Investigation on CPW koch antenna durability for microwave imaging

Abstract

In this paper, the investigation on the durability of Coplanar Waveguide (CPW) Koch antenna is presented. Increasing demands in the use of flexible antenna makes the fabric material being concerned. This antenna is made of fully fabric material. The radiating element is made of pure copper fabric and patched onto a denim jean substrate with relative permittivity, εr ≈ 2.3. The antenna is measured on the conditions of crumpled, ironed, wetted, washed, and dried for durability investigation. It produces very well performance results for all conditions except after it is washed. In washed condition, the return loss value decreases to −7.83dB. It is due to the high water content in the substrate which is influencing the originality of the substrate’s permittivity value. Thus, it leads to the decreases of antenna’s performance. However, the return loss value is still accepted for the fabric based antenna in wideband applications. Therefore, the durability of the antenna to maintain its wideband frequency characteristic in various conditions makes it has high potential to be implemented into microwave imaging application.