AMC-backed Twin Arrow Antenna for Wearable Electronic Travel Aid System at 24 GHz
Alicia Flórez Berdasco, María Elena de Cos Gómez, Jaime Laviada, Fernando Las-Heras
TL;DR
The paper tackles the need for compact wearable radar antennas for electronic travel aids (ETAs) that minimize body exposure while enabling imaging. It introduces an AMC-backed twin Arrow antenna designed for 24.05–24.25 GHz, integrating an Artificial Magnetic Conductor (AMC) behind the radiator to suppress backward radiation and broaden the operating bandwidth without increasing footprint. Key results show ~2 dB improvements in directivity and gain, ~15 dB enhancement in the front-to-back radiation ratio, and high radiation efficiency, with measured data closely matching simulations. Imaging demonstrations using SAR with natural body motion validate the antenna’s practicality for ETA applications, showing accurate detection and sizing of a nearby target at short range.
Abstract
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.