Non-Destructive Classification of Thai Cha-Nee Durian Maturity With Near-Field Reflection Mode Measurement Using a 3.4-GHz Microwave Sensor

Abstract

This paper proposes an investigation of Thai Cha-Nee durian maturity with reflection mode measurement using a simple microwave sensor based planar structure. The microwave sensor was a "Pencil-like shaped probe", which were made of a FR4 laminate; dielectric constant (r) = 4.4, dissipation factor (tan ) = 0.018, substrate thickness (h) = 1.6 mm, and copper thickness (t) = 0.035 mm. The resonant frequency was designed at 3.4 GHz to avoid interferences from wireless communication channels. The distance between sensor and durian was recommended at less than 10 mm, due to near-field region. Referring to experimental results, durian maturity was predicted by reflection coefficient ; immature  0.53, 0.28  semimature  0.43, mature  0.19, which achieved prediction accuracy at 91.55 -99.0 %.

Microwave Non-destructive Technique using a Double-ring Resonator for Classification of Transparent Flesh and Yellow gum Mangosteens

“…This technique shows a rate of 74%. X-rays and Nuclear Magnetic Resonant (NMR) were also applied to detect rotten flesh in mangosteen and durian fruit [14], [15] [16]. The transparent fruit detection technique is also carried out using microwaves which work at a frequency of 2.45 GHz.…”