Embroidered Antenna Characterization for Passive UHF RFID Tags

TL;DR

This paper presents an embroidered UHF RFID antenna integrated into clothing, demonstrating its practical functionality and comfort despite high resistive losses, suitable for smart wearable applications.

Contribution

It introduces a novel embroidered antenna design for RFID tags that maintains functionality and comfort in wearable clothing, expanding RFID integration into smart textiles.

Findings

The embroidered antenna functions effectively in RFID testing.

The embroidery pattern does not significantly affect fabric comfort.

The antenna performs well even with high resistive losses.

Abstract

For smart clothing integration with the wireless system based on radio frequency (RF) backscattering, we demonstrate an ultra-high frequency (UHF) antenna constructed from embroidered conductive threads. Sewn into a fabric backing, the T-match antenna design mimics a commercial UHF RFID tag, which was also used for comparative testing. Bonded to the fabric antenna is the integrated circuit chip dissected from another commercial RFID tag, which allows for testing the tags under normal EPC Gen 2 operating conditions. We find that, despite of the high resistive loss of the antenna and inexact impedance matching, the fabric antenna works reasonably well as a UHF antenna both in standalone RFID testing, and during variety of ways of wearing under sweaters or as wristbands. The embroidering pattern does not affect much the feel and comfort from either side of the fabrics by our sewing method.