AMC-backed Twin Arrow Antenna for Wearable Electronic Travel Aid System at 24 GHz

An ultra-compact wearable antenna, for electronic travel aid (ETA) applications, is presented. An AMC-backed twin arrow antenna, operative in the 24.05-24.25 GHz frequency band, has been designed for imaging systems supporting ETA. Artificial Magnetic Conductor (AMC) is combined with the antenna with the aim of reducing the backward radiation to the wearing person while improving its radiation properties and bandwidth, all this without increasing the initial area of the antenna. Prototypes of the AMC-antenna have been fabricated and measured. In order to test its performance for the application, imaging have been conducted by means of synthetic aperture radar (SAR) techniques by placing the antenna in the arm of a user to take advantage of natural body movement. Electromagnetic images have been obtained and the target has been identified, demonstrating the suitability of the AMC-antenna for the ETA system.