MHz RFID System Research Articles

Evaluation of 13.56 MHz RFID system performance considering communication distance between reader and tag

Evaluation of 13.56 MHz RFID system performance considering communication distance between reader and tag

Implementation of a RFID-based System for Library Management

Using electromagnetic coupling, an RFID tag can get power supplier by a reader and communicate with it for data exchange. Because the RFID system enables non-contact communication, various services and applications including the management of a library catalogue are possible. However, the system is affected easily by neighboring environment and the resonant frequency, thus the communication performance is degraded. In this paper, is used 13.56MHz RFID system for the management of the library. We evaluate the influence that papers or other RFID tags give to the resonant frequency of an RFID tag.

태그 수 그룹화를 통한 STAC 프로토콜의 성능 개선

In RFID system, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred as anti-collision algorithm. In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. The PS algorithm divides the tags within the identification range of reader into smaller groups by increasing the transmission power incrementally and identifies them. In this paper, we propose a STAC/PS algorithm that the PS algorithm is applied in the STAC protocol. Through simulations, it is demonstrated that the collision rate for the proposed algorithm is about 50% lower than STAC protocol. Therefore, the STAC/PS algorithm can achieve faster tag identification speed compared with STAC protocol due to the low collision rate.

디지털 데이터 슬라이서가 집적된 900 MHz 대역의 RFID 수신단

In this paper, a receiver has been developed in a CMOS technology for 900 MHz RFID communication system applications. The receiver is composed of an envelope detector, a low-pass-filter, a comparator, D flip-flops, as well as an oscillator to provide the clock for digital blocks. The receiver is designed for low power consumption, which would be suitable for passive RFID tags. In this circuit, a digital data slicer was employed instead of the conventional analog data slicer in order to reduce the power consumption. The clock frequency is 1.68 MHz and the circuit operates with a power consumption as small as . The chip size is excluding the probing pads.

응답 라운드 조기종료와 전송확률 제어를 통한 STAC 프로토콜의 성능 개선

Auto-ID 센터에서는 13.56MHz RFID 시스템에서 다중 태그를 식별하기 위한 충돌 방지 알고리즘으로 STAC 프로토콜을 제안하였다. STAC 프로토콜에서는 다음 응답 라운드의 슬롯 개수를 결정하기 위하여 태그 수 추정 기법을 적용한다. 이 경우 추정한 태그의 수에 오차가 발생하면 충돌 또는 빈 슬롯이 많이 발생할 수 있으므로 식별 성능이 저하되는 문제점이 있다. 따라서 본 논문에서는 응답 라운드 동안 빈번한 충돌 또는 빈 슬롯이 발생하면 응답 라운드를 종료하는 기법과 태그의 전송확률을 제어하는 기법을 적용한 ERPB 알고리즘을 제안하고, 이에 대한 성능을 분석한다. 시뮬레이션을 통한 성능분석의 결과, 제안한 기법은 충돌률이 STAC 프로토콜에 비하여 39% 정도 낮으므로 태그 식별 시간이 짧음을 알 수 있었다. In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. In STAC protocol, the reader uses the tag number estimation scheme to determine the number of slots for the next reply round. If errors occur in the estimated number of tags, the identification performances will be degraded due to a lot of collision or idle slots. Therefore, in this paper, we propose an ERPB algorithm that the reader cancels the reply round when it experiences a series of collision or idle slots during the current round. The transmission probability control for the tag is also applied to the proposed algorithm. Through simulations, it is demonstrated that the collision rate for the proposed scheme is about 39% lower than STAC protocol. Therefore, the proposed scheme can achieve faster tag identification time compared with STAC protocol due to the low collision rate.

Multiple Tag Identification Scheme with Early Release of Reply Round in 13.56MHz RFID System

Multiple Tag Identification Scheme with Early Release of Reply Round in 13.56MHz RFID System

Fair Identification Scheme for STAC Protocol in 13.56MHz RFID Systems

In RFID System, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred to anti-collision algorithm. In 13.56MHz RFID system, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. In STAC protocol, there is no differentiation between the collided tags and others in the identification process. Therefore, tags may never be successfully identified because its responses may always collide with others. This situation may cause the tag starvation problem. This paper proposes a fair identification scheme for STAC protocol. In the proposed scheme, if the number of collided slots is large during a query round, the reader broadcasts a CollisionRound command to begin a collision round. During the collision round, the reader identifies only tags that are experienced collision during the previous query round.

RFID 장비에 의한 인체 유도 전류의 등가 안테나 모형 연구

Recently, according to the increase of using the microwave equipments, the interests in effects on human body have been also increased. For example, there have been many researches on making the standard the specific absorbing ratio (SAR) caused by mobile phones. However, it is needed to study on the induced current on human body caused by HF(Hight Frequency) band which can deeply penetrate the human body. Especially, since the RFID systems are applied to the transportation card and the library, it is hooded to research on the effect on human body exposed to the radiated power from the RFID system. In this paper, we designed a cylindrical monopole antenna model of human body exposed to 13.56 MHz RFID system, which can model the induced current on human body. To verify the proposed equivalent antenna model, we compared the induced currents between human body and the equivalent antenna model.

Design of electrically small, folded monopole antenna using C-shaped meander for active 433.92 MHz RFID tag in metallic container application

A miniaturised RFID tag antenna for an active 433.92 MHz RFID system was designed, fabricated and measured. To attain a low profile, a folded monopole was bent and matched with a stub like an inverted-F antenna. Then the horizontal radiating segment was miniaturised with a C-shaped meander. The height of the antenna from the ground plane was 20 mm (0.029λ) and the antenna can be enclosed in a circle with a diameter of 34 mm (0.049λ). The measured −10 dB fractional bandwidth was 3.52 MHz (0.81%) and the measured gain showed a conical radiation pattern with a maximum gain of −1.33 dBd.

High speed RFID lab-scaled prototype at the frequency of 13.56 MHz

Data-intensive applications based on NFC (Near Field Communication) or applications for healthcare/e-government will need an increase of the actual defined and standardized transmission rates of 848 kbit/s. It is topic of this work to point out physical layer parameters, limitations and concepts, allowing to enhance the transmission rate of passive 13.56 MHz RFID systems. Additionally, ongoing standardization activities at ISO 14443 are pointed out, having the aim to standardize significantly enhanced datarates. Finally, an implementation of a lab-scaled prototype with a transmission rate of 6.78 Mbit/s is demonstrated and discussed.