Measurement of brix level of Malaysian local oranges at resonance frequency

The production of citrus in worldwide has increased over the years. This is due to demand from consumer as well as positive progress in agriculture-related industry. Malaysia also produces a lot of citrus but at the same time statistics shows that the number of citrus being imported from other countries is also high. In order to maintain the quality of citrus production, a non-destructive method by using monopole antenna is used in this study. The reflection coefficient is measured at range operating frequency of 8MHz to 5 GHz. The relationship between dielectric constant and S 11 is determined. The other variables are compared during S 11 at resonance. S 11 of oranges is the highest at 2.6 GHz with a value of -42.84 dB.