment breakdown due to unavailability of spare parts has incurred challenges for the manufacturing industry in managing the inventory. Consequently, the problem of spare parts unavailability has lead the organization towards unproductive and eventually impact the financial performance. Therefore, maintaining good system has direct connection with spare parts availability. The inventory planner always strive hard to ensure that the spare parts are always available for the maintenance used. Nevertheless, maintaining high inventories of spare parts often conflict from meeting the needs of equipment reliability for the manufacturing plant. In view of this situation, management of spare parts become critical in ensuring the equipment reliability. This paper describes an innovative risk quantification technique using Binary Decision Diagram (BDD) for the spare parts inventory control. The technique modified the BDD concept by translating the failure history into binary decision. From the binary process, the data will be converted into spare parts probability table and failure impact is analyzed. These two functions of risk, will be calculated in order gain the risk in monetary value.

Radial Line Slot Array Antenna is a slot planar antenna. The slot has been arranged in radials to create a concentration of wave into a single point. The body of this antenna normally a metal with hollow cavity and slots. However, recent development on RLSA has utilized the FR4 as a substrate material. The copper is attached to the substrate and the slot is not hollow as compare to the conventional approach. This research is studying the effect of slot with dielectric substrate to the Radial Line Slot Array Antenna (RLSA). From the measurement, it is found that the slot without dielectric provide a better return loss as compare to slot with dielectric. It is also improve the bandwidth of the RLSA. However, slot with dielectric performed better on radiation pattern characteristic.

The Radial Line Slot Array (RLSA) Antenna is very pleasing due to low profile appearance and high gain characteristic. Recent research on RLSA is to produce a light weight, durable and easy fabrication process. Thus, FR4 is an alternative substrate to replace the polypropylene. This paper presents a comparison of polypropylene and FR4 dielectric substrate for linear polarized Radial Line Slot Array (RLSA) antenna at 5.8 GHz frequency. Both antennas implemented the same radiating slot design in an antenna with diameter of 200mm. The results show an improvement of radiation pattern using FR4 dielectric substrate as compare to polypropylene dielectric base. However, the reflection coefficient for polypropylene substrate show specific resonant at 5.8GHz frequency while FR4 substrate introduce multiple resonant. This paper also suggested FR4 board can be a potential substrate and major component for RLSA antenna development in future.

Human aspects in software engineering play a key role in composing effective team members. However, to date there is no general consensus on the effective personality types and diversity based on software team roles. Thus, this paper aims to discover the effective personality types and diversity based on two software team roles – team leader and programmer by using a rule-based approach. The rule-based approach by employing the rough set technique was used to discover patterns of the data selected. In this study, four main steps were involved to discover the patterns – reduct generation rules, rules generation, rules fi ltering, and rules evaluation. The results show that the rules generated achieved acceptable prediction accuracy with more than 70 per cent accuracy. In addition, the ROC value achieved 0.65, which indicates the rule-based model is valid and useful. The results reveal that the extrovert personality type is dominant for both software team roles and a homogeneous or heterogeneous team plays an equal role to determine an effective team. This study provides useful rules for decision makers to understand and get insight into selecting effective team members that lead to producing high quality software.

Radial Line Slot Array Antenna is a slot planar antenna. The slot has been arranged radially to create a concentration of wave into a single point. A slot implemented in RLSA is a rectangular aperture type. Most of the researchers in this field used 1mm slot width with half wavelength on the slot length. From the theory, the wider slot width will allow more current flow thus enhanced the antenna performance. This research is studying the effect of slot width to the Radial Line Slot Array Antenna (RLSA). From the simulation and measurement, it is found that the slot width has improved 1dBi gain, 9dB back lobe ratio and the shape of radiation pattern shape.

A prototype of Air Gap RLSA has been designed and simulated using hybrid air gap and FR4 dielectric material. The 28% wide bandwidth has been recorded through this approach. A 12.35dBi directive gain also recorded from the simulation. The 13.3 degree beamwidth of the radiation pattern is sufficient for high directional application. Since the proposed application was for Point to Point Link, this study concluded the Air Gap RLSA is a new candidate for this application.

The performances of the triple-band meandered dipole antenna backed by two different Artificial Magnetic Conductor (AMC) structures are discussed in this paper. Two kinds of AMC structures are presented namely rectangular-patch with rectangular slot and rectangular-patch with slotted rectangular and I-shaped slot. The AMCs are designed to operate at 0.92GHz and 2.45GHz. The performances of the antenna with and without the dual-band AMC ground plane are investigated in terms of return loss, realized gain and power received. It clearly shows that the printed dipole antenna has a lower gain compared to the printed dipole antenna with high-impedance structure ground plane (GP). Furthermore, the received power of the dipole antenna backed by the 2×2 rectangular-patch with slotted rectangular and I-slot AMC receives a slightly higher power compared to the dipole antenna backed by the 2×2 rectangular-patch with rectangular slot AMC.

The Radial Line Slot Array (RLSA) Antenna is known for its good characteristics such as low profile, low cost, aesthetically pleasing, ease of installation and simple structure. RLSA antenna normally applied polypropylene as a dielectric material in the middle of the radiating plate and ground plane. This research is focusing on applying FR4 as a dielectric material. The prototype has been simulated, fabricated and measured. The measurement obtained a −15dB of return loss, 11.5dBi of directivity gain and 5% antenna bandwidth.

The purpose of this work is to determine the absorption effect by using carbon as absorbing material. It will be used in anechoic chamber in order to avoid reflections that occur on the wall of the chamber. From polystyrene, the absorbers are cut into pyramidal shaped. The pyramidal shaped is chosen because it could meet the specified industrial standards which can work well at wide range of microwave frequency. To verify the performance of the absorber, a measurement is conducted to determine the absorption rate in frequency range 1 to 10 GHz. The absorber also compared to commercial absorber. The results shows carbon is a good material to absorb the microwave energy. The absorber that has been developed is a low cost with reliable performance.

In wireless data communication, an advanced nonlinear distortion analysis is required in order to see its effect to the performance of a Radio Frequency (RF) front-end system. This technical paper therefore, reports the effect of third order intermodulation (IM3) distortion on the constellation error (a key measure of modulation quality) in RF transmitter of IEEE 802.11a wireless local area network (WLAN) system. The selected RF transmitter architecture is based on the off-the-shelf components. Advanced Design System (ADS) software has been used for RF transmitter modeling and simulation. The constellation error simulation is based on the IEEE 802.11a standard. As results, two observations have been obtained. First, it is shown that the IM3 distortion in the RF transmitter for IEEE 802.11a WLAN system must be kept in minimum level in order to get lower constellation error. Second, with the same IM3 distortion level, the constellation error is very sensitive to the IM3 distortion at higher data rate (e.g. 54 Mbps) compared to lower data rate (e.g. 6 Mbps).

A triple-band dipole antenna integrated with 0.92 GHz Artificial Magnetic Conductor (AMC) is presented. The AMC structure is called a high-impedance surface (HIS) structure and is useful as a ground plane to the dipole antenna. This structure can be used to prevent the degradation of tag and antenna performance caused by the conductive materials (metal objects) and to increase the antenna gain. This paper begins by investigating the parameters in AMC design such as a patch and gap size. The AMC is characterized by the frequency where the phase of the reflection coefficient is zero degrees and has reflected wave in-phase with the incident wave.

In this paper, a meandered triple-band printed dipole antenna is proposed for Radio Frequency Identification (RFID). This meandered tri-band printed dipole antenna is designed to operate at 0.92 GHz, 2.45 GHz and 5.8 GHz with the aid of Computer Simulation Technology (CST) software. In order to achieve triple-band operation, the proposed antenna contains two branch elements, which act as an additional resonator. The designed antenna is fabricated using Taconic RF-35 substrate with a dielectric constant ( er) of 3.5 and thickness (h) of 0.508 mm. The antenna's parameters for triple-band operation are investigated and discussed. Then, this fabricated antenna is integrated with the UHF microchip to become a passive UHF tag. This tag is tested by measuring the reading distance and it is found that the proposed tag can be used for RFID application.

This paper presents the absorber in which it is designed and shaped to absorb incident radio frequency (RF) radiation. The absorber is designed using composite material since the significance of the project is to find a potential solution to construct a low cost anechoic chamber. This model of mini anechoic chamber, which is consisting of the new designed absorber, is portable and small in size so that it is more user friendly. The performance of the designed absorber are compared to commercial absorber available. The absorber that has been developed is a low cost absorber with the absorption rate is 16.6% less compared to the commercial absorber.

Recently, wireless mesh networks as a promising newcomer in wireless access technology, has caught the attention of networking industries. These networks are envisioned to support the wired backbone with a wireless backbone for providing internet connectivity to residential areas and office. WMNs have the potential to eliminate many of disadvantages by offering low-cost, wireless broadband Internet access both for fixed and mobile users. Cross-layer design have risks due to loss of protocol layer abstraction, incompatibility with existing protocols, unforeseen impact on the future design of the network, and difficult in maintenance and management. In order to improve protocol efficiency, cross layer design becomes indispensable. This article highlights some of the past achievement and promising research avenues for an important topic in the creation of future wireless mesh networks. This article also address the issue of cross layer networking in the physical layer, network layer and transport layer.