Abstract A multichannel frequency-division-multiplexing (FDM) system consisting of a one-dimensio... more Abstract A multichannel frequency-division-multiplexing (FDM) system consisting of a one-dimensional photonic star waveguides (SWGs) structure is studied theoretically. This SWGs system exhibits large electromagnetic bandgaps that originate both from the periodicity of the system and the resonator’s resonant modes that create zeros of transmission. The presence of resonator defects creates two defect modes (channels of filtering) in these large gaps. Our theoretical results show that a total transmission is observed for two Eigen frequencies ( f 1 = 19.63 MHz and f 2 = 28.4 MHz) when the resonator defect length is four times the length of the undisturbed resonator. The associated quality factors reached 748 and 1132 for f 1 and f 2 respectively. A second time, another defect at the backbone level is added. The results of this research, show clearly that the backbone defect modes interact with resonators defect modes and give birth to the degeneration lifting. After this interaction, an energy transfer is obtained between the two frequencies propagating in the system. This enables us to obtain four defects modes with a very high performance when the length of backbone defect and resonator defect are suited to 2 and 1.93 m respectively.
2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016
In this paper, the Green function approach is used to study the propagation of electromagnetic wa... more In this paper, the Green function approach is used to study the propagation of electromagnetic waves through a finite photonic crystal containing two similar flat cavities. The effects of the layers thicknesses cavities and their positions on the transmission spectra are studied. The results show the occurrence of selective electromagnetic modes (one or more) in the band gaps of the periodic photonic crystal. These modes are well-defined, whose frequencies are modulated by the appropriate choice of the thicknesses and the positions of flat defects. Hence, this structure can be used in the optical telecommunications field, in the design of new filters, sensors and even for multiplexing and other engineering devices.
Journal of Electromagnetic Waves and Applications, 2020
In the framework of the Green Function approach, we determine the transmission spectrum and the b... more In the framework of the Green Function approach, we determine the transmission spectrum and the band structure of detective one-dimensional photonic star waveguides. This structure is composed of backbones’ periodicity that is characterized by negative magnetic permeability μ and positive dielectric permittivity ϵ, grafted in each site by resonators of negative permittivity and positive magnetic permeability. In the middle of the structure, we consider geometrical or/and material defect at the backbone level. The presence of such defect in this structure creates inside the photonic band gaps of the perfect structure, very narrow filtered frequencies (defect modes) with a significant quality factor Q and a very high transmission coefficient. The frequencies of the defect modes are strongly sensitive to the variation of the length and the relative permittivity of the defect. These electromagnetic characteristics of the considered structure provide good information for the design of adjustable wide gap filters.
In this paper, the authors propose a metric of radio parameters to transmit each packet on real o... more In this paper, the authors propose a metric of radio parameters to transmit each packet on real operational wireless networks with two fixed nodes exploring various narrowband channel spacing values. They study the impact of message size on the average delay in a wireless real-time application based on packet switching, thereafter, they show experimentally the existence of a relationship between modulation type, channel spacing, forwarding time and packet length. The practical results prove that forwarding time versus average message size offers a remarkable flexibility with efficiency in the transmission and gives a quick and easy idea of the possible time in the wireless bridge network performance.
2017 International Conference on Wireless Technologies, Embedded and Intelligent Systems (WITS), 2017
In this paper the importance and the impact of the optimization of the parameters which are invol... more In this paper the importance and the impact of the optimization of the parameters which are involved in the design of high index modulation filtering function are clearly demonstrated. On the basis of theoretical study and experimental measurements, we have shown that from a certain number of periods or a certain corrugation of refraction index which give a maximum gain of the filter, it is useless to overpass this optimal values. Hence, we also have shown that overpassing these optimal values does not have any effect on the gain or the mid-height bandwidth, but therefore it increases the level of losses and noise. Then, by calculating the probability of the transmission error we have proved that these distortions due to excessive values of the parameters not only degrade the performances of the propagation chain but also affect the value of the transmission covered distance.
Abstract A multichannel frequency-division-multiplexing (FDM) system consisting of a one-dimensio... more Abstract A multichannel frequency-division-multiplexing (FDM) system consisting of a one-dimensional photonic star waveguides (SWGs) structure is studied theoretically. This SWGs system exhibits large electromagnetic bandgaps that originate both from the periodicity of the system and the resonator’s resonant modes that create zeros of transmission. The presence of resonator defects creates two defect modes (channels of filtering) in these large gaps. Our theoretical results show that a total transmission is observed for two Eigen frequencies ( f 1 = 19.63 MHz and f 2 = 28.4 MHz) when the resonator defect length is four times the length of the undisturbed resonator. The associated quality factors reached 748 and 1132 for f 1 and f 2 respectively. A second time, another defect at the backbone level is added. The results of this research, show clearly that the backbone defect modes interact with resonators defect modes and give birth to the degeneration lifting. After this interaction, an energy transfer is obtained between the two frequencies propagating in the system. This enables us to obtain four defects modes with a very high performance when the length of backbone defect and resonator defect are suited to 2 and 1.93 m respectively.
2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016
In this paper, the Green function approach is used to study the propagation of electromagnetic wa... more In this paper, the Green function approach is used to study the propagation of electromagnetic waves through a finite photonic crystal containing two similar flat cavities. The effects of the layers thicknesses cavities and their positions on the transmission spectra are studied. The results show the occurrence of selective electromagnetic modes (one or more) in the band gaps of the periodic photonic crystal. These modes are well-defined, whose frequencies are modulated by the appropriate choice of the thicknesses and the positions of flat defects. Hence, this structure can be used in the optical telecommunications field, in the design of new filters, sensors and even for multiplexing and other engineering devices.
Journal of Electromagnetic Waves and Applications, 2020
In the framework of the Green Function approach, we determine the transmission spectrum and the b... more In the framework of the Green Function approach, we determine the transmission spectrum and the band structure of detective one-dimensional photonic star waveguides. This structure is composed of backbones’ periodicity that is characterized by negative magnetic permeability μ and positive dielectric permittivity ϵ, grafted in each site by resonators of negative permittivity and positive magnetic permeability. In the middle of the structure, we consider geometrical or/and material defect at the backbone level. The presence of such defect in this structure creates inside the photonic band gaps of the perfect structure, very narrow filtered frequencies (defect modes) with a significant quality factor Q and a very high transmission coefficient. The frequencies of the defect modes are strongly sensitive to the variation of the length and the relative permittivity of the defect. These electromagnetic characteristics of the considered structure provide good information for the design of adjustable wide gap filters.
In this paper, the authors propose a metric of radio parameters to transmit each packet on real o... more In this paper, the authors propose a metric of radio parameters to transmit each packet on real operational wireless networks with two fixed nodes exploring various narrowband channel spacing values. They study the impact of message size on the average delay in a wireless real-time application based on packet switching, thereafter, they show experimentally the existence of a relationship between modulation type, channel spacing, forwarding time and packet length. The practical results prove that forwarding time versus average message size offers a remarkable flexibility with efficiency in the transmission and gives a quick and easy idea of the possible time in the wireless bridge network performance.
2017 International Conference on Wireless Technologies, Embedded and Intelligent Systems (WITS), 2017
In this paper the importance and the impact of the optimization of the parameters which are invol... more In this paper the importance and the impact of the optimization of the parameters which are involved in the design of high index modulation filtering function are clearly demonstrated. On the basis of theoretical study and experimental measurements, we have shown that from a certain number of periods or a certain corrugation of refraction index which give a maximum gain of the filter, it is useless to overpass this optimal values. Hence, we also have shown that overpassing these optimal values does not have any effect on the gain or the mid-height bandwidth, but therefore it increases the level of losses and noise. Then, by calculating the probability of the transmission error we have proved that these distortions due to excessive values of the parameters not only degrade the performances of the propagation chain but also affect the value of the transmission covered distance.
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