Seif Naoui

Dipole antenna using novel spiral split ring resonators for UHF applications

In this paper we propose a metamaterial based antenna for UHF applications. This rectangular dipole antenna is composed of periodic and homogeneous network Spiral split ring resonators (SSRR) that exhibit a negative effective permeability. The proposed approach is intended to improve the gain and directivity of the dipole antennas while miniaturizing their sizes by the inclusion of left handed metamaterials.

Improvement RFID antenna by using nested split ring resonators

This paper focuses in the first part to demonstrate the correlation between the physical quantities of nested split ring resonators and its frequency characteristics. The investigation is conducted in a parametric study based on the simulation results and the theoretical proofs. The second part is reserved for our proposed approach to develop the method of improvement and miniaturization of RFID antennas by the inclusion of metamaterials. All simulation results were made by the CST Microwave Studio.

RFID antenna by using metamaterials with negative effective permeability

In this article, we propose a new approach to study a suitable structure of metamaterial antennas for RFID technology that operates in the UHF band. This antenna is constituted by a dipole associated to a network specific and homogeneous structure composite of circular split ring resonators that can produce a negative permeability. Thanks to the effect of effective negative permeability, we can improve the performance and reduce the size of the studied antenna, which is very important for the RFID applications. The parameters considered in this paper are the resonant frequency, return loss, frequency band, radiation pattern, gain and directivity of antenna. All results of the simulations were done by CST Microwave Studio simulation software.

Improvement of the Frequency Characteristics for RFID Patch Antenna based on C-Shaped Split Ring Resonator

In this paper, we present a new technique for improving frequency characteristics and miniaturizing the geometric dimension of the RFID patch antenna that operates in the SHF band. This technique consists in implementing a periodic network based on a new model of a split C-ring resonator on the square slots of radiating rectangular patch antenna. The results of the simulation have proved that the proposed technique has an excellent radiation efficiency and size reduction compared to the reference patch antenna.

Radiation efficiency improvement of RFID patch antenna using metamaterials

A new design of a periodic Metamaterials on the radiating patch antenna is presented in this paper. This method is used to improve the total radiation efficiency and optimize return loss S11 at resonance frequency of RFID rectangular patch antenna. Based on the simulation results, we found that the proposed metamaterials antenna has a maximum radiation efficiency of 95%, higher gain of 7dB, very narrow bandwidth of 40 MHZ and a better adaptation of −28dB in the operating frequency.

Design of a chipless RFID TAG based on the frequency shift technique for K band

A novel low-cost chipless radio frequency identification (RFID) tag is presented. The tag is a patch loaded with two slots for data encoding where a single resonator encodes two bits instead of a single bit. We present a design of a 4-bit tag using frequency shift technique within the frequency band between 17.0 and 27.0 GHz. The proposed method is based on the absence or presence of resonances, as well as the resonant frequency shifts to encode data bits.

Performance Improvement of RFID Reader Antenna Using Spiral Split Ring Resonators

In this paper, a dipole antenna with Spiral Split Ring Resonators (SSRR) for RFID reader is proposed, this novel miniaturized metamaterials is characterized by a very small size compared to the classical resonator introduced by J. Pendry, then by the constituting of a negative permeability (µeff) around the resonance frequency. The dipole antenna based on metamaterials is proposed to increase the performance (Directivity, Gain and bandwidth) and reducing the dimensions of RFID reader antennas that operate in the SHF band (2.4-2.485GHz).

RFID patch antenna by using complementary split ring resonator oriented at 45 degrees

This paper is specialized to highlight the method of miniaturization and improvement the patch antenna by using the complementary metamaterial. This method is shown by two structures composed of a patch antenna integrated on its upper surface a cell of a complementary split ring resonator for the first technique. In the second structure, we replace the unit cell with a homogeneous and periodic array contain the elements of complementary split ring resonators. The magnetic resonator is placed at the middle of the radiating patch in parallel with the transmission line and with an orientation angle is fixed to 45 degrees. These two techniques widespread at the traceability applications by wireless communication for RFID technology at the operation frequency 2.45GHz. The objective is to first verify the effect of inclusion the complementary metamaterials with a patch antenna and then show the efficiency and advantage to orient the complementary split ring resonator at an angle 45 degrees. Finally, a comparison made on the two structures in order to propose the perfect technique. All simulation results were made by the CST Microwave Studio.

Electrical modeling of split ring resonators operating in the UHF band

The article in hand deals present a new approach focuses on the electric modelling of split ring resonators based on an equivalent circuit. The elements of circuit are determined from geometric parameters forming the three dimensional model of this type of resonators. Firstly an analytic study is proposed about the determination of the components of the circuit in function the physical parameters with a review about comparison between obtained results when the simulation of two different models is presented. Secondly, a demonstrative study on the effect of varying the value of the relative permittivity and determination the error rate at level the resonant frequency in the two models. The objective is to put the conditions and constraints necessary to make our equivalent circuit most responded and most efficient with zero error. The results of simulations are confirmed with using the two commercials software HFSS and ADS.