A. K. M. Baki

Ahsanullah University of Science and Technology

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Co-Authors

Nemai Chandra Karmakar

Monash University

Hiroshi Matsumoto

Okayama University

Kouichi Hashimoto

Hiroshima University

Tomohiko Mitani

Kyoto University

Naohide Shinohara

National Institute of Advanced Industrial Science and Technology

Shamria Sabatina Latif

University of Lethbridge

K. Hashimoto

Kyoto University

Tafsir Ahmed Khan

Ahsanullah University of Science and Technology

Shafquat Yasar Aurko

Ahsanullah University of Science and Technology

Silvia Tasnim

Ahsanullah University of Science and Technology

Cooperative Institutions

Ahsanullah University of Science and Technology

Kyoto University

Independent University

Kyoto Bunkyo University

United Nations University Institute for Sustainability and Peace

Osaka University

The University of Tokyo

Research Institute for Sustainable Humanosphere

Bangladesh University of Engineering and Technology

Kagoshima University

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Performance Comparison of RFID Tag at UHF Band and Millimeter-Wave Band

Journal of Networks (2014)

A. K. M. Baki Nemai Chandra Karmakar

The ultra high frequency (UHF) band spectrum will likely be congested in near future since the next generation wireless as well as Radio Frequency Identification (RFID) system users will witness the use of UHF band technology with increased demand of bandwidth, bit rate, frequency spectrum and power consumption. The alternate solution is the use of millimeter-wave band technology. It is possible to improve data throughput, range resolution and multi-user capability in mm-wave band RFID system. ‘Higher power reception efficiency and lower side lobe level (SLL) of radiation pattern’ is required for RFID system that will increase the tag range and transmission bit rate. At the same time lower SLL will minimize the interference level. Beam pointing error is another problem of UHF band antenna which reduces the tag range and bit rate. These problems can be minimized by using large number of antenna elements. But with UHF band signal it is practically difficult to construct large array antenna; since the array size becomes tremendously larger with the increase of antenna elements. ‘Higher power reception efficiency and lower SLL’ can practically be obtained by using non-uniform power distribution of large number of antenna elements in millimeter wave band. A new and technically better method of beam forming by implementing the concept of staircase power distribution (SPD) of antenna elements at 60 GHz has been investigated and presented in the paper. The SPD method is compared with Gaussian edge tapering method. It was found that the maximum SLL (MSLL) is the lowest in case of SPD. The beam efficiency of SPD is also equivalent to that of Gaussian edge tapering method. It is easier to fabricate a larger number of antenna elements within smaller area with SPD at 60 GHz system; since the antenna size is smaller and the number of different power distribution in SPD case is less and stepwise uniform. Uniform and less number of different power distribution of SPD also minimizes other technical errors.

Extremely high frequency

10.4304/jnw.9.12.3215-3220

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Citations (3)

Towards the Realization of an Intelligent Reflecting Surface with full 360° Phase Variation for Beam Steering Applications at C and X Bands

IEEE Access (2024)

A. K. M. Baki A. Chowdhury M. Hasan

Realization (probability)

Beam steering

Variation (astronomy)

10.1109/access.2024.3443120

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Isosceles-Trapezoidal-Distribution Edge Tapered Array Antenna with Unequal Element Spacing for Solar Power Satellite

IEICE Transactions on Communications (2008)

A. K. M. Baki Kouichi Hashimoto Naohide Shinohara Tomohiko Mitani Hiroshi Matsumoto

The Earth will require sustainable electricity sources equivalent to 3 to 5 times the commercial power presently produced by 2050. Solar Power Satellite (SPS) is one option for meeting the huge future energy demand. SPS can send enormous amounts of power to the Earth as the form of microwave (MW). A highly efficient microwave power transmission (MPT) system is needed for SPS. A critical goal of SPS is to maintain highest Beam Efficiency (BE) because the microwaves from SPS will be converted to utility power unlike the MW from communication satellites. Another critical goal of SPS is to maintain Side Lobe Levels (SLL) as small as possible to reduce interference to other communication systems. One way to decrease SLL and increase BE is the edge tapering of a phased array antenna. However, tapering the excitation requires a technically complicated system. Another way of achieving minimum SLL is with randomly spaced element position but it does not guarantee higher BE and the determination of random element position is also a difficult task. Isosceles Trapezoidal Distribution (ITD) edge tapered antenna was studied for SPS as an optimization between full edge tapering and uniform amplitude distribution. The highest Beam Collection Efficiency (BCE) and lowest SLL (except maximum SLL) are possible to achieve in ITD edge tapering and ITD edge tapered antenna is technically better. The perfor-mance of ITD is further improved from the perspective of both Maximum Side Lobe Level (MSLL) and BE by using unequal spacing of the antenna elements. A remarkable reduction in MSLL is achieved with ITD edge tapering with Unequal element spacing (ITDU). BE was also highest in ITDU. Determination of unequal element position for ITDU is very easy. ITDU is a newer concept that is experimented for the first time. The merits of ITDU over ITD and Gaussian edge tapering are discussed.

Tapering

Side lobe

Microwave transmission

10.1093/ietcom/e91-b.2.527

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Citations (29)

Calibrated_Time-Frequency_MUSIC method for direction of arrival measurement of pilot signals

A. K. M. Baki K. Hashimoto Naoki Shinohara Tomohiko Mitani Mitsuharu Matsumoto

The accuracy of the microwave (MW) power beam steering is one of the most critical goals for Solar Power Satellite (SPS). Retrodirective beam control system is the proposed method of beam steering technique for SPS. Detection of precise Direction of Arrival (DOA) of the pilot signal in SPS system is an integral part of the retro directive beam steering. High precision DOA estimation methods like MUltiple SIgnal Classification (MUSIC) and Time-Frequency_MUSIC (TF_MUSIC) based methods require calibration of antenna gain and phase errors prior to the DOA estimation. TF_MUSIC method of DOA detection can increase the effective SNR but its performance also degrades if antenna gain and phase errors exist. The performance of conventional MUSIC was tested by an experiment. Antenna gain and phase errors were calibrated by using the MUSIC method and at the same time the DOA was estimated by calibrating the gain and phase errors and the method is named as Calibrated_MUSIC (C_MUSIC). C_MUSIC performed better than MUSIC. The performance of TF_MUSIC was also tested by the same antenna calibration data and it was found that this Calibrated_TF_MUSIC (CTF_MUSIC) performed better than the MUSIC and C_MUSIC.

Direction of arrival

Multiple signal classification

SIGNAL (programming language)

10.1109/icece.2008.4769313

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Citations (1)

Grid voltage stabilization for smart grid systems

Saurav Das Farzam Aidelkhani Somir Mustak A. K. M. Baki Md. Abdur Razzak

As the power grid is improving and increasing in size day by day, new systems must be developed and designed to control and negate the newly arising problems. This paper proposes a new system to stabilize the voltage fluctuations in grid which often occur in some situations. For example, when a large number of distributed generating resources are connected to the grid and when the load fluctuates rapidly. A system has been proposed here as a solution to the problem of under voltage problems in grid. Whenever distributed generating units such as photovoltaic cells and micro turbines are connected to the grid, the grid voltage increases above the upper acceptable level. During the over voltage situations, the proposed system will be deactivated and the energy storage system will get power from the grid; as a result, the grid-voltage will decrease to an acceptable level. The paper also describes a Grid Tie Inverter (GTI) for the system. The system consists of a monitoring mechanism which continuously monitors the grid-voltage fluctuations. If the grid-voltage falls down to a certain level the control unit will send a command to boost converter unit to boost up the voltage level of the energy storage system. In order to keep the grid-voltage constant no matter how much the load fluctuates, the boosted DC power will then be fed into the grid by using the GTI. The proposed system has been demonstrated through PSIM simulation software. The electronic controlling part of the system has been designed and demonstrated through the Proteus simulation software.

10.1109/poweri.2016.8077343

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Citations (4)

On-line partial discharge measurement within the VHF range for smart energy grid monitoring

Shamria Sabatina Latif A. K. M. Baki

Insulation quality of switchyard equipment can be determined through the measurement of the strength of partial discharges (PD). PD testing gives an indication of insulation deterioration and incipient faults in a smart grid. A continuous and on air partial discharge monitoring system can be used to determine the presence of high level partial discharge. In this paper a simpler and non-intrusive on air partial discharge monitoring system is described that has been developed and tested in the laboratory. This paper also describes a novel method of developing a PD emulator sub-system with in very high frequency (VHF) range. For detecting the PD signals several considerations for detector circuits have also been discussed. Results of the experiments delineate a feasible method for real-time condition monitoring combined with a proactive, preventative maintenance strategy that can be applied to the future smart grid monitoring system.

Condition Monitoring

Line (geometry)

10.1109/sege.2016.7589546

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60 GHz array antenna with new method of beam forming

A. K. M. Baki Nemai Chandra Karmakar

The spectrum below 10 GHz frequency will likely be congested and the spreading of millimeter wave technology in different emerging wireless applications as well as associated increase in energy consumption will be witnessed in the near future. Array antenna technology with higher beam efficiency (BE) and lower side lobe level (SLL) is required in order to increase the coverage area of wireless communication, transmission bit rate and at the same time decrease the energy consumption and interference. It is possible to achieve higher BE and lower SLL of array antenna by implementing different power distributions for different array elements. A new and technically better method of beam forming by implementing the concept of Staircase Power Distribution (SPD) of antenna elements has been investigated and compared with other edge tapering methods for 60 GHz signal. It is found that the Maximum Side Lobe Level (MSLL) is the lowest in SPD among the compared methods and the BE is also equivalent to those of other edge tapering methods. Fabrication of antenna elements with SPD technology is also easier since the number of different power distribution in SPD is least and stepwise uniform. The use of antenna elements in SPD in terms of power distribution is also the best among the compared edge tapering methods.

Tapering

Side lobe

Main lobe

10.1109/iccitechn.2012.6509800

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Citations (4)

Comparison of Rank and Condition Number of an Urban Micro (UMi) Channel at 2.4 and 5.8 GHz

K. M. Peash A. K. M. Baki

The millimeter wave (mmWave) frequency band can potentially become one of the most significant contributors in meeting the demand for faster wireless communications with increased capacity. The Multiple Input Multiple Output (MIMO) technique is a promising technology for mmWave wireless communication systems. It allows for the design of communication channels that make use of spatial multiplexing. The absence of wireless communication in various applications is difficult to conceive. This paper aims to evaluate the efficacy of a massive 8×8 MIMO channel operating at 2.4 GHz. This analysis focuses on an Urban Micro (UMi) cell scenario, specifically in a non-line-of-sight (NLOS) environment. To conduct this analysis, the NYUSIM simulator is used. Furthermore, this study also includes a brief analysis of the differences in MIMO channel characteristics between carrier frequencies of 2.4 GHz and 5.8 GHz in terms of their respective condition number and rank. Various environmental parameters are considered during the simulation of MIMO systems, including foliage loss and Outdoor to Indoor (O2I) penetration loss. In order to comprehensively analyze the impacts of these factors, both co-polarized and cross-polarized scenarios are considered. The performance evaluation of MIMO channels involves analyzing various simulation results, such as the power delay profile (PDP), path loss, received power, condition number, and channel matrix rank.

Rank (graph theory)

10.1109/iccit60459.2023.10441526

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Citations (1)

A Novel and High Gain Antenna Design for Autonomous Vehicles of 6G Wireless Systems

Fahim Foysal Saheel Mahmud A. K. M. Baki

Future 6G communication systems will include full autonomous system to some applications, such as Autonomous Vehicle. Autonomous vehicle with integrated RADAR technologies will require antennas with different gains, half-power beamwidths (HPBW), and different radiation zones for different purposes such as parking assistance, lane change, emergency braking, and traffic jam assist. Millimeter-wave (mmW) frequency bands are being recommended by the Federal Communication Commission (FCC) for the vehicular RADAR system. This paper describes a novel tooth-shaped patch antenna development with better performance for autonomous vehicles. The antenna is designed at 77 GHz. The designed patch antenna exhibits lower mutual coupling effect with higher gain. Gain and current distribution of the novel tooth-shaped patch antenna was found as 9.4 dB and 1.36 *10 ⁰³ A/m. On the other hand the corresponding values in case of conventional patch were 7.2 dB and 4.99 *10 ⁰² A/m. The return loss of the tooth-shaped antenna is -37.9441 dB. The designed antenna can be used in future 6G autonomous vehicles.

Antenna gain

10.1109/gecost52368.2021.9538702

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Citations (4)

A Modified Method of Filtering for FBMC Based 5G Communications on Minimizing Doppler Shift

Adnan Mohammed Osman SM Arifur Rahman Zarin Nigar Borny A. K. M. Baki

For fifth-generation (5G) wireless technologies, one major problem is Doppler shift. In order to overcome this problem, a filter called Fractional Powered Binomial (FPBF) Windowed PHYDYAS filter is proposed in this paper for FBMC system. 5G communication and how Doppler shift worked in 5G communication have been explored in short here. For this the role of different parameters like Signal Interference Ratio (SIR), sub-carrier spacing, guard band has also been explored. The performances of this filter was compared with PHYDYAS filter through parameters like Signal to Interference Ratio (SIR), Bit Error Rate (BER), and impulse responses within the time and frequency domain. The performance of 5G communications and other parameters have been investigated through MATLAB simulations.

Raised-cosine filter

Adjacent-channel interference

10.1109/i2ct51068.2021.9417931

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Citations (5)