Compact shorted C‐shaped patch antenna for ultrahigh frequency radio frequency identification tags mounted on a metallic plate

Abstract

This paper describes an ultrahigh frequency (UHF) tag antenna mounted on a metallic plate for radio frequency identification (RFID). The impedance of the proposed antenna can be tuned using various methods. The compact patch antenna consists of a C-shaped resonator and a ground plane connected to a small shorting wall and is connected to a feeding loop in the middle of the Cshaped resonator. Etching a couple of slits close to the shorting wall and a slot in the center of the C-shaped resonator provided a flexible method for adjustment to match the conjugate impedance with the UCODE 8/8 m chip (13 − j191 Ω at 915 MHz). The optimal design with an overall size of 30 × 30 × 3 mm 3 (0.092 λ 0 × 0.092 λ 0 × 0.0092 λ 0 ) yielded a high power transmission coefficient of 91% and reading range of 6.4 m for the effective isotropic radiated power (EIRP) of 4.0 W when the tag antenna was mounted on a 220 × 220 mm 2 metal plate. The proposed antenna was designed at standard frequency bands of the Federal Communications Commission (FCC, 902-928 MHz) for North America and Taiwan. Antenna fabrication and testing were performed, which revealed that the measured data were in good agreement with the simulation results.

A Low-profile UHF RFID Tag Antenna Loaded with Rectangular Loop for Double-sided Anti-metal Applications

“…The maximum read distance of the tag antenna in this study is comparable to those in references [9] and [20], while the proposed tag antenna has a lower profile. Despite the tag antennas in references [21] and [22] exhibit higher read distances in a metallic environ- ment, the proposed tag antenna has a smaller dimension. Compared to the tag antennas in references [10] and [23], the proposed tag antenna achieves a longer read distance.…”

“…The maximum read distance of the tag antenna in this study is comparable to those in references[9] and[20], while the proposed tag antenna has a lower profile. Despite the tag antennas in references[21] and[22] exhibit higher read distances in a metallic environ-…”

Shorted Patch Antenna With Multi Slots for a UHF RFID Tag Attached to a Metallic Object

“…Because the reflection coefficient (S 11 ) and power transmission coefficient () cannot be instantly measured using the VNA, to validate the matching between the input impedance of the microchip and the proposed antenna, the following equation [37] was used for calculating the tag's characteristic performance parameters S 11 and  :…”

Frequency Switchable Global RFID Tag Antennae with Metal Compatibility for Worldwide Vehicle Transportation

“…However, it increases the complexity volume of the total antenna structure. With the help of the shorting wall, the C-shaped radiating patch is connected to the ground and mounted on the metal plate (200 × 200 mm 2 ) [14]. E-shaped radiators are connected to the ground surface with the help of inductive and capacitive stubs [15].…”