http://103.99.128.19:8080/xmlui/handle/123456789/29 Thesis published in Dept. of E.E.E Sat, 14 Nov 2026 12:12:36 GMT 2026-11-14T12:12:36Z http://103.99.128.19:8080/xmlui/handle/123456789/608 Circularly Polarized Microstrip Patch Array Antenna for Satellite Applications: An Approach Using Simple Feed Network Rahman, Md Mahfuzur; ID:, 19MEE003P Microstrip antennas, among various types of antennas, offer considerable ad vantages over traditional microwave antennas and are consequently utilized in numerous practical applications. Circularly polarized (CP) microstrip patch ar ray antennas offer numerous benefits, such as reduced sensitivity to polarization orientation, the capability to counteract the ionosphere’s Faraday rotation effect, enhanced resistance to interference, and improved long-distance transmission. Consequently, they play a crucial role in radar systems, satellite communica tions, GPS, and various other applications. Furthermore, a reconfigurable an tenna functions as a multifunctional apparatus, yielding a more compact and efficient design while also reducing expenses. Polarization reconfigurable anten nas can switch between various polarization modes, including LP, LHCP, and RHCP. This thesis presents the construction of a 2×2 dual-sense circularly po larized octagonal-shaped microstrip array antenna, followed by the integration of pin diodes to achieve reconfigurable circular polarization for the Ku-band fre quency suitable for satellite communication. Both antennas have a single in put feed and utilize dual-sided microwave integrated circuit (MIC) technology to enhance design flexibility and simplify the bias control circuit, resulting in a straightforward feeding circuit for the antenna. Each segment of the array is stimulated orthogonally. The switching mechanism is regulated by a single-pole double-throw (SPDT) switch composed of two PIN diodes integrated within a λ/2 delay line. The simulated outcomes indicate that the antenna may alternate between RHCP and LHCP, showcasing proficient circular polarization perfor mance. The simulated findings demonstrate excellent circular polarization (CP) performance, with a relative power level difference of 30 dB and an ARBW of 400 MHz. The array demonstrates effective impedance matching, featuring an impedance bandwidth of 1600 MHz. The gain, directivity, and efficiency find ings indicate that the antenna effectively transmits a highly focused beam in the broadside direction. A Master of Science (M.Sc) Thesis in Electrical and Electronic Engineering (EEE) Department at Chittagong University of Engineering and Technology (CUET). Mon, 28 Jul 2025 00:00:00 GMT http://103.99.128.19:8080/xmlui/handle/123456789/608 2025-07-28T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/601 Investigation of Dust-Related Energy Losses in Rooftop Solar PV Systems: A Case Study in Chittagong Town Roy, Rashmi; ID:, 21MEE016P The accumulation of dust on rooftop solar photovoltaic (PV) systems is a critical factor that reduces the overall energy output, particularly where the dust accumulation rate is higher. This thesis investigates the impact of dust accumulation on the efficiency of rooftop solar photovoltaic (PV) systems in Chittagong City in four key locations which represent different types of environmental conditions throughout the city, Likes- CUET is located in a semi-urban area, AECC is located in an industrial area, BPDB is located in a commercial area and NMI is located in an EPZ area respectively, focusing on how dust reduces solar light transmittance and, consequently, energy output and analyzes the elemental composition of the dust contributing to it. Dust samples were collected from these four locations, and analyzed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) spectroscopy, and UV transmittance tests. And also set up two 550wp solar panels on the rooftop of the CUET’s professor building block to investigate the real scenario of degradation of efficiency in a regular clean panel and unclean panel. The SEM and EDX analyses revealed significant variations in dust composition: CUET samples showed high carbon content (13.09% to 62.71%) with high light absorbing properties which originate from vehicular emissions, burning fossil fuel and industrial activities, while NMI samples had high oxygen that often bound with other elements in the form of oxides (e.g., silica as silicon dioxide, calcium oxide, iron oxide, aluminium oxide) (41.74% to 44.92%). The AECC location showed the highest silicon (commonly present as silica (SiO₂) in sand) content (up to 38%), which correlated with a notable decline in transmittance. BPDB locations also varied, with silicon, iron, and calcium being prominent in certain locations. These elements significantly affected solar transmittance, reducing the panels' energy output. The study found that dust accumulation can reduce solar light transmittance by 10% to 42%, depending on the dust composition, location and also seasonal variation — in the dry season solar transmittance is lower and in the wet season is higher. Energy output data from two 550 Wp solar PV systems at the CUET location showed the highest efficiency drop of 21.28% in April due to dust accumulation. The findings highlight the necessity for regular cleaning and maintenance of solar panels, especially in environments like Chittagong where dust accumulation is prominent. Based on the analysis, cleaning intervals and methods tailored to each location’s dust composition are recommended to optimize energy output. This research provides practical insights into improving the performance of rooftop PV systems, contributing to enhanced renewable energy efficiency in urban settings. A Master of Science (M.Sc) Thesis in Electrical and Electronic Engineering (EEE) Department at Chittagong University of Engineering and Technology (CUET). Sun, 19 Jan 2025 00:00:00 GMT http://103.99.128.19:8080/xmlui/handle/123456789/601 2025-01-19T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/586 EEG Signal Classification between Audio and Visual Stimulation and Multi-level Stress Detection Troyee, Trishita Ghosh; ID:, 21MEE005F Stress in the mind and body is a reaction to perceived difficulties or dangers. It can have significant impacts on mental and physical health, affecting cognitive abilities, emotional stability, and physical well-being. To control stress and avoid its long-term impacts, it is essential to comprehend these effects. Mental stress can be detected in many ways and Electroencephalogram (EEG) is one of them. EEG is the graphical representation of Brain's electrical activity. Regular mental stress gives rise to many mental disorders and it may cause various physiological and psychological diseases. As a result, early-stage detection of stress is very important. In this research, brain activity was recorded through EEG headset during inducing different levels of stress from audio-visual stimulus. To better evaluate visual and auditory stress, an automated system is designed to differentiate among various audio and visual evoked potentials. This may further help for designing different assistive devices for the people having visual and hearing disability. Again, many researchers worked on different level of stress detection, but four level stress detection is still unchecked. In this thesis, mental arithmetic tasks were used as both audio and visual stimuli. Here, a framework was proposed to classify different levels of stress in response to audio and visual stimuli and classification was done between these two stimuli by analyzing EEG signals. A proper pre-processing pipeline selection is essential to the effectiveness of EEG-based mental stress detection systems, as noisy EEG data are unlikely to produce improved findings. An ideal EEG pre-processing pipeline was suggested in this work and compared it to the conventional approach now in use. Using the two pre-processing pipelines, raw EEG data was pre-processed which was collected at lab environment. By extracting robust features from the denoised audio and visual data, binary and multi-level stress were classified. Four machine learning (ML) classification models were used for this purpose. On top of that, the audio and visual stimuli was classified with highest 98.37% accuracy using SVM. When the suggested pipeline for pre-processing EEG data was put into practice, a noticeable increase was found in classification accuracy over the traditional approach. With SVM, the best accuracy of 97.14%, 89.01%, 89.59% were achieved for two, three and four level stress detection using visual stimulation. By contrast, the conventional pipeline produced results of 85%, 77.67% and 66.6%. Again, for auditory stimulation, the highest accuracy of 94.51%, 87.7% and 82.63% was found for two, three and four level stress detection using SVM. On the other hand, the traditional pipeline produced results of 90%, 77.46% and 71.69% respectively. A Master of Science (M.Sc) Thesis in Electrical and Electronic Engineering (EEE) Department at Chittagong University of Engineering and Technology (CUET). Thu, 22 May 2025 00:00:00 GMT http://103.99.128.19:8080/xmlui/handle/123456789/586 2025-05-22T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/585 Techno-Economic Analysis and Design Optimization of Concentrated Solar Power Plants for Sustainable Energy Development in Bangladesh BHUIYAN, A.B.M. NOUSHAD; ID:, 21MEE025P This study assesses the feasibility of Concentrated Solar Power (CSP) in Bangladesh, evaluating four CSP technologies—Solar Tower (ST), Solar Dish (SD), Parabolic Trough Collector (PTC), and Linear Fresnel Reflector (LFR)— across the three highest Direct Normal Irradiance (DNI) regions: Cox’s Bazar, Bandarban, and Chapai Nawabganj. Key performance indicators, including capacity factor, annual energy generation, Levelized Cost of Electricity (LCOE), and Net Present Value (NPV), were analyzed. Among the technologies, PTC showed the best performance, with a 67.5% capacity factor, 889.26 GWh energy generation, and the lowest LCOE (8.98 ¢/kWh) in Chapai Nawabganj. ST had the highest energy yield (472.09 GWh) in Cox’s Bazar with a competitive LCOE (7.49 ¢/kWh). LFR demonstrated strong economic feasibility, achieving an NPV of $382.24 million and a 51.9% capacity factor. SD, while less efficient, was suitable for decentralized applications. A comparative study was conducted against existing CSP projects, including Noor II and Noor III (Morocco) and Dhursar (India), revealing that the designed plants offer higher capacity factors and lower LCOE relative to global benchmarks. The study utilized System Advisor Model (SAM) for performance optimization, considering solar field design and thermal storage integration. Key challenges include high capital costs and land constraints. Recommendations include hybrid CSP-PV systems and optimized heliostat layouts to enhance feasibility. The findings provide valuable insights for policymakers and investors, laying the groundwork for future CSP development in Bangladesh’s transition toward sustainable energy. A Master of Science (M.Sc) Thesis in Electrical and Electronic Engineering (EEE) Department at Chittagong University of Engineering and Technology (CUET). Mon, 12 May 2025 00:00:00 GMT http://103.99.128.19:8080/xmlui/handle/123456789/585 2025-05-12T00:00:00Z