A Broadband UHF Tag Antenna For Near-Field and Far-Field RFID Communications

The paper deals with the design of passive broadband tag antenna for Ultra-High Frequency (UHF) band. The antenna is intended for both near and far fields Radio Frequency Identification (RFID) applications. The meander dipole tag antenna geometry modification is designed for frequency bandwidth increasing. The measured bandwidth of the proposed broadband Tag antenna is more than 140 MHz (820–960 MHz), which can cover the entire UHF RFID band. A comparison between chip impedance of datasheet and the measured chip impedance has been used in our simulations. The proposed progressive meandered antenna structure, with an overall size of 77 mm × 14 mm × 0.787 mm, produces strong and uniform magnetic field distribution in the near-field zone. The antenna impedance is matched to common UHF chips in market simply by tuning its capacitive and inductive values since a perfect matching is required in the antenna design in order to enhance the near and the far field communications. Measurements confirm that the designed antenna exhibits good performance of Tag identification for both near-field and far-field UHF RFID applications

An investigation on artificial reproduction of Mugil cephalus

Cultured nine years old breeder M. cephalus specimens were subjected to eight artificial breeding treatments from December till February 2003. In treatments 1-5, breeders received two injections of CPH and LIIRFI—A2 coupled with Domperidone or a mixture of CPH and HCG in an interval of 24 hours. Female breeders in treatments 6-8 received a gradual daily injection of 500 1U HCG per kilogram of body weight for 5 days. Male breeders in treatments 6-8 were given 5-10mg of MT-a-17 in addition to HCG and then subjected to two injections similar to that of treatments 1-5. Results showed that male breeders in stages +2 and +3 of all treatments that had received HCG produced more milt than those injected with MT-a-17, such that each male was used 2-6 times for milting purposes. Of 27 female breeders, 22 spawned 1-2.6 million eggs among which eight females' eggs were fertilized 10-95%. Hatching rate was between 0.008 to 88.9% and a maximum of 2 million larvae were produced. The best time for artificial breeding is December when mean egg width is ,600 microns. Statistical analysis of egg width, hatching rate and larvae production showed a significant difference between treatments 1-5 and 6-8 (p<0.05). This proved the supremacy of multiple injections including HCG for artificial breeding of Mugil cephalus

Digital Predistorter Design Using a Reduced Volterra Model to Linearize GaN RF Power Amplifiers

In this paper, a novel method for reducing a Simplified Volterra Series (SVS) model size is proposed for GaN RF Power Amplifier (PA) Digital Predistorter (DPD) design. Using the SVS-modified model, the number of coefficients needed for the PA behavioral modeling and predistortion can be reduced by 60 % while maintaining acceptable performances. Simulation and implementation tests are performed for a Class AB GaN PA and Doherty GaN PA using a 20-MHz Long Term Evolution-Advanced (LTE-A) signal. The Adjacent Channel Power Ratio (ACPR) attains -40 dB and -41 dB for the Doherty and Class AB GaN PAs, respectively. The implementation complexity is also studied and the obtained results prove the capability of the proposed model to linearize PA using 3% of the Slice LUTs and 87% of the DSP48E1 available in the Xilinx Zynq-7000 FPGA

Robustesse d'un contrôle vectoriel de structure minimale d'une machine asynchrone

This paper presents a robust speed control of an induction motor (1.5 kW/380 V) with a reduced computation and additionnel equipment. First a simple direct field-oriented based control law was defined. Then the robustness of the control was investigated and improved by an adaptation of the estimator to voltage harmonics and stator resistance variations, by a robust design of flux and torque controllers and by a feedforward speed control using a load torque observer. A simulation of the hardware architecture and technological characteristics of the experimental structure was developed to define an optimum configuration and to evaluate the control performance limits.Ce travail présente une nouvelle loi de commande robuste aux contraintes matérielles, pour le contrôle vectoriel d'une machine asynchrone (1,5 kW/380 V) avec un minimum de calcul et d'équipement additionnel. Nous avons défini d'abord un schéma de régulation et un estimateur des grandeurs de commande permettant d'obtenir avec un minimum de traitement numérique un contrôle direct à flux orienté. Puis, nous avons doté cette structure d'une robustesse aux contraintes matérielles par une adaptation de l'estimateur et un dimensionnement robuste de la régulation avec observation du couple de charge. Enfin, pour étudier la faisabilité du contrôle et évaluer ses performances expérimentales, nous avons effectué des simulations fines qui tiennent compte de l'architecture et des caractéristiques technologiques de la structure matérielle