Robust patch-antenna for wearable WLAN applications

The design of a rectangular patch antenna with a flexible polyimide substrate for rugged wearable applications is described. During normal operation, the designed antenna radiates at 2.4 GHz in the ISM band. Due to mechanical stresses, the antenna structure is subjected to twists and turns. For rugged use, a requirement is that the twist and turns should not influence the far-field radiation pattern and gain to an intolerable extent. The impact of twist and turn angles on the antenna parameters is found in this paper. The degree to which the substrate can be bent without affecting normal antenna operation is determined. A flexural endurance polymer like polyimide is found to be suitable as a substrate for wearable antennas.