Development of Microwave Reflectometer for Glucose Content Measurements

In this paper, a low-cost portable microwave reflectometer is designed and developed to measure glucose content in aqueous solution. The proposed microwave measurement system is constructed by using microwave circuit with a non-invasive open-ended coaxial probe sensor. Reflection method is used due to its simplicity and suitability of detecting the glucose concentration. The reflected microwave signal is detected by coaxial probe sensor and converted into voltage signal using power detector. Empirical models between the reflection coefficient and the glucose concentration from 10% to 60% have been developed. The reflectometer measurements are compared with Vector Network Analyser, and validated using different batch of samples. The proposed reflectometer demonstrates reasonable accuracy with an error of less than 4.5%.