Development of Microwave Sensor Using Coupled Lines for Pickled Fish Assessment

This research explores the development and analysis of a microwave sensor using a microstrip band stop filter to assess pickled fish quality (Pla Som). The sensor is designed using coupled lines in the microstrip structure, operating at a frequency of 2.45 GHz on an FR4 substrate. Measurements were conducted using a KEYSIGHT model E5063A network analyzer across a frequency range of 0.1 GHz to 3.5 GHz. The study focuses on the frequency response of the insertion loss (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</inf>) and its relationship to the quality of the pickled fish samples. The results demonstrate a clear correlation between the sensor’s response and the quality of the fish samples, highlighting the potential of microwave sensors in food quality assessment.