Papers by Yacouba Coulibaly
UWB-SIMO channel capacity in an underground mine
This paper presents an evaluation of the ultra-wideband (UWB) channel capacity in an underground ... more This paper presents an evaluation of the ultra-wideband (UWB) channel capacity in an underground mine. A measurement setup was established to measure the channel frequency response both in LOS and NLOS. The measurements were performed at level -70 m in an experimental gold mine. The SISO (single input single output) channel capacity was first determined, followed by the SIMO (single input multiple output) capacity with receiving antennas. The measurements results reveal that the channel capacity can support high data rates. Also, it decreases with the distance between transmitter and receiver. The result shows also that increase of the capacity of a SIMO channel is not linear with the number of receiving antennas.
Design of a Broadband Hybrid Dielectric Resonator Antenna for X-band Applications
Journal of Electromagnetic Waves and Applications, 2006
ABSTRACT
Design of a mm-wave broadband CPW-fed stacked dielectric resonator antenna for underground mining communication
2010 IEEE Antennas and Propagation Society International Symposium, 2010
In this paper, a new design of a stacked rectangular resonator for millimeter underground communi... more In this paper, a new design of a stacked rectangular resonator for millimeter underground communication is proposed. A coplanar waveguide is used as a feeding scheme. A CPW feed is better than the microstrip one because it has low radiation loss at millimeter-wave bands, less dispersion, and the ease of combining active device to form an active array. Numerical results,
Comparative study of gain enhancement of a Dielectric Resonator antenna using three superstrates for millimeter-wave applications
Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
ABSTRACT In this paper, a comparative study of three high gain hybrid antennas with different sup... more ABSTRACT In this paper, a comparative study of three high gain hybrid antennas with different superstrates is presented. The three superstrates are a dielectric slab, a frequency selective surface (FSS) with square ring elements and a dielectric slab, and a FSS with strip dipole. A hybrid Dielectric Resonator antenna (DRA) is the excitation source. This antenna gives a good impedance bandwidth over the entire ISM band (57 GHz- 64 GHz). CST Microwave Studio software package is used to investigate the antennas. The input impedance, the gain, and the far field patterns have been presented. It is observed that the electromagnetic characteristics of a dielectric resonator antenna (DRA) can be enhanced by using different superstrates. The gain can be improved to near 16 dBi. And a gain of 11 dB over the entire ISM band have been achieved.
Large-scale characterization of an underground mining environment for the 60 GHz frequency band
2012 International Conference on Wireless Communications in Underground and Confined Areas, 2012
ABSTRACT In order to improve the mining communication applications such as video with high data r... more ABSTRACT In order to improve the mining communication applications such as video with high data rates, a characterization of the underground mining channel was done. The use of the IEEE.802.15.3c standard with an OFDM modulation scheme for the 60 GHz can allowobtaining a data rate range from 31.5 Mbps to 5.67 Gbps. This paper provides the propagation characteristics of the mine, which is a complex electromagnetic environment, necessary to the deployment of networks in the IEEE.802.15.3c or the IEEE.802.11ad standard. The experimental results were obtained during an extensive measurement campaign over a frequency range of 61 GHz to 63 GHz in an underground mining environment. These results allow the extracting of the large scale parameters such as the path loss exponent which help to design wireless communication systems. The line of sight (LOS) measurements were performed in the middle of the gallery. Finally, a comparison of the results obtained in a mining environment and in a laboratory is done. The path loss exponents are less than 2 in both scenarios as the environments have dense concentration of scatterers.
Progress In Electromagnetics Research C, 2016
This article focuses on the development of a high gain, broadband, circularly polarized Electroma... more This article focuses on the development of a high gain, broadband, circularly polarized Electromagnetic Band Gap (EBG) antenna operating at 60 GHz. The designed antenna is configured with a superstrate based on a frequency selective surface (FSS) placed in front of a cross dielectric resonator antenna (XDRA), installed into a ground plane, which acts as an excitation source. A fast Leaky-Wave approach based on transverse equivalent network (TEN) is used to deduce analytical radiation patterns formulas of the proposed antenna. The proposed analytical model was implemented and verified by a comparison with both numerical and experimental results. The reported results showed very satisfactory performances with an achievable impedance bandwidth (S 11 < -10 dB) of 11.7% from 56 to 63 GHz, an axial-ratio bandwidth (AR < 3 dB) of 5.4% from 58.9 to 62.1 GHz and a stable gain of 16.7 dBi within the passband. A good agreement among analytical, numerical and measured results is successfully achieved and falls well within initially set specifications.
Wideband Impedance Bandwidth Hybrid Dielectric Resonator Antenna for X-Band Applications
2006 IEEE Antennas and Propagation Society International Symposium, 2006
A dielectric resonator antenna (DRA) is one of several promising efficient radiating structures [... more A dielectric resonator antenna (DRA) is one of several promising efficient radiating structures [1], it has been proposed for applications at microwave and millimeter-wave bands. Different reports in open literature show that DRAs are potentially attractive because of their low ...
High gain cylindrical dielectric resonator with superstrate for broadband millimeter-wave underground mining communications
2010 14th International Symposium on Antenna Technology and Applied Electromagnetics & the American Electromagnetics Conference, 2010
This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underg... more This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underground communications systems. The proposed antenna is composed of a superstrate, an aperture coupled feed, an intermediate substrate and a cylindrical dielectric resonator. This antenna is designed to cover the ISM frequency band (57 GHz-65 GHz). This antenna was numerically designed using CST microwave Studio simulation software
High gain rectangular dielectric resonator for broadband millimeter-waves underground communications
2011 24th Canadian Conference on Electrical and Computer Engineering(CCECE), 2011
This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underg... more This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underground communications systems. The proposed antenna is composed of a superstrate, a coplanar waveguide feed, and a rectangular dielectric resonator. This antenna is designed to cover the ISM frequency band at 60 GHz ( 57 GHz-65 GHz). This antenna was numerically designed using CST microwave Studio simulation
Design of a single circular soft surface applied to an aperture fed Dielectric Resonator antenna for gain and bandwidth improvement
Antennas and Propagation Society International Symposium, 2011
In this paper, a novel design of a new broadband and high gain hybrid antenna is presented. The p... more In this paper, a novel design of a new broadband and high gain hybrid antenna is presented. The proposed antenna structure consists of a Dielectric Resonator (DR), an intermediate substrate a microstrip fed slot, and a circular soft surface. With the integration of these different elements, a wide bandwidth response and a high gain are achieved. The cylindrical soft structure
This paper describes the small scale performances of a 60 GHz channel in an underground mine and ... more This paper describes the small scale performances of a 60 GHz channel in an underground mine and in an indoor laboratory using the same channel sounder. The frequency domain channel measurements have been carried out in the 59 GHz to 61 GHz frequency band. Based on the measurements, the two environments are characterized and compared in terms of delay spread, coherence bandwidth. The values of the delay spread are less than 3 ns for both environments. Finally a relationship between the delay spread and the coherence bandwidth is found for both scenarios.
Acquisition of EM propagation parameters onboard trains at UHF frequencies
This paper reports numerical results for the characterization of the propagation channel in a tra... more This paper reports numerical results for the characterization of the propagation channel in a train. Since the availability of a train to carry out measurements is not always easy, particularly when many changes must be done, a simulation tool provides a useful and reliable mean for the evaluation of the propagation characteristics of this complex and highly fluctuating channel. In order to benefit from previous results, the various existing softwares for complex electromagnetic fields environments simulations were fully searched and one that seems best suited has been retained for these computations. The results presented here are original, preliminaries and our approach provides a basis for study the propagation of waves in a very complex environment consisting of different electromagnetic fields like a train.
New hybrid design for a broadband high gain 60-GHz Dielectric Resonator Antenna
Underground mines is a special environment which features severe multipath fading and high attenu... more Underground mines is a special environment which features severe multipath fading and high attenuation rate requiring that antennas have low profile, simple structure, polarization diversity, directivity and high gain. A new broadband and high gain stacked pyramid Dielectric Resonator Antenna (DRA) with a superstrate has been designed for this particular application. The proposed antenna is composed of a superstrate, an aperture coupled feed, a stacked pyramid dielectric resonator and FSS-metallic strips stacked on the lower side of the superstrate. This antenna is designed to cover the unlicensed ISM frequency band at 60 GHz (57 GHz-65 GHz). To analyze the proposed antenna, numerical simulations is carried out with CST microwave studio, which is based on the finite integration method. For comparison and validation of the optimized results, Ansoft HFSS based on the finite element method is also used.
MIMO channel characterization at 2.4 GHz in underground gold mines
2011 IEEE International Symposium on Antennas and Propagation (APSURSI), 2011
Abstract This paper deals with several aspects relative to the Multiple-Input Multiple-Output (MI... more Abstract This paper deals with several aspects relative to the Multiple-Input Multiple-Output (MIMO) propagation channel. Measurement campaigns, made in former gold mine at 2.4 GHz, have been analyzed to obtain the relevant statistical parameters of the channel. ...
Design of a high gain hybrid dielectric resonator antenna for millimeter-waves underground applications
2011 IEEE International Symposium on Antennas and Propagation (APSURSI), 2011
This paper presents a new broadband and high gain dielectric resonator antenna for millimeter-wav... more This paper presents a new broadband and high gain dielectric resonator antenna for millimeter-wave underground communications systems. The proposed antenna is composed of a microstrip feed, a cylindrical dielectric resonator, and multiple metallic strips stacked to a superstrate. This antenna is dedicated for the 60 GHz frequency band. Results show that the antenna has great performances especially in terms of
A dielectric resonator antenna mounted on a conformal structure at 60 GHz
2011 IEEE International Symposium on Antennas and Propagation (APSURSI), 2011
... [6] Qinjiang Rao, Tayeb A. Denidni and Abdel R. Sebak, A hybrid resonator antenna suitable f... more ... [6] Qinjiang Rao, Tayeb A. Denidni and Abdel R. Sebak, A hybrid resonator antenna suitable for wireless communication applications at 1.9 and 2.45GHz, IEEE Antennas and Wireless Propagation Letters, pp. July 2005. ... 57, no. 10, October 2009. [11] Y. Coulibaly, M. Nedil, TA ...
High gain cross DRA antenna array for underground communications
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
ABSTRACT This paper presents the design of a high gain cross DRA array antenna (AXDRA) with a nov... more ABSTRACT This paper presents the design of a high gain cross DRA array antenna (AXDRA) with a novel feeding method based on microstrip transmission line for millimeter-wave operation. Simulation results shows that the AXDRA achieves an impedance bandwidth from 57.5 GHz to 63 GHz covering ISM band, and gives an appreciable gain of 15.5 dBi, found to be stable within the passband. The size of the whole antenna structure is about 25mm×25mm and is therefore small enough to be used in underground communications systems. The simulation process was done using Computer Simulation Technology (CST) Microwave Studio.
Radio-wave propagation into an underground mine environment at 2.4 GHz, 5.8 GHz and 60 GHz
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
ABSTRACT In this paper, an overview of the overall channel characterizations for wireless communi... more ABSTRACT In this paper, an overview of the overall channel characterizations for wireless communication systems in underground mines is presented. Such environments, because of the very nature of the mining operation, the complexity of the systems, and the procedures and extraction methods of the minerals are considered to be dangerous, hazardous and aggressive. Radio signals suffer from strong attenuations due to reflection, diffractions and scatterings in this complex transmission medium. The transmitted radio signals are therefore subject to different impairments and distortions. Moreover, for the deployment of a wireless network, the choice of the operation frequency band, which has a major impact on the planning and the dimensioning, is as important as the deploying environment. Propagation measurements were carried out at 2.4 GHz, 5.8 GHz and 60 GHz. These frequencies were targeted because they are commonly used for different wireless communication applications. This paper summarizes different findings on the propagation characteristic parameters such as the path loss, outage probability, delay spread and the coherence bandwidth. This the first time, to our knowledge, that a comparison of the operating frequency effects in an underground mine is reported.
Gain and bandwidth improvement of an aperture coupled cylindrical dielectric resonator antenna using an EBG structure
2009 IEEE Antennas and Propagation Society International Symposium, 2009
Dielectric Resonator antennas are one of the foremost components that have been fundamentally use... more Dielectric Resonator antennas are one of the foremost components that have been fundamentally used in several communication systems operating at microwave and millimeter-wave bands [1]. In microwave oscillators and filters, dielectric resonators are used because of their ...
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Papers by Yacouba Coulibaly