Subminiature panel (SMA-P) coaxial sensor for the determination of moisture content of mango cv. Chok Anan

The research describes the development of a simple, cheap and efficient open-ended coaxial sensor for the determination of moisture content of Chok Anan mango during fruit ripening from week 5 to week 17. The sensor was a modification of a standard subminiature panel (SMA-P). The finite element method was used to calculate the numerical values of the reflection coefficient. The reflection coefficient of the sensor was measured using a Microwave Network Analyzer in the frequency range from 1 to 4 GHz. The actual moisture content was obtained using standard oven drying method. A calibration equation was obtained to predict moisture content from the measured reflection coefficient at 1 GHz with accuracy within 1.5%. The results indicate that the amount of m.c. in Chok Anan mango can be determined with excellent accuracy using a SMA-P coaxial sensor as an OEC sensor

Intercomparison of methods for determination of resonant frequency shift of a microstrip patch antenna loaded with Hevea rubber latex

This paper presents an intercomparison between the finite element method, method of moment, and the variational method to determine the effect of moisture content on the resonant frequency shift of a microstrip patch loaded with wet material. The samples selected for this study were Hevea rubber latex with different percentages of moisture content from 35% to 85%. The results were compared with the measurement data in the frequency range between 1 GHz and 4 GHz. It was found that the finite element method is the most accurate among all the three computational techniques with 0.1 mean error when compared to the measured resonant frequency shift. A calibration equation was obtained to predict moisture content from the measured frequency shift with an accuracy of 2%