Dr. Raimi Dewan received his Ph.D. (Electrical Engineering), Master Degree of Engineering (Electrical) and Bachelor Degree in Engineering (Electrical-Telecommunication) from Universiti Teknologi Malaysia (UTM) in 2019, 2013 and 2010 respectively. He is currently a Postdoctoral Research Fellow at the Institute of Electronics and Telecommunications of Rennes, France. He was a Senior Engineer at Keysight Technologies. He also serves as the active reviewer for various International Journals including IEEE Access, IEEE MWCL, PIER, Elsevier International Journal of Electronics and Communications, Elsevier Renewable and Sustainable Energy Reviews, WPC, IET Electronic Letter, IET MAP, International Journal of RF and Microwave Computer-Aided Engineering and IETE Journal of Research. His biography has been included in the 32nd and 33rd edition of “Who’s Who in the World” for 2015 and 2016 respectively.
Indonesian Journal of Electrical Engineering and Computer Science
A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector... more A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector is presented in this report. A microstrip patch copper was used as a switch to switch between the two modes. An FR4 substrate was used and the incidental wave angles were varied from 00 to 600. Simulations results showed that the absorber was able achieve 96% absorption at 13.05 GHz and 100% absorption at 10.00 GHz and 12.00 GHz. Furthermore, it archived over 85% absorption for the entire X-band frequency range. The AMC reflector also was able to achieve 84.97%, 82.88% and 78.69% for incident angles 00, 200 and 400 respectively. Unfortunately, the structure is polarization sensitive.
COVID-19 is a virus that spread globally, causing severe health complications and substantial eco... more COVID-19 is a virus that spread globally, causing severe health complications and substantial economic impact in various parts of the world. The COVID-19 forecast on infections is significant and crucial information that will help in executing policies and effectively reducing the daily cases. Filtering techniques are important ways to model dynamic structures because they provide good valuations over the recursive Bayesian updates. Kalman filters, one of the filtering techniques, are useful in the studying of contagious infections. Kalman filter algorithm performs an important role in the development of actual and comprehensive approaches to inhibit, learn, react, and reduce spreadable disorder outbreaks in people. The purpose of this paper is to forecast COVID-19 infections using the Kalman filter method. The Kalman filter (KF) was applied for the four most affected countries, namely the United States, India, Brazil, and Russia. Based on the results obtained, the KF method is capa...
In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wa... more In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wave (MMW) band with two configurations that exhibit different refractive indices. These two MM configurations are used to guide the antenna’s main beam in the desired direction in the 5th generation (5G) band of 28 GHz. The different refractive indices of the two MM configurations created phase change for the electromagnetic (EM) wave of the antenna, which deflected the main beam. A contiguous squares resonator (CSR) is proposed as an MM structure to operate at MMW band. The CSR is reconfigured using three switches to achieve two MM configurations with different refractive indices. The simulation results of the proposed antenna loaded by MM unit cells demonstrate that the radiation beam is deflected by angles of +30° and −27° in the E-plane, depending on the arrangement of the two MM configurations on the antenna substrate. Furthermore, these deflections are accompanied by gain enhancemen...
In this paper, an Ultra Wideband (UWB) antenna is presented. The antenna radiating patch is circu... more In this paper, an Ultra Wideband (UWB) antenna is presented. The antenna radiating patch is circular in shape with coplanar waveguide (CPW) feeding technique. The proposed chamfering to the outer edges of the ground plane successfully widens the -10 dB impedance bandwidth of the antenna to cover from 1.92 GHz up to 15.16 GHz (correspond to 155% fractional bandwidth). The antenna gain varies from 2 to 5 dB over the operating band. Parametrical studies have been conducted for four different conditions of the ground plane; without chamfering, chamfering on the inner edges, chamfering on the outer edges and both chamfering of inner and outer edges. The effects of distinguished chamfering conditions to antenna performance are analyzed. The measured and simulated results for reflection coefficients and radiation patterns (2.45 GHz, 3.5 GHz and 5.8 GHz) are presented. The corresponding realized gains are 2.14 dB, 2.85 dB and 3.4 dB respectively. The measured results satisfactorily agreed ...
Indonesian Journal of Electrical Engineering and Computer Science
<p&amp... more <p>A study on the V-shaped microstrip patch antenna for multiple-input multiple-output (MIMO) communication system based on the antenna orientation is performed. First the microstrip patch antenna operating at 2.45 GHz is calculated and simulated. Next, multiple element of antennas for MIMO system is simulated and discussed. V-shaped with 45 degree slanted inward and outward is studied. The antenna properties is analyzed and compact antenna design is determined based on the simulation results. The results shows the gap between antennas can be optimized to 1 mm while maintaining low mutual coupling. The gain of the MIMO antenna is 8.42 dBi. The simulated return losses, together with the radiation patterns, are presented and discussed.</p>
A metamaterial of electromagnetic band gap (EBG) is incorporated to an antenna for frequency reco... more A metamaterial of electromagnetic band gap (EBG) is incorporated to an antenna for frequency reconfigurability is proposed. The EBG consists of two identical unit cells that provide multiple band gaps at 1.88–1.94, 2.25–2.44, 2.67–2.94, 3.52–3.54, and 5.04–5.70 GHz with different EBG configurations. Subsequently, the antenna is incorporated with EBG. The corresponding incorporated structure successfully achieves various reconfigurable frequencies at 1.60, 1.91, 2.41, 3.26, 2.87, 5.21, and 5.54 GHz. The antenna has the potential to be implemented for Bluetooth, Wi-Fi, WiMAX, LTE, and cognitive radio applications.
International Journal of RF and Microwave Computer-Aided Engineering
Artificial Magnetic Conductor (AMC) is a type of implemented metamaterial in several antennae and... more Artificial Magnetic Conductor (AMC) is a type of implemented metamaterial in several antennae and microwave design applications. By utilizing the unique characteristics of metamaterials which do not exist naturally, the performance of various microwave devices can be enhanced. This article elaborates on the technical perspective and recent works on AMC for antenna applications. The technical perspective discusses the theoretical aspects, simulation design procedures, and the measurement setup used to characterize the AMC unit cell. Subsequently, various recent works of antenna design that involve the incorporation of AMC are discussed thoroughly. Each of the recent works is highlighted with specific performance enhancements that can be achieved with the introduction of AMC. The conventionally narrow band property of AMC, which is the bandwidth at which the radiation characteristics and directivity of the antenna can be manipulated, is discussed. The property limits the applications of AMC in wideband antenna applications. One of the techniques to improve the narrow band AMC as the ground plane is discussed in detail. The employment of AMC has solved many issues whilst overcoming the typical limitations in conventional antenna designs.
2015 IEEE Conference on Antenna Measurements & Applications (CAMA), 2015
Artificial Magnetic Conductor (AMC) is a metamaterial which is widely used nowadays in antenna de... more Artificial Magnetic Conductor (AMC) is a metamaterial which is widely used nowadays in antenna designs. AMC mimics the behavior of Perfect Magnetic Conductor (PMC) which is not available in nature. With the incorporation of AMC to antenna designs, various performance of the antenna can be improved. In this paper, AMC application in antenna design is presented for key areas of transmission enhancement between antennas, RFID detection ranges and frequency reconfigurable antenna.
A dual band Artificial Magnetic Conductor (AMC) with capacitive tuning of reflection phase at low... more A dual band Artificial Magnetic Conductor (AMC) with capacitive tuning of reflection phase at lower band frequency is proposed. The AMC operates at upper band of fixed frequency at 5.8 GHz while the lower band reconfigurable frequency is from 2.5 GHz up to 3.1 GHz. The simulated reconfigurable frequencies are 2.5, 2.62, and 3.10 GHz. The corresponding resonance structure for each band is circular patch and circular slotted ring with single capacitor per AMC unit cell. Subsequently, the AMC is incorporated with conventional UWB antenna. The effects of AMC capacitive tuning to UWB antenna performance are studied in terms of frequency reconfigurability, gain, and radiation patterns. Measurement is also carried out for the reflection coefficient and radiation patterns. Parametrical studies of the antenna such as the misalignment between the top and bottom substrate layers, air gap between the substrate layers, and capacitance tolerance of the capacitor to the reflection coefficients are also discussed.
International Journal of Electrical and Computer Engineering (IJECE), 2018
A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A ... more A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A minimal number of two EBG unit cell is deployed to realize frequency reconfigurable mechanism. By varying the state of the EBG the antenna is capable to change its dual band operation to wideband alternately. There are three cases that have been analysed, first case is the EBG incorporated antenna with ideal and second is with the active EBG. Subsequently, the third cases is the fabricated ideal EBG incorporated antenna. The dual band operation is at 1.8 GHz and 5.2 GHz while the wide band from 1.6 GHz to 2.37 GHz (770 MHz). The proposed reconfigurable antenna is suitable to be implemented for LTE (1.6 GHz), Wi-Fi (5.2 GHz), WiMAX (2.3 GHz) and cognitive radio application.
Indonesian Journal of Electrical Engineering and Computer Science
A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector... more A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector is presented in this report. A microstrip patch copper was used as a switch to switch between the two modes. An FR4 substrate was used and the incidental wave angles were varied from 00 to 600. Simulations results showed that the absorber was able achieve 96% absorption at 13.05 GHz and 100% absorption at 10.00 GHz and 12.00 GHz. Furthermore, it archived over 85% absorption for the entire X-band frequency range. The AMC reflector also was able to achieve 84.97%, 82.88% and 78.69% for incident angles 00, 200 and 400 respectively. Unfortunately, the structure is polarization sensitive.
COVID-19 is a virus that spread globally, causing severe health complications and substantial eco... more COVID-19 is a virus that spread globally, causing severe health complications and substantial economic impact in various parts of the world. The COVID-19 forecast on infections is significant and crucial information that will help in executing policies and effectively reducing the daily cases. Filtering techniques are important ways to model dynamic structures because they provide good valuations over the recursive Bayesian updates. Kalman filters, one of the filtering techniques, are useful in the studying of contagious infections. Kalman filter algorithm performs an important role in the development of actual and comprehensive approaches to inhibit, learn, react, and reduce spreadable disorder outbreaks in people. The purpose of this paper is to forecast COVID-19 infections using the Kalman filter method. The Kalman filter (KF) was applied for the four most affected countries, namely the United States, India, Brazil, and Russia. Based on the results obtained, the KF method is capa...
In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wa... more In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wave (MMW) band with two configurations that exhibit different refractive indices. These two MM configurations are used to guide the antenna’s main beam in the desired direction in the 5th generation (5G) band of 28 GHz. The different refractive indices of the two MM configurations created phase change for the electromagnetic (EM) wave of the antenna, which deflected the main beam. A contiguous squares resonator (CSR) is proposed as an MM structure to operate at MMW band. The CSR is reconfigured using three switches to achieve two MM configurations with different refractive indices. The simulation results of the proposed antenna loaded by MM unit cells demonstrate that the radiation beam is deflected by angles of +30° and −27° in the E-plane, depending on the arrangement of the two MM configurations on the antenna substrate. Furthermore, these deflections are accompanied by gain enhancemen...
In this paper, an Ultra Wideband (UWB) antenna is presented. The antenna radiating patch is circu... more In this paper, an Ultra Wideband (UWB) antenna is presented. The antenna radiating patch is circular in shape with coplanar waveguide (CPW) feeding technique. The proposed chamfering to the outer edges of the ground plane successfully widens the -10 dB impedance bandwidth of the antenna to cover from 1.92 GHz up to 15.16 GHz (correspond to 155% fractional bandwidth). The antenna gain varies from 2 to 5 dB over the operating band. Parametrical studies have been conducted for four different conditions of the ground plane; without chamfering, chamfering on the inner edges, chamfering on the outer edges and both chamfering of inner and outer edges. The effects of distinguished chamfering conditions to antenna performance are analyzed. The measured and simulated results for reflection coefficients and radiation patterns (2.45 GHz, 3.5 GHz and 5.8 GHz) are presented. The corresponding realized gains are 2.14 dB, 2.85 dB and 3.4 dB respectively. The measured results satisfactorily agreed ...
Indonesian Journal of Electrical Engineering and Computer Science
<p&amp... more <p>A study on the V-shaped microstrip patch antenna for multiple-input multiple-output (MIMO) communication system based on the antenna orientation is performed. First the microstrip patch antenna operating at 2.45 GHz is calculated and simulated. Next, multiple element of antennas for MIMO system is simulated and discussed. V-shaped with 45 degree slanted inward and outward is studied. The antenna properties is analyzed and compact antenna design is determined based on the simulation results. The results shows the gap between antennas can be optimized to 1 mm while maintaining low mutual coupling. The gain of the MIMO antenna is 8.42 dBi. The simulated return losses, together with the radiation patterns, are presented and discussed.</p>
A metamaterial of electromagnetic band gap (EBG) is incorporated to an antenna for frequency reco... more A metamaterial of electromagnetic band gap (EBG) is incorporated to an antenna for frequency reconfigurability is proposed. The EBG consists of two identical unit cells that provide multiple band gaps at 1.88–1.94, 2.25–2.44, 2.67–2.94, 3.52–3.54, and 5.04–5.70 GHz with different EBG configurations. Subsequently, the antenna is incorporated with EBG. The corresponding incorporated structure successfully achieves various reconfigurable frequencies at 1.60, 1.91, 2.41, 3.26, 2.87, 5.21, and 5.54 GHz. The antenna has the potential to be implemented for Bluetooth, Wi-Fi, WiMAX, LTE, and cognitive radio applications.
International Journal of RF and Microwave Computer-Aided Engineering
Artificial Magnetic Conductor (AMC) is a type of implemented metamaterial in several antennae and... more Artificial Magnetic Conductor (AMC) is a type of implemented metamaterial in several antennae and microwave design applications. By utilizing the unique characteristics of metamaterials which do not exist naturally, the performance of various microwave devices can be enhanced. This article elaborates on the technical perspective and recent works on AMC for antenna applications. The technical perspective discusses the theoretical aspects, simulation design procedures, and the measurement setup used to characterize the AMC unit cell. Subsequently, various recent works of antenna design that involve the incorporation of AMC are discussed thoroughly. Each of the recent works is highlighted with specific performance enhancements that can be achieved with the introduction of AMC. The conventionally narrow band property of AMC, which is the bandwidth at which the radiation characteristics and directivity of the antenna can be manipulated, is discussed. The property limits the applications of AMC in wideband antenna applications. One of the techniques to improve the narrow band AMC as the ground plane is discussed in detail. The employment of AMC has solved many issues whilst overcoming the typical limitations in conventional antenna designs.
2015 IEEE Conference on Antenna Measurements & Applications (CAMA), 2015
Artificial Magnetic Conductor (AMC) is a metamaterial which is widely used nowadays in antenna de... more Artificial Magnetic Conductor (AMC) is a metamaterial which is widely used nowadays in antenna designs. AMC mimics the behavior of Perfect Magnetic Conductor (PMC) which is not available in nature. With the incorporation of AMC to antenna designs, various performance of the antenna can be improved. In this paper, AMC application in antenna design is presented for key areas of transmission enhancement between antennas, RFID detection ranges and frequency reconfigurable antenna.
A dual band Artificial Magnetic Conductor (AMC) with capacitive tuning of reflection phase at low... more A dual band Artificial Magnetic Conductor (AMC) with capacitive tuning of reflection phase at lower band frequency is proposed. The AMC operates at upper band of fixed frequency at 5.8 GHz while the lower band reconfigurable frequency is from 2.5 GHz up to 3.1 GHz. The simulated reconfigurable frequencies are 2.5, 2.62, and 3.10 GHz. The corresponding resonance structure for each band is circular patch and circular slotted ring with single capacitor per AMC unit cell. Subsequently, the AMC is incorporated with conventional UWB antenna. The effects of AMC capacitive tuning to UWB antenna performance are studied in terms of frequency reconfigurability, gain, and radiation patterns. Measurement is also carried out for the reflection coefficient and radiation patterns. Parametrical studies of the antenna such as the misalignment between the top and bottom substrate layers, air gap between the substrate layers, and capacitance tolerance of the capacitor to the reflection coefficients are also discussed.
International Journal of Electrical and Computer Engineering (IJECE), 2018
A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A ... more A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A minimal number of two EBG unit cell is deployed to realize frequency reconfigurable mechanism. By varying the state of the EBG the antenna is capable to change its dual band operation to wideband alternately. There are three cases that have been analysed, first case is the EBG incorporated antenna with ideal and second is with the active EBG. Subsequently, the third cases is the fabricated ideal EBG incorporated antenna. The dual band operation is at 1.8 GHz and 5.2 GHz while the wide band from 1.6 GHz to 2.37 GHz (770 MHz). The proposed reconfigurable antenna is suitable to be implemented for LTE (1.6 GHz), Wi-Fi (5.2 GHz), WiMAX (2.3 GHz) and cognitive radio application.
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Papers by Raimi Dewan