Institute Of Electronics And Telecommunications Of Rennes Ietr

Rennes, France

Institute Of Electronics And Telecommunications Of Rennes Ietr

Rennes, France
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Nikolayev D.,Institute of Electronics and Telecommunications of Rennes IETR | Nikolayev D.,University of West Bohemia | Zhadobov M.,Institute of Electronics and Telecommunications of Rennes IETR | Karban P.,University of West Bohemia | Sauleau R.,Institute of Electronics and Telecommunications of Rennes IETR
2017 11th European Conference on Antennas and Propagation, EUCAP 2017 | Year: 2017

We propose a versatile 434 MHz in-body capsule antenna suitable for ingestible and variety of implantable applications. The low profile conformal antenna is synthesized using a hybrid analytical-numerical approach and optimized for robust operation at 434 MHz inside a 17 mm long biocompatible encapsulation (7 mm diameter). The antenna remains matched below -10 dB in wide range of body tissues (from 42% of muscle electromagnetic properties up to the maximum tissue electromagnetic properties). A realized gain is -22.4 dBi and radiation efficiency reaches 0.4%. The radiation performance of the proposed antenna exceeds most of counterparts whereas its impedance characteristics are more robust. © 2017 Euraap.


Dubois T.,Institute of Electronics and Telecommunications of Rennes IETR | Helard M.,Institute of Electronics and Telecommunications of Rennes IETR | Crussiere M.,Institute of Electronics and Telecommunications of Rennes IETR | Germond C.,Thales Alenia
Eurasip Journal on Wireless Communications and Networking | Year: 2013

Time reversal (TR) is considered as a promising technique for green and multi-user communications thanks to its time and space focusing properties. TR can be viewed as a precoding scheme which can be combined with orthogonal frequency division multiplexing (OFDM) and easily carried out in a multiple transmit antenna context. This paper analyzes the performance of TR for a multiple-input single-output (MISO) OFDM system and provides a comparison with maximum ratio transmission (MRT) and equal gain transmission (EGT) precoding techniques. The analytical performance of the three precoding techniques is derived by computing the capacity and the bit error rate (BER) as a function of the transmit signal-to-noise ratio (SNR). First, the capacity analysis highlights the ability of the TR system to provide higher bit rates than the MRT system at low SNRs, while the capacity of the MRT system is the highest at high SNRs. From the obtained BER analytical expressions, the diversity exploitation of each system is discussed. In particular, it is shown that the TR system only exploits half the available diversity, while the systems using EGT or MRT exploit the full diversity. Hence, contrary to what is expected from the theoretical capacity analysis, the TR system is shown to underperform the other precoding schemes in terms of BER. To overcome such a drawback, the combination of TR with classical adaptive modulation techniques is studied, allowing the achievable throughput to be increased without destroying the focusing properties of TR. It is then observed that TR takes advantage of adaptive modulations and outperforms the other schemes at low SNRs. In this study, analytical results and closed-form expressions of capacity and BER performance are provided and confirmed through Monte Carlo simulations. © 2013 Stolojescu-Crisan and Isar; licensee Springer.


Nikolayev D.,Institute of Electronics and Telecommunications of Rennes IETR | Nikolayev D.,University of West Bohemia | Zhadobov M.,Institute of Electronics and Telecommunications of Rennes IETR | Karban P.,University of West Bohemia | Sauleau R.,Institute of Electronics and Telecommunications of Rennes IETR
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

We propose an approach to increase the operating range and matching stability of in-body ingestible or implantable capsule antennas. It involves using high permittivity biocompatible superstrate on a high-Q narrowband microstrip antenna. In this way, the antenna-body coupling can be significantly reduced, resulting in improved detuning immunity, increased radiation efficiency, and reduced power absorption inside the body. To demonstrate the feasibility of the proposed approach, we designed a mid-ISM band (433 to 434.8) MHz low-profile (85 μm) conformal microstrip antenna loaded with high permittivity ceramic superstrate. We achieved a simulated gain of -20.4 dBi. The radiation efficiency reaches 0.6%, which exceeds the counterparts operating within the same band by at least 3.5 times. The bandwidth is 26 MHz (6%), while the antenna remains matched (S11 < -10 dB) at 434 MHz within a wide range of tissue-equivalent phantoms. To validate the numerical results, we manufactured an antenna prototype and characterized it in terms of reflection coefficient S11. © 2016 European Association of Antennas and Propagation.


Aznabet M.,Abdelmalek Essaadi University | El Mrabet O.,Abdelmalek Essaadi University | Floch J.M.,Institute Of Electronics And Telecommunications Of Rennes Ietr | Falcone F.,Public University of Navarra | Drissi M.,Institute Of Electronics And Telecommunications Of Rennes Ietr
Waves in Random and Complex Media | Year: 2015

In this paper, we report a new design of a compact coplanar waveguide-fed printed antenna with complementary split ring resonator (CSRR). The designed antenna consists of two CSRRs, with same geometrical parameters, printed symmetrically into the top layer. The overall volume of the proposed antenna is only 30 × 20 × 0.8 mm3 (0.58λ0 × 0.39λ0 × 0.015λ0), where λ0 is the wavelength of the simulated resonance frequency. The resonance frequency of the antenna is essentially defined by geometrical parameters of the CSRR, which makes it suitable for various wireless communication systems. The characteristics of the proposed antenna have been investigated using simulation software CST Microwave Studio and experimental results. The measured and simulated results show good agreement, providing a simple and low-cost design. © 2014 © 2014 Taylor & Francis.


Wang H.,Institute of Electronics and Telecommunications of Rennes IETR | Wang H.,European University of Brittany | Allain S.,Institute of Electronics and Telecommunications of Rennes IETR | Meric S.,Institute of Electronics and Telecommunications of Rennes IETR | And 2 more authors.
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2012

The objective of this study is to evaluate the potential of C-band polarimetric multi-angular Radarsat-2 datasets to characterize soil moisture and surface roughness over bare agricultural fields. The polarimetric parameters derived from single angular and dual angular SAR data are examined to analyze the polarimetric sensitivities to bare surfaces. In the case of single angular analysis, the results show that smooth surfaces can be separated from medium rough as well as rough surfaces. Polarimetric parameters SRalpha1, ρhhvv have potentials to characterize soil moisture. In the case of dual angular analysis, the backscattering coefficient differences between two incidence angles Δσ in HH and VV polarization depend negatively on surface roughness and positively on soil moisture. © 2012 IEEE.


Abdul-Nabi S.,Lebanese University | Abdul-Nabi S.,European University of Brittany | Khalil A.,Lebanese University | Khalil A.,European University of Brittany | And 2 more authors.
2013 3rd International Conference on Communications and Information Technology, ICCIT 2013 | Year: 2013

In this paper, we study Network Coding (NC) at switching level. We use novel algorithms and a new header to route coded messages to various destinations. Coding is based on address correlation and decoding is performed only at destination. The main characteristics of our approach is the use of adaptive memory to validate decoding capability at destination and converting multicasted messages to unicasted. We also argue that there are benefits in applying such approach and finally we examine the design of the new added header to hold adaptive memories. © 2013 IEEE.


Khalil A.,European University of Brittany | Khalil A.,Institute of Electronics and Telecommunications of Rennes IETR | Crussiere M.,European University of Brittany | Crussiere M.,Institute of Electronics and Telecommunications of Rennes IETR | And 2 more authors.
Annales des Telecommunications/Annals of Telecommunications | Year: 2013

With the growing demand for new wireless applications accompanied with high expectations for better QoS fulfillment especially for multimedia and real-time applications, the performance of the radio resource management in a multiuser context is ensured by the ability to provide an efficient and optimized spectrum sharing scheme that should respect the wireless channel conditions and satisfy the different users' demands. From the physical layer perspective, metrics such as spectrum efficiency and minimum BER are the most important criteria to be considered. On the other hand, from a user perspective, QoS as well as fairness among the competing users are the main metrics because they determine how much end-users are satisfied and how efficient the available resources are shared among the existing users. Based on the use of the linear precoded orthogonal frequency division multiplexing (LP-OFDM) solution proposed as an evolution of the well-known multiband OFDM (MB-OFDM) solution supported by the WiMedia Alliance for future high-rate ultra-wideband (UWB) systems, the objective of this paper is twofold. First, we study a multiuser optimization spectrum sharing scheme for LP-OFDM systems. Second, based on the optimization study, we define a novel multiple-access solution which jointly considers the frequency resource allocation and the time scheduling for the high-rate LP-OFDM UWB systems. Simulation results demonstrate the efficiency of the use of the LP-OFDM transmission technique in the multiuser spectrum sharing scheme. Besides, the novel multiuser time-frequency sharing scheme shows its capacity to provide a high performance level for high-priority users. © 2012 Institut Mines-Télécom and Springer-Verlag.


Serhir M.,Institute Of Electronics And Telecommunications Of Rennes Ietr | Besnier P.,Institute Of Electronics And Telecommunications Of Rennes Ietr | Drissi M.,Institute Of Electronics And Telecommunications Of Rennes Ietr
IEEE Transactions on Antennas and Propagation | Year: 2010

A method to derive an equivalent radiation source for planar antennas is presented. This method is based on spherical near-field (NF) data (measured or computed) to ascertain an equivalent set of infinitesimal dipoles placed over the main antenna aperture. These produce the same antenna radiation field, both inside and outside the minimum sphere enclosing the antenna. A spherical wave expansion (SWE) of the NF data is written in terms of infinitesimal dipoles using a transition matrix. This matrix expresses the linear relations between the transmission coefficients of the antenna and the transmission coefficients of each dipole. The antenna a priori information are used to set the spatial distribution of the equivalent dipoles. The translational and rotational addition theorems are exploited to derive the transmission coefficients of the dipoles. Once the excitation of each dipole is known, the field at any aspect angle and distance from the antenna is rapidly calculated. Computations with EM simulation data of an antenna array illustrate the reliability of the method. © 2009 IEEE.


Sentucq B.,Institute of Electronics and Telecommunications of Rennes IETR | Sharaiha A.,Institute of Electronics and Telecommunications of Rennes IETR | Collardey S.,Institute of Electronics and Telecommunications of Rennes IETR
2013 7th European Conference on Antennas and Propagation, EuCAP 2013 | Year: 2013

A new electrically small antenna design based on a metamaterial-inspired structure driven by an electrically small monopole antenna is presented. This antenna of λ0/19×λ0/19 size works in the UHF band and offers a simulated efficiency of 75%, with an average maximum gain of 0.86dB and a directivity of 2.12dB in the matched bandwidth of 5.2MHz. This antenna is then used in a compact array of two identical elements in order to achieve a higher directivity. Two arrays are compared: one with two driven elements and a parasitic array with only one of the two elements driven. The design details, simulated and measured radiation characteristics of the antenna system and antenna arrays are reported. © 2013 EurAAP.

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