Development of a non-destructive fruit maturity testing system utilizing radio frequency properties

Abstract

Microwaves are electromagnetic waves with wavelengths shorter than one meter and longer than one millimeter, or frequencies between 300 megahertz and 300 gigahertz. Microwave usually associated with Radio Frequency. Microwave measurements and the dielectric properties of materials are finding increasing application, as new electrotechnology is adapted for use in agriculture and food processing industries. The interest in dielectric properties of materials has historically been associated with the design of electrical equipment, where various dielectrics are used for insulating conductors and other components of electric equipment. Other than that, microwave properties have ability to determine the dielectric material when wave is directly given through that material. In the agricultural industries, determine the maturity of fruit will be taken much more time. This paper proposes microwave free-space measurement by using 2 waveguide antennas (Horn Antenna) as transmitter and receiver operating in frequency range of 2.2 – 3.3 GHz to determine the insertion loss (S21) after passing through banana which can be calculated in term of Complex Permittivity. The results from the observation show that this technique can determine fruit maturity base on the dielectric changing in the fruit sample.