Simulation and experimental study of double-element antennas based on a three-dimensional woven structure with various curvature radii

Abstract

Three-dimensional woven fabrics have good structural embeddability, stability and integrity. In this study, three-dimensional double-element fabric antennas (3DFAs) are demonstrated by embedding the microstrip antenna structures into three-dimensional woven fabrics. In order to investigate their electromagnetic performance in practical applications, the 3DFAs are manufactured with different cylindrical radii, ranging from 45 to 75 mm. The professional antenna simulation software and experimental measurements are conducted systematically. Both results match well and support that the 3DFAs with different cylindrical curvature radii share similar rules in return losses and resonant frequencies with the planar 3DFAs. However, the gain values of the 3DFAs show different results when changing the alignment of curvature to the antenna feed direction. The gain value of the 3DFA with the curvature along the feed direction is 5 dB when the curvature radius is 75 mm, while for the 3DFA with the curvature perpendicular to the feed direction, the gain value is just 1.6 dB ( R = 75 mm), which then decreases to –2.1 dB ( R = 45 mm). Furthermore, when the curvature is along the feed direction, the 3DFAs show a better radiation pattern and directionality.