Inductively Coupled Compact RFID Tag Antenna at 910 MHz With Near-Isotropic Radar Cross-Section (RCS) Patterns

Abstract

In this article, a novel wideband wavelength conversion is demonstrated using a highly nonlinear fiber consisting of a fluorinedoped fiber that has a high delta core and surrounded by a deeply depressed ring as opposed to the use of photonic crystal fibers. The wavelength conversion range is from 1460 to 1640 nm, which covers the S-, C-and L-bands of the optical network. The interacting waves consist of an arrayed waveguide grating tuned dual-wavelength fiber laser output together with a tunable laser source signal. A four-wave-mixing conversion of efficiency of À20 dB is achieved within a 70 nm tuning range within a 3.9 dB fluctuation. An optical signal to noise ratio of 30 dB is also realized within the same tuning range.

A Metallic Rfid Tag Design for Steel-Bar and Wire-Rod Management Application in the Steel Industry

“…It is well known that a small loop has a poor radiation efficiency and, hence, it is not suitable for an RFID tag with a long read-range in this design. Nevertheless it can be used as an inductively-coupled, useful feed antenna [16,17], and we use the small loop antenna for this purpose of this design. Figure 2 shows the impedance characteristics of the small loop antenna as we vary its size.…”

Improving Backscatter Radio Tag Efficiency

“…In other words, detection error is performed when the amount of noise exceeds half the distance between and . The probability of such an event can be directly computed (e.g., see Appendix A in [16]), providing an expression of the BER to the reader (18) (19) (20) where is the function [17], which decreases with increasing .…”

“…For consecutive backscattered bits from tag to reader, the average backscattered power is given (for large according to the law of large numbers) by (26) where is binomially distributed 29) where we have used (15) and the fact that , according to (27). Exploiting (29) in(25), we get (30) For example, for the 911-MHz passive tag antenna proposed in [20] and , tag efficiency variance 1 amounts to . System engineers should take into account its standard deviation and worst case analysis should be performed.…”

“…The observed ratio corresponds to gain of 7.58 dB in terms of received average carrier power per bit that could be effectively translated in an improved link budget. For example, when solution I provides a link budget that operates the reader 7 dB below its minimum received power (sensitivity) threshold, solution II can provide reception with the BER given by (20).…”

Novel CPW-fed slot antenna for UHF RFID metal tag applications

“…Generally, tag antennas using half-wavelength dipole form were studied to provide an omnidirectional coverage [2,3], but they were not suitable for practical applications due to their large sizes. Some planar antennas based on a loop-type structure to reduce tag size have been reported in [4,5]. However, these tag designs work inefficiently when placed near a metallic object.…”