http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/59 Sun, 26 Apr 2026 00:18:40 GMT 2026-04-26T00:18:40Z http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1058 DESIGN AND OPTIMIZATION OF MICROSTRIP ARRAY ANTENNA USING BOTH-SIDED MICROWAVE INTEGRATED CIRCUIT FOR GAIN ENHANCEMENT HOSSAIN, MD. MOTAHAR In the contemporary landscape of communication systems, Microstrip Patch Antennas (MPAs) have gained immense popularity owing to their low profile, cost-effectiveness, and fabrication simplicity. In high-performance aircraft, spacecraft, satellite, and missile applications, where size, weight, cost, performance, ease of installation, and aerodynamic profile are constraints and low-profile microstrip antennas may be potent candidate. Despite their widespread use, MPAs exhibit a notable drawback in the form of low gain response. Researchers are actively engaged in overcoming this limitation, exploring diverse techniques to enhance MPA performance for specific applications. High gain antennas are particularly desirable in practical scenarios, providing extended coverage compared to their low gain counterparts. Microstrip array antennas emerge as promising candidates for achieving high gain, leveraging multiple radiating elements on a single substrate for versatile wireless applications. This thesis delves into the background and current state of the problem surrounding MPA gain limitations. Various strategies reported in the literature to address these limitations include the use of parasitic patches, thick substrates, multi-resonator techniques, conventional array techniques, large ground planes, and stacked patches. However, each technique presents its own set of drawbacks, such as increased antenna size, complexity in multilayer fabrication, and additional impedance matching circuit requirements. Notably, conventional array antennas necessitate impedance matching circuits and transmission lines for connecting array elements, leading to bulkiness and increased internal losses, thereby compromising efficiency. In response to these challenges, the thesis proposes the exploration of a novel technique both-sided MIC. Operating at microwave frequencies, this technique holds promise in mitigating the drawbacks associated with existing strategies. The thesis aims to investigate the design and optimization of a Microstrip Array Antenna utilizing both-sided MIC for gain enhancement. Through comprehensive analysis and experimentation, the goal is to establish the efficacy of this innovative approach in achieving high gain while addressing the limitations posed by traditional methods. The outcomes of this research are expected to contribute significantly to the advancement of micro strip antenna technology, opening new avenues for practical and efficient wireless communication systems. Design and Optimization of Microstrip Array Antenna using Both-Sided Microwave Integrated Circuit for Gain Enhancement Fri, 01 Mar 2024 00:00:00 GMT http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1058 2024-03-01T00:00:00Z http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1047 DESIGN AND ANALYSIS OF METAMATERIAL BASED BIOSENSOR TO DETERMINE BLOOD GLUCOSE CONCENTRATION MD. AMINUZZAMAN, MIR A biosensor utilizing metamaterials for the purpose of detecting blood glucose concentrations is designed and simulated in this study. The proposed sensor consists of a microstrip patch antenna designed on a Rogers RT5880 substrate. A circular-shaped complementary split ring resonator (CSRR) cell is integrated onto the patch of the antenna which acts as a crucial component for the glucose sensing. An investigation is conducted to determine the dimensions of the CSRR, including the number of cells, the radius of the outer and inner rings, and the location of the structure. Various shapes of CSRR, namely circular, square, and hexagonal shapes are explored in order to determine the most optimal configuration for the CSRR. The sensing zone of the sensor is determined based on the analysis of the electric field and surface current. An investigation of the characteristics of the CSRR is performed to illustrate its significance in the field of glucose detection. The sensor is analyzed in order to ascertain the concentration of glucose ranging from 50 mg/dL to 300 mg/dL in both aqueous solutions as well as a human finger model. The sensing parameter is amplitude of reflection coefficient, which exhibits variation in response to alterations in the dielectric characteristics of the sample being tested. The Debye and Cole-Cole relaxation model is employed to estimate the dielectric properties of aqueous and blood glucose solutions respectively. The glucose level is determined through the utilization of a linear regression model that describes the correlation between the magnitude of the reflection coefficient of the sensor and the concentration of glucose. The effects of varying the thickness of different finger tissues are examined. The sensor demonstrates a notable sensitivity of 1.792 dB per (mgdL-1) and is capable of determining glucose levels with a good accuracy, as validated through the application of mean absolute relative difference (MARD) and Clarke error grid analysis. The maximum 1-g specific absorption rate (SAR) of the sensor is obtained as 0.519 W/kg which ensures the RF safety of the device. This sensor exhibits enhanced performance compared to some state-of-the-art glucose sensors. Design and Analysis of Metamaterial Based Biosensor to Determine Blood Glucose Concentration Mon, 01 Jan 2024 00:00:00 GMT http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1047 2024-01-01T00:00:00Z http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1043 INFLUENCE OF HEAT TREATMENT ON ELECTRO-MECHANICAL PROPERTIES OF ALUMINUM COMPOSITES RUMI, MD JALAL UDDIN This study presents a detailed exploration of aluminum-based composites reinforced with Al2O3 and ZnO nanoparticles, employing a customized stir method, with a primary emphasis on investigating their electro-mechanical properties. Two distinct composites were developed: Al MMC-01 (97.5 wt. % Al, 2.5 wt. % Al2O3) and Al MMC-02 (95 wt. % Al, 2.5 wt. % Al2O3, 2.5 wt. % ZnO). Microstructure analysis through SEM affirmed the uniform dispersion of Al2O3 and ZnO within the metal matrix composites. The addition of 2.5% Al2O3 notably enhanced the hardness, flexural strength, and impact toughness of the Al composite compared to pure Al. However, Al MMC-02, with an additional 2.5 wt. % ZnO and 2.5 wt. % Al2O3, exhibited increased Vickers microhardness but decreased impact strength, flexural strength, flexural modulus, and electrical conductivity compared to Al MMC-01. SEM fractured surface analysis revealed the brittle nature of Al MMC-02, characterized by cleavage cracks, deep shear dimples, and crystallographic planes. Subsequent heat treatment at solution temperatures of 510°C, 530°C, and 550°C, coupled with thermal aging between 140°C and 220°C, aimed to enhance hardness and electrical conductivity. Results revealed peak increases in Vickers microhardness (25.92% for Al MMC-01, 17.6% for Al MMC-02) and electrical conductivity (9.57% for Al MMC-01, 12.12% for Al MMC-02) at a common solution temperature of 530°C compared to the as cast state. The study developed two non-linear mathematical models using a central composite design to predict heat treatment effects on Vickers microhardness (HV) and electrical conductivity (%IACS), achieving R2 values of 89.29% and 91.50%, respectively. Characterizing specific wear rates for Al MMC-01, considering parameters like applied load, sliding speed, and duration using Taguchi's Technique, identified applied load as the most impactful factor on the specific wear rate. The study developed a highly accurate regression equation to predict specific wear rates, yielding R2 and adj R2 values of 99.85% and 99.76%, respectively. Two confirmation experiments demonstrated minimal errors between experimental and predicted values (2.1% and 6.6%). INFLUENCE OF HEAT TREATMENT ON ELECTRO-MECHANICAL PROPERTIES OF ALUMINUM COMPOSITES Wed, 01 Nov 2023 00:00:00 GMT http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1043 2023-11-01T00:00:00Z http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1042 DESIGN OF A GRID CONNECTED ROOF TOP SOLAR PV SYSTEM AND ANALYSIS OF ITS EFFECT ON GRID IN CONTEXT OF BANGLADESH AL FAROOK SHIBLEE, MUHAMMAD SHAMSUL AZAM The grid-connected PV system with net energy metering is viewed as one of the best potential possibilities to improve Bangladesh's generation of renewable energy. In this study, a rooftop solar PV system for a residential building in Mirpur DOHS, Dhaka, is constructed using net metering. The findings demonstrate the extremely high energy output and yield of a rooftop PV system with net metering for residential use. The system has a low Levelized Cost of Energy (LCOE) and a positive Net Present Value (NPV), which makes it both economically and technologically appealing. It has also been investigated how much PV energy the DOHS community area could generate via net metering. In addition, a mathematical model is developed to observe the energy output variation using different tilt and azimuth combinations. Moreover, the grid stability analysis after integrating PV in the distribution feeder is also assessed for the cases like load variation, irradiance variation, three different short circuit fault condition. According to the study's findings, the rooftop PV net-metering system for residential load is practical and can be encouraged to implement as per Bangladesh's current net-metering guidelines. Design of a Grid Connected Roof Top Solar PV System and Analysis of Its Effect on Grid in Context of Bangladesh Wed, 01 Mar 2023 00:00:00 GMT http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1042 2023-03-01T00:00:00Z