Design and Analysis of Microwave Sensor for Alcohol Concentration with Microstrip Band Stop Filter

This paper proposed the design and analysis of the microwave sensor (MS) in line with the microstrip band stop filter (MBSF). The research includes the measurement of alcohol concentrations ranging from 0 to 55%. The measurement was conducted using a network analyzer operating from 100 kHz to 4.5 GHz. The measurements were the insertion loss (S
21
). The obtained results indicated differences in frequency shifts. The results of the frequency values were observed to be 0, 0.06, 0.14, 0.17, 0.21, 0.23, 0.25, 0.27, and 0.31 GHz, respectively. The percentage correlation between the frequency shift in the insertion loss and frequency was evident, even after adjusting the range of the tested samples.