Moisture content effect of banana leaves to radio frequency absorbing

Abstract

The aim of this paper is to express the importance of the moisture content of banana leaves to the evaluation of radio frequency (RF) absorbing performance. Radar absorbing material (RAM) is generally used in electromagnetic compatibility chambers to minimize reflections within the chamber. These materials also reduce the radar traces of air elements by minimizing RF radiation in stealth technology. Chemical substances that are used in fabricating RAM with pyramidal shape are neither cheap nor harmless to the environment. So, vegetable wastes such as bananas, coconut, and rice are studied to use as RAM. In this study, transmission line technique has been used to measure dielectric properties of the sample (banana leaves) in 8.2-12.4 GHz. It was concluded that dried banana leaves are so sensitive to environmental moisture and the RAM produced from banana leaves gives different return loss values relative to the moisture content of the sample. The water content of the sample is reduced by 5.0% and 4.9%, respectively. In this case, there is nearly 16% and 12% reduction on relatively dielectric constant, about 54% and 33% reduction on dielectric loss, finally approximately 56% and 31% reduction on return loss.