Liquid Permittivity Sensing Using Teeth Gear-Circular Substrate Integrated Waveguide

A new design of teeth gear-circular substrate integrated waveguide (TG-CSIW) sensor to extract complex permittivity of liquids is suggested in this study. The proposed sensor size is decreased up to 20% after the Angle Between Input and Output Ports (ABIOP) was introduced. As the outcome, there was a very excellent quality factor of 700 unloaded. The sensor operated at 2.45GHz resonant frequency, and it is progressively designed by the ANSYS program HFSS. The sensor's simulated response was evaluated by different permittivity of liquid under test (LUT) with an amount of 0.11mL aqueous. A strong correlation is obtained between the simulated and experimental findings of complex permittivity of LUTs with a minimal error of less than 0.4%. In addition, the modelled sensor was employed to estimate the complex permittivity of unknown specimens. It has contributed to a miniaturized, low-cost, secure, non-contact, fast-detection system utilizing limited liquid volumes filled into Polypropylene tubes. The proposed sensor is practically useful for food or beverage products, fluids/tissues of organic and natural herbs industry applications.