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 demandfrom consumer as well as positive progress in agriculture-related industry. Malaysia alsoproduces a lot of citrus but at the same time statistics shows that the number of citrus beingimported from other countries is also high. In order to maintain the quality of citrusproduction, a non-destructive method by using monopole antenna is used in this study. Thereflection coefficient is measured at range operating frequency of 8MHz to 5 GHz. Therelationship between dielectric constant and S11 is determined. The other variables arecompared during S11 at resonance.S11 of oranges is the highest at 2.6 GHz with a value of -42.84 dB.Keywords: citrus; monopole antenna; reflection coefficien