On‐body semi‐electrically‐small tag antenna for ultra high frequency radio‐frequency identification platform‐tolerant applications

Abstract

In this study, the authors proposed the impedance-flexible on-body semi-electrically-small tag antenna for the European ultra-high frequency radio-frequency identification (UHF RFID) frequency band. The radiator is based on differentially-fed coupled shorted-patches and vertical folding techniques, using a loop excitation. The proposed excitation methods enable the input impedance to be tuned to the complex impedance of typical UHF RFID chips as well as to 50 Ω impedance. In addition, the virtual electric short applied inside the structure simplifies the topology and manufacture. The antenna dimensions are 40 × 50 × 3 mm 3 (0.12 × 0.14 × 0.01 l 0) and represent the electrical size ka = 0.58 at 866 MHz. The total efficiency measured in open space exceeds 60%. In case that the antenna is situated on a human phantom, it accounts for 50%. Accordingly, the antenna provides the read range of 5.6 m (in open space) and 5.1 m (when located on human chest).

Compact Antenna for UHF-RFID Tag Tested on the Human Body for Identification Cards

“…As part of this study, a number of studies using numerous methods and approaches have been conducted in recent years to design and develop antennas for RFID labels, and finally to simulate the impact of the body on the tag antenna, in order to enhance the performances (gain and reading range) of the RFID tag, when it is fixed to the human body. [10,[11][12][13][14][15][16][17].…”

“…The reading distance of the proposed antenna varied from 3.3 to 6 m, depending on the placement of the tag in different [14] have proposed a battery-assisted RFID tag for an application for monitoring RFID tags on the human body; however, this method is effective in increasing the reading range, but the major disadvantage is the increased cost and thickness (profile) of the tag. Svanda and Polivka [15] applied the short-circuited vertical folded coupled patch cavity technique to obtain a compact size of the tag. When the tag is attached to a human chest, it can reach a reading range of 5.1 m and 5.6 m in free space.…”

Low‐Profile Flexible UHF RFID Tag Design for Wristbands Applications

“…Due to the on-body effects, many different methods and techniques have been proposed to improve the performances (e.g., gain and reading range) of the RFID tag when it is at on-body condition [4,[6][7][8][9][10][11][12]. The easiest way to improve the reading range for on-body RFID tag monitoring application is to use an active RFID tag assisted by battery as reported in [6]; however, such method will increase the cost and thickness (profile) of the RFID tag.…”

“…Recently, the technique of applying open-slot cavity technique for achieving on-body RFID tag designs has been reported [10][11][12]. To achieve compact size of 40 mm × 50 mm × 3 mm (0.12 0 × 0.14 0 × 0.01 0 ), the work in [10] has applied the vertical folded coupled shorted patch cavity technique, in which when attached to a human chest can achieve reading range of up to 5.1 m (EIRP 4W).…”

“…To achieve compact size of 40 mm × 50 mm × 3 mm (0.12 0 × 0.14 0 × 0.01 0 ), the work in [10] has applied the vertical folded coupled shorted patch cavity technique, in which when attached to a human chest can achieve reading range of up to 5.1 m (EIRP 4W). As for the cavity-slot design in [11], the patches are etched on 0.4 mm thin FR4 substrate and loaded on a 1.4 mm thick foam substrate.…”