การศึกษาการวัดคุณสมบัติไดอิเล็กตริกของน้ำยางที่อยู่ในภาชนะแก้วด้วยสายอากาศ 2 ความถี่ที่ 2.4 และ 5.8 กิกะเฮิร์ตซ์

Abstract

This research is a study of dielectric properties measurement of rubber latex with non-contact method. This method uses a technique to measure the reflection coefficient of the reflected wave from the rubber latex with a circular patch antenna sensor. The design of a circular patch antenna was achieved by calculating the power distribution region of the circular patch antenna in a 100 ml distilled water glass container with COMSOL multiphysics program. From the result, it was found that the circular patch antenna of radius 9 millimeters was suitable for measuring the dielectric properties of distilled water in the glass container. The 9 millimeters radius patch antenna had the power distribution region of 40 mm from the patch surface at the normalized power of -40 dB. A miniaturized circular patch antenna was constructed in a smaller size from conventional circular patch antennas to 53% and could respond at 2 frequencies of 2.45 and 5.8 GHz. The antenna was used to measure the reflection coefficient of the rubber latex with 20-60% concentration. From the results, the measured data were analyzed and explained with mathematical models. The relationship between dry rubber content percentage and reflection coefficient were evaluated by showing 1.89% error.