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This paper proposes a reader antenna, improving the inductive coupling with a small coil whatever its position or orientation against the reader antenna. Sub-coils are inserted and the turn number is optimized in order to improve efficiency of the inductive coupling in the case of HF RFID volume detection in keeping constant the magnetic energy generated by the reader.
This paper proposes a reader antenna, improving the inductive coupling with a small coil whatever its position or orientation against the reader antenna. Sub-coils are inserted and the turn number is optimized in order to improve efficiency of the inductive coupling in the case of HF RFID volume detection in keeping constant the magnetic energy generated by the reader.
This paper concerns an application of magnetic coupling RFID technology at 13.56 MHz (HF band) for tracking devices such as instruments. The tag size is defined to be ergonomically small compared to the hand, and fixed inside a maximum surface of 1 cm2. The case of multiple detections is considered, and consequently the reader surface of control is considered wide enough to include several instruments...
This paper focuses on tracking and objects identification by means of High Frequency magnetic coupling RFID (Radio Frequency IDentification) at 13, 56 MHz. The coil of the used RFID tags corresponds to 1.9% of the reader coil surface (120×160 cm2). To increase the size ratio between the two coils, we proposed the use of multiple twisted loops antenna. The reader antenna is consequently divided into...
This paper presents some measurements and simulations results in which small helicoidally coils are designed, in the idea to provide a RF power transfer for implanted medical devices (IMDs). In such context, the coils should be very small if they are implanted within devices, or even if they are used as an alternate solution combined with UHF antennas (ex. PIFA). The influence of the body and the...
In this article, HF RFID reader antenna including small resonant coil, operating with the magnetic coupling with the reader coil, is reported. The proposed system is used to improve surface and volume of small tag detection. The performances of such system are validated by maximization of input impedance (load modulation principle) and equivalent mutual inductance between the reader dual-coils and...
Herein, a 3D 13, 56 MHz (HF) RFID reader antenna is proposed in order to optimize detection performance whatever the tag angular positioning. The design is made of a multi-loop structure, based on serial complementary antennas, as said “twisted” antennas. The RFID tag detection is optimized by two factors which rely on the modifications of the magnetic field (i) vectorial distribution and (ii) magnitude...
This paper focus on low frequency (125 kHz) RFID by magnetic coupling, more precisely using glasstag type of tags in the context of pebble detection on the beach. The challenge is to detect over a wide area very small size tags which are highly sensitive to the orientation of the magnetic field. To improve the detection ability of the reader loop antenna, the paper proposes to exploit the principle...
A design of a reader antenna is proposed to optimize HF RFID range detection in parallel and perpendicular configuration. The reader antenna has a surface of 500 cm2, the tag corresponds to 0.7% of the reader surface. For passive RFID system, if the reader antenna does not provide the threshold energy to the tag, this one will not be detected. This is the case of the misalignment systems with great...
In this work the improvement of HF RFID detection is obtained by the addition of small resonator in the reader coil. In conventional RFID system, the link between the reader and the tag coils is the mutual inductance, the added resonator is magnetically coupled with the reader coil, and then the link is expressed by the mutual impedance. Theoretical calculation of the equivalent mutual impedance of...
Ultra-wideband (UWB) wireless underground sensor networks consist of wirelessly connected underground sensor nodes that communicate through the soil. Performances of buried antennas and of the communication link depend on the soil dielectric characteristics. The effects of soil moisture and depth, in the frequency band of 3.1–10.6 GHz, on an UWB antenna return loss and bandwidth are presented. The...
This paper summarizes some tests with Low Frequency (LF, 125 kHz) RFID tags of two types: Card and Token. These tests were done in order to evaluate the feasibility of an identification/traceability of tags which size is constrained and supposed to be detected inside a delimited volume of 40×40×10 cm3. As the size of the antenna tag is supposed to be very small, we improve the detection range and...
In this paper, we present a bandpass filter designed and implemented in 65-nm CMOS. From 0.8–2.2GHz filtering requirements are very challenging. This filter is dedicated to fully digital RF Tx cellular architectures, and is available for any Tx architecture. Our filter uses highly linear CMOS active inductors that exhibit Q factors above 1000 at cellular frequencies to reduce filter insertion losses...
This paper presents the design and implementation of a bandpass filter with very low insertion losses (<0.5dB) for cellular transmitters, with 0dBm capabilities. In order to obtain a high integration of the filter with existing fully digital architectures, it has been designed in CMOS 65nm technology. This filter takes full advantage of previously developed highly linear and high Q active inductors...
This paper focuses on a differential tunable active inductor in CMOS 65nm process. This tunable differential active inductor is showing some high linearity and high quality factor (Q>;1000) taking into account a wide input power range (-40 to 0dBm). The device is designed, simulated and layouted to be used in the frame of cellular transceivers for mobile applications. The feed-forward current source...
In the context of mobile communication and connectivity system evolution, new transmitter architectures should be studied in order to design nomadic multiradio low consumption transceiver. In term of efficiency, the most important element is the amplifier. In order to obtain high efficiency performance, it is possible to use several architectures associated with switched amplifier. In this paper,...
This paper gives filtering requirements for an all-digital transmitter and identifies technical and technological challenges. Herein, we highlight trade-offs implied by such a transmitter. This work targets a flexible and low power consumption transmitter, taking into account advantages of sub-micron CMOS technologies. We focused on a multi-radio transmitter for cellular standards such as GSM, WCDMA...
This paper presents a simple methodology for the design of a highly efficient PA in the context of multiradio devices. This PA belongs to the radiofrequency reconfigurable part within a transmitter. Our goal is to improve the PA efficiency over the bandwidth. The method is based on the extraction of the transistor's non-linear output parameters and the optimisation of a given class E topology to an...
In this paper, we focus on the performances optimization of a power stages for a nomadic transmitter front-end for multi-radio applications. Performance of such a front-end are to guarantee efficiency (peak and average) whatever the modulation scheme, carrier frequency and bandwidth are. Herein, we delimited the case of study to two band of interest: LTE (2-2.2 GHz) and WiMAX (3.6-3.8 GHz), and designed...
This paper presents the analysis and simulation of a high efficiency transmitter combining a polar sigma-delta modulator and a high efficiency amplifier. This study is carried out considering high PAPR (peak to average power ratio) mobile WiMax signals. Due to its high efficiency, the class E amplifier was chosen. Performances and behavior of the designed amplifier were validated through simulations...
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