Hassan Haddad | INSA Rennes (original) (raw)
Papers by Hassan Haddad
Journal of Communications Technology and Electronics, 2015
Antennas are becoming crucial in an increasingly growing number of vital applications, particu la... more Antennas are becoming crucial in an increasingly growing number of vital applications, particu larly with the emergence of the 3G and 4G generations of communications. Point to multipoint configura tion is a major interest nowadays; therefore antennas are designed for this purpose where efficiency, size, and cost play a decisive role.The common practice is to refer to the already existing antennas in the market for this sole purpose. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are extremely hard to simultaneously optimize. The purpose of this project is to present a new configuration rely ing on the use of Slotted Circular Waveguide Antennas, which are initially used in Radar applications, as an ultimate alternative that allows drastically enhancing the ratio of performance versus cost. Moreover, the antenna will be remodeled and designed to function as an enhanced Circular Slotted Waveguide Antenna with optimized directional characteristics with gain above 10 dBi (to be considered as high gain). Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. A prototype was fabricated to measure its parameters and compare them with simulation results. It is still noteworthy to mention that these results matched with an elevated accuracy since the pattern simulated is meshed and modeled to a far extent taking into account all non ideal characteristics.
INSA de Rennes ; Université Libanaise - Liban, Nov 27, 2018
Antennas are becoming crucial in an increasingly growing number of applications namely with the e... more Antennas are becoming crucial in an increasingly growing number of applications namely with the emerging of the wireless internet communications, military systems like aircrafts, missiles and submarines or even oil drilling systems where efficiency, compactness and cost play a decisive role. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are hard to simultaneously optimize. In this project, an innovative approach relying on using Ring-Shaped Slotted Waveguide Antenna (RSSWA) as a good alternative is presented, that allows enhancing drastically the ratio of performance versus cost and size. Simulation results along with Experimental validations will be carried out at 2.4 GHz frequency and indubitably demonstrating high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. . Index Terms – Slot, waveguide, omnidirectional, radiation efficiency, compactness, pattern, directivity, high gain, RSSWA.
Cette communication propose une nouvelle methodologie pour mieux controler le rayonnement de pann... more Cette communication propose une nouvelle methodologie pour mieux controler le rayonnement de panneaux plans reflechissants a modulation periodique d'impedance de surface. Il s'agit en particulier de limiter les reflexions parasites associees aux harmoniques de Floquet d'ordre superieur. L'approche s'appuie sur la definition de parametres permettant d'evaluer a priori le potentiel des motifs periodiques candidats et est validee par des simulations electromagnetiques.
2019 13th European Conference on Antennas and Propagation (EuCAP), 2019
This communication addresses the issue of parasitic reflections from reflecting panels using Surf... more This communication addresses the issue of parasitic reflections from reflecting panels using Surface Impedance Modulation (SIM). These reflections are due to Floquet harmonics appearing because of the SIM periodicity. Different SIM panels made of microstrip dipoles are compared at f=8GHz using ANSYS® HFSS®. New metrics are proposed to assess the dipole performance with regards to Harmonic Lobe levels (HLL). Design rules are derived, which permit to mitigate higher order harmonics in unwanted directions.
Journal of Communications Technology and Electronics, 2016
Conventional slotted waveguide antennas are well known and prominently used for many military and... more Conventional slotted waveguide antennas are well known and prominently used for many military and even marketable applications. This is due to their different advantageous electrical and mechanical characteristics. It is also well known that this type of antennas is a typical array of slots with which the width of the main beam can be controlled in only one plane by using a different number of elements in such antennas. Numerous research, discuss the capability of using an array of such antennas in order to narrow down the main beam in both planes and even achieve a scanning phased array. In this paper, a new and broader approach is presented concerning beam width control of the typical configuration of such antennas. This work presents the ability to control the main lobe in both planes using only one slotted waveguide to a certain extent. Different simulation results are considered at the 2.4 GHz frequency demonstrating improved effectiveness in terms of directivity and high gain as well as minimizing the side-lobe level and mechanically controlling the main lobe of the antenna.
2015 Third International Conference on Digital Information, Networking, and Wireless Communications (DINWC), 2015
Antennas are becoming crucial in an increasingly growing number of vital applications, particular... more Antennas are becoming crucial in an increasingly growing number of vital applications, particularly with the emergence of the 3G and 4G generations of communications. Point-to-multipoint configuration is a major interest nowadays; therefore antennas are designed for this purpose where efficiency, size, and cost play a decisive role. The common practice is to refer to the already existing antennas in the market for this sole purpose. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are extremely hard to simultaneously optimize. The purpose of this project is to present a new configuration relying on the use of Slotted Circular Waveguide Antennas, which are initially used in Radar applications, as an ultimate alternative that allows drastically enhancing the ratio of performance versus cost. Moreover, the antenna will be remodeled and designed to function as an enhanced Circular Slotted Waveguide Antenna with optimized directional characteristics with gain above 10 dBi (to be considered as high gain). Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. A prototype was fabricated to measure its parameters and compare them with simulation results. It is still noteworthy to mention that these results matched with an elevated accuracy since the pattern simulated is meshed and modeled to a far extent taking into account all non-ideal characteristics.
2013 13th Mediterranean Microwave Symposium (MMS), 2013
Antennas, nowadays, are used in many systems especially in wireless internet communications and m... more Antennas, nowadays, are used in many systems especially in wireless internet communications and military Radar applications where high power handling capability, high gain along with reliable mechanical characteristics is needed. However, these parameters are very hard to simultaneously optimize, there is always a trade-off in between. In this paper, a Cylindrical Omnidirectional Slotted Waveguide Antenna (COSWA) is presented. The purpose of this paper is to provide an optimized version of circular slotted waveguide antennas by simply selecting the optimum position, number, shape and size of the slots within the waveguide wall. Such configurations are suitable to be used in Wireless internet distributing systems, Military radar applications and even oil drilling devices. Simulation results along with Experimental validations will be conducted at 2.4 GHz frequency demonstrating high effectiveness in terms of directivity and high gain given a reduced cost, simplicity and size.
Dans ce papier, la conception d’un reflecteur diedrique comprime via l'Optique de Transformat... more Dans ce papier, la conception d’un reflecteur diedrique comprime via l'Optique de Transformation est abordee. La hauteur du reflecteur est reduite en utilisant un milieu homogene avec une anisotropie dielectrique. La conception proposee est validee a f0 = 8GHz par des simulations electromagnetiques en utilisant le logiciel COMSOL Multiphysics.
2016 IEEE Middle East Conference on Antennas and Propagation (MECAP), 2016
This research is concerned with controlling the radiation pattern of a sectional cylindrical slot... more This research is concerned with controlling the radiation pattern of a sectional cylindrical slotted waveguide antenna (SCSWA) in both horizontal and vertical planes to make the antenna more directive. In order to cover an area several SCSWAs are used, so the beam should be narrow in the horizontal plane to avoid interference. To control the beam in the vertical plane, the number, the width, and the position of slots could be varied. In this research, the focus is on controlling the radiation pattern in the horizontal plane by changing the concavity of the surface where the slots are placed. A series of simulations were performed on the proposed antenna at a desired frequency of 2.4 GHz, the results showed good control over the antenna's performance.
2016 IEEE Middle East Conference on Antennas and Propagation (MECAP), 2016
In this paper, the design of compressed retrodirective reflectors via transformation optics is ad... more In this paper, the design of compressed retrodirective reflectors via transformation optics is addressed. The proposed method enables a compressed reflector to perform as a classical retrodirective corner reflector while having a much lower profile. Using a simple linear coordinate transformation, the lower profile can be achieved with a TO domain in the reflector consisting of anisotropic homogeneous media. The proposed design is validated at f0=8GHz by full wave electromagnetic simulations. Furthermore, using the Effective Medium Theory approach, the practical feasibility of the involved medium distribution is discussed and verified. The results of the investigations could be of interest in different radar, communication and identification applications.
Journal of Communications Technology and Electronics, 2015
Antennas are becoming crucial in an increasingly growing number of applications namely with the e... more Antennas are becoming crucial in an increasingly growing number of applications namely with the emerging of the wireless internet communications where efficiency, compactness and cost play a decisive role. Nonetheless a major drawback of such solutions is that the aforementioned criteria are hard to simultaneously optimize. In this paper an innovative approach relying on using circularly bent rectangular slotted waveguide antenna as an ultimate alternative is presented that allows drastically enhancing the ratio of performance versus cost and size. Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size.
AIP Advances, Feb 1, 2018
This study proposes a new approach to flatten retrodirective corner reflectors. The proposed meth... more This study proposes a new approach to flatten retrodirective corner reflectors. The proposed method enables compact reflectors via Transformation Optics (TO) combined with Surface Impedance Modulation (SIM). This combination permits to relax the constraints on the anisotropic material resulting from the TO. Phase gradient approach is generalized to be used within anisotropic media and is implemented with SIM. Different reflector setups are designed, simulated and compared for = 8 using ANSYS ® HFSS ® in order to validate the use of such a combination.
2015 Loughborough Antennas & Propagation Conference (LAPC), 2015
2013 2nd International Conference on Advances in Biomedical Engineering, 2013
2015 Third International Conference on Digital Information, Networking, and Wireless Communications (DINWC), 2015
Journal of Communications Technology and Electronics, 2015
Antennas are becoming crucial in an increasingly growing number of vital applications, particu la... more Antennas are becoming crucial in an increasingly growing number of vital applications, particu larly with the emergence of the 3G and 4G generations of communications. Point to multipoint configura tion is a major interest nowadays; therefore antennas are designed for this purpose where efficiency, size, and cost play a decisive role.The common practice is to refer to the already existing antennas in the market for this sole purpose. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are extremely hard to simultaneously optimize. The purpose of this project is to present a new configuration rely ing on the use of Slotted Circular Waveguide Antennas, which are initially used in Radar applications, as an ultimate alternative that allows drastically enhancing the ratio of performance versus cost. Moreover, the antenna will be remodeled and designed to function as an enhanced Circular Slotted Waveguide Antenna with optimized directional characteristics with gain above 10 dBi (to be considered as high gain). Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. A prototype was fabricated to measure its parameters and compare them with simulation results. It is still noteworthy to mention that these results matched with an elevated accuracy since the pattern simulated is meshed and modeled to a far extent taking into account all non ideal characteristics.
INSA de Rennes ; Université Libanaise - Liban, Nov 27, 2018
Antennas are becoming crucial in an increasingly growing number of applications namely with the e... more Antennas are becoming crucial in an increasingly growing number of applications namely with the emerging of the wireless internet communications, military systems like aircrafts, missiles and submarines or even oil drilling systems where efficiency, compactness and cost play a decisive role. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are hard to simultaneously optimize. In this project, an innovative approach relying on using Ring-Shaped Slotted Waveguide Antenna (RSSWA) as a good alternative is presented, that allows enhancing drastically the ratio of performance versus cost and size. Simulation results along with Experimental validations will be carried out at 2.4 GHz frequency and indubitably demonstrating high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. . Index Terms – Slot, waveguide, omnidirectional, radiation efficiency, compactness, pattern, directivity, high gain, RSSWA.
Cette communication propose une nouvelle methodologie pour mieux controler le rayonnement de pann... more Cette communication propose une nouvelle methodologie pour mieux controler le rayonnement de panneaux plans reflechissants a modulation periodique d'impedance de surface. Il s'agit en particulier de limiter les reflexions parasites associees aux harmoniques de Floquet d'ordre superieur. L'approche s'appuie sur la definition de parametres permettant d'evaluer a priori le potentiel des motifs periodiques candidats et est validee par des simulations electromagnetiques.
2019 13th European Conference on Antennas and Propagation (EuCAP), 2019
This communication addresses the issue of parasitic reflections from reflecting panels using Surf... more This communication addresses the issue of parasitic reflections from reflecting panels using Surface Impedance Modulation (SIM). These reflections are due to Floquet harmonics appearing because of the SIM periodicity. Different SIM panels made of microstrip dipoles are compared at f=8GHz using ANSYS® HFSS®. New metrics are proposed to assess the dipole performance with regards to Harmonic Lobe levels (HLL). Design rules are derived, which permit to mitigate higher order harmonics in unwanted directions.
Journal of Communications Technology and Electronics, 2016
Conventional slotted waveguide antennas are well known and prominently used for many military and... more Conventional slotted waveguide antennas are well known and prominently used for many military and even marketable applications. This is due to their different advantageous electrical and mechanical characteristics. It is also well known that this type of antennas is a typical array of slots with which the width of the main beam can be controlled in only one plane by using a different number of elements in such antennas. Numerous research, discuss the capability of using an array of such antennas in order to narrow down the main beam in both planes and even achieve a scanning phased array. In this paper, a new and broader approach is presented concerning beam width control of the typical configuration of such antennas. This work presents the ability to control the main lobe in both planes using only one slotted waveguide to a certain extent. Different simulation results are considered at the 2.4 GHz frequency demonstrating improved effectiveness in terms of directivity and high gain as well as minimizing the side-lobe level and mechanically controlling the main lobe of the antenna.
2015 Third International Conference on Digital Information, Networking, and Wireless Communications (DINWC), 2015
Antennas are becoming crucial in an increasingly growing number of vital applications, particular... more Antennas are becoming crucial in an increasingly growing number of vital applications, particularly with the emergence of the 3G and 4G generations of communications. Point-to-multipoint configuration is a major interest nowadays; therefore antennas are designed for this purpose where efficiency, size, and cost play a decisive role. The common practice is to refer to the already existing antennas in the market for this sole purpose. Nonetheless, a major drawback of such solutions is that the aforementioned criteria are extremely hard to simultaneously optimize. The purpose of this project is to present a new configuration relying on the use of Slotted Circular Waveguide Antennas, which are initially used in Radar applications, as an ultimate alternative that allows drastically enhancing the ratio of performance versus cost. Moreover, the antenna will be remodeled and designed to function as an enhanced Circular Slotted Waveguide Antenna with optimized directional characteristics with gain above 10 dBi (to be considered as high gain). Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size. A prototype was fabricated to measure its parameters and compare them with simulation results. It is still noteworthy to mention that these results matched with an elevated accuracy since the pattern simulated is meshed and modeled to a far extent taking into account all non-ideal characteristics.
2013 13th Mediterranean Microwave Symposium (MMS), 2013
Antennas, nowadays, are used in many systems especially in wireless internet communications and m... more Antennas, nowadays, are used in many systems especially in wireless internet communications and military Radar applications where high power handling capability, high gain along with reliable mechanical characteristics is needed. However, these parameters are very hard to simultaneously optimize, there is always a trade-off in between. In this paper, a Cylindrical Omnidirectional Slotted Waveguide Antenna (COSWA) is presented. The purpose of this paper is to provide an optimized version of circular slotted waveguide antennas by simply selecting the optimum position, number, shape and size of the slots within the waveguide wall. Such configurations are suitable to be used in Wireless internet distributing systems, Military radar applications and even oil drilling devices. Simulation results along with Experimental validations will be conducted at 2.4 GHz frequency demonstrating high effectiveness in terms of directivity and high gain given a reduced cost, simplicity and size.
Dans ce papier, la conception d’un reflecteur diedrique comprime via l'Optique de Transformat... more Dans ce papier, la conception d’un reflecteur diedrique comprime via l'Optique de Transformation est abordee. La hauteur du reflecteur est reduite en utilisant un milieu homogene avec une anisotropie dielectrique. La conception proposee est validee a f0 = 8GHz par des simulations electromagnetiques en utilisant le logiciel COMSOL Multiphysics.
2016 IEEE Middle East Conference on Antennas and Propagation (MECAP), 2016
This research is concerned with controlling the radiation pattern of a sectional cylindrical slot... more This research is concerned with controlling the radiation pattern of a sectional cylindrical slotted waveguide antenna (SCSWA) in both horizontal and vertical planes to make the antenna more directive. In order to cover an area several SCSWAs are used, so the beam should be narrow in the horizontal plane to avoid interference. To control the beam in the vertical plane, the number, the width, and the position of slots could be varied. In this research, the focus is on controlling the radiation pattern in the horizontal plane by changing the concavity of the surface where the slots are placed. A series of simulations were performed on the proposed antenna at a desired frequency of 2.4 GHz, the results showed good control over the antenna's performance.
2016 IEEE Middle East Conference on Antennas and Propagation (MECAP), 2016
In this paper, the design of compressed retrodirective reflectors via transformation optics is ad... more In this paper, the design of compressed retrodirective reflectors via transformation optics is addressed. The proposed method enables a compressed reflector to perform as a classical retrodirective corner reflector while having a much lower profile. Using a simple linear coordinate transformation, the lower profile can be achieved with a TO domain in the reflector consisting of anisotropic homogeneous media. The proposed design is validated at f0=8GHz by full wave electromagnetic simulations. Furthermore, using the Effective Medium Theory approach, the practical feasibility of the involved medium distribution is discussed and verified. The results of the investigations could be of interest in different radar, communication and identification applications.
Journal of Communications Technology and Electronics, 2015
Antennas are becoming crucial in an increasingly growing number of applications namely with the e... more Antennas are becoming crucial in an increasingly growing number of applications namely with the emerging of the wireless internet communications where efficiency, compactness and cost play a decisive role. Nonetheless a major drawback of such solutions is that the aforementioned criteria are hard to simultaneously optimize. In this paper an innovative approach relying on using circularly bent rectangular slotted waveguide antenna as an ultimate alternative is presented that allows drastically enhancing the ratio of performance versus cost and size. Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size.
AIP Advances, Feb 1, 2018
This study proposes a new approach to flatten retrodirective corner reflectors. The proposed meth... more This study proposes a new approach to flatten retrodirective corner reflectors. The proposed method enables compact reflectors via Transformation Optics (TO) combined with Surface Impedance Modulation (SIM). This combination permits to relax the constraints on the anisotropic material resulting from the TO. Phase gradient approach is generalized to be used within anisotropic media and is implemented with SIM. Different reflector setups are designed, simulated and compared for = 8 using ANSYS ® HFSS ® in order to validate the use of such a combination.
2015 Loughborough Antennas & Propagation Conference (LAPC), 2015
2013 2nd International Conference on Advances in Biomedical Engineering, 2013
2015 Third International Conference on Digital Information, Networking, and Wireless Communications (DINWC), 2015