| dc.description.abstract |
The rapid growth of advanced wireless communication systems has driven significant
advancements in the sensor technologies, enabling their integration into the various
aspects of daily life. Modern sensors, leveraging biomolecules, nanostructures, and
nanoelectronics, now offer capabilities such as disease detection, threat recognition,
environmental monitoring, and enhancing safety and comfort. Miniaturization of
sensors has allowed their application across diverse fields, with devices measuring
parameters like pressure, temperature, and humidity. While traditional sensor networks
rely on wired connections or battery-powered sensors, the emergence of Wireless
Sensor Networks (WSNs) offers a cost-effective, scalable solution. However, the
energy limitations of WSNs remain a challenge, which is addressed through energy
harvesting technologies that extend the sensor lifespan. Furthermore, antennas,
traditionally used for communication, have evolved to serve as sensors through
backscattering, enabling wireless data transmission without the need for batteries.
Microstrip patch antennas, with their compact, low-profile design, are increasingly
used in these systems due to their versatility and efficiency. Overall, advancements in
sensor and antenna technologies are shaping the future of wireless sensor networks,
providing eco-friendly, reliable, and affordable solutions for the large-scale data
collection, and contributing to improved environmental and human safety. These
antenna sensors may be used in agriculture to detect moisture levels, grain size and
porosity, the humidity of rice and grains, and other factors like salt and sugar detection
in water as well as the quality of water and food that aid farmers in selecting suitable
crops and offer us food quality monitoring.
This thesis presents a comprehensive study of the design, simulation, fabrication,
and application of antenna sensors in various fields, including liquid quality analysis
and agriculture. It presents novel developments in antenna sensor technology for the
quality analysis of the liquids and grains. A compact Complementary Split-Ring
Resonator (CSRR) based rectangular microstrip patch antenna sensor is designed for
detecting water quality and identifying milk adulterants such as water, caustic soda,
sodium carbonate, ammonium sulphate, and urea. Operating at 2.4 GHz with a gain of
2.5 dBi and a quality factor of 60.25, the sensor demonstrated high accuracy,
sensitivity, and reliability, making it suitable for liquid quality assessment and Wireless
Local Area Network (WLAN) applications. Additionally, microstrip and metamaterial
embedded patch sensors are developed to determine moisture content in grains,
including rice, wheat, and pulses. The metamaterial sensor, operating at 4.5 GHz,
achieved superior accuracy with Mean Relative Errors (MRE) of 1.07% for rice,
1.13% for wheat, and 1.47% for pulses, outperforming the traditional microstrip
design. Furthermore, a reconfigurable ring antenna sensor is designed to detect salt and
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sugar concentrations in water and various milk adulterants with low MRE values. The
results demonstrate the proposed sensors’ effectiveness in liquid and grain quality
analysis, offering high sensitivity, affordability, and practical applications in food
quality monitoring and wireless communication systems. The configuration and
simulation of all the proposed antenna sensors are performed using HFSS (HighFrequency Simulation Software Technology). These advancements highlight the
potential of microstrip, metamaterial, and reconfigurable antenna sensors in industrial
and consumer applications, ensuring quality control in food and beverages. |
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