C. Cheype

Bio: C. Cheype is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Dielectric resonator antenna & Radiation pattern. The author has an hindex of 3, co-authored 4 publications receiving 684 citations.

Directive photonic-bandgap antennas

Abstract: This paper introduces two new photonic bandgap (PBG) material applications for antennas, in which a photonic parabolic reflector is studied. It is composed of dielectric parabolic layers associated to obtain a PBG material. The frequency gap is used to reflect and focus the electromagnetic waves. This device has been designed using a finite-difference time-domain (FDTD) code. FDTD computations have provided the theoretical reflector's directivity. These results are in good agreement with measurements, and it appears that the PBG reflector presents the same directivity as a metallic parabola. A second application uses a defect PBG material mode associated with a metallic plate to increase the directivity of a patch antenna. We explain the design of such a device and propose experimental results to validate the theoretical analysis.

An electromagnetic bandgap resonator antenna

Abstract: This paper introduces a new explanation of the electromagnetic bandgap (EBG) material properties using the study of the EBG structures in the frequency domain and reciprocal space. Once the behavior of such a material is understood, the properties of the EBG are used in order to make an EBG antenna. The antenna is realized with dielectric EBG rods. Its directivity is increased compared to a simple patch antenna. Such a device allows us to obtain a high gain with a very thin structure.

1-D photonic bandgap resonator antenna

Abstract: This paper presents a theoretical method used to realize a 1-D photonic bandgap (PBG) resonator antenna. Studies in the frequency and space domain were made to determine the properties of the material. Then a 1-D PBG resonator antenna was designed, and some characteristics of the antenna were shown as the radiation pattern, the linear, and the circular polarization. The results show that such a device permits us to obtain high gain with a very thin structure. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 312–315, 2001.

Antenne a large bande ou multi-bandes

Abstract: L'invention concerne une antenne a large bande ou multi-bandes pour micro-ondes. Elle comporte un plan reflecteur (R) et au moins un element rayonnant (ER) dispose au voisinage du reflecteur (R). Un assemblage d'elements de materiau BIP a defaut est superpose au plan reflecteur (R) et a l'element rayonnant (ER). Chaque element de materiau BIP a defaut est sensiblement plan, parallele au reflecteur (R) et presente au moins une caracteristique de permeabilite magnetique de permittivite dielectrique et/ou d'epaisseur dans la direction perpendiculaire au reflecteur (R) differente d'un element de materiau BIP a l'autre. L'ensemble forme une cavite resonnante a fuites. Application a la telephonie mobile, ou aux transmissions par voie optique.

Leaky-Wave Antennas

Abstract: This paper gives a basic review and a summary of recent developments for leaky-wave antennas (LWAs). An LWA uses a guiding structure that supports wave propagation along the length of the structure, with the wave radiating or “leaking” continuously along the structure. Such antennas may be uniform, quasi-uniform, or periodic. After reviewing the basic physics and operating principles, a summary of some recent advances for these types of structures is given. Recent advances include structures that can scan to endfire, structures that can scan through broadside, structures that are conformal to surfaces, and structures that incorporate power recycling or include active elements. Some of these novel structures are inspired by recent advances in the metamaterials area.

Artificial magnetic conductor surfaces and their application to low-profile high-gain planar antennas

Abstract: Planar periodic metallic arrays behave as artificial magnetic conductor (AMC) surfaces when placed on a grounded dielectric substrate and they introduce a zero degrees reflection phase shift to incident waves. In this paper the AMC operation of single-layer arrays without vias is studied using a resonant cavity model and a new application to high-gain printed antennas is presented. A ray analysis is employed in order to give physical insight into the performance of AMCs and derive design guidelines. The bandwidth and center frequency of AMC surfaces are investigated using full-wave analysis and the qualitative predictions of the ray model are validated. Planar AMC surfaces are used for the first time as the ground plane in a high-gain microstrip patch antenna with a partially reflective surface as superstrate. A significant reduction of the antenna profile is achieved. A ray theory approach is employed in order to describe the functioning of the antenna and to predict the existence of quarter wavelength resonant cavities.

Leaky‐Wave Antennas

Abstract: This chapter contains sections titled: Introduction History Classification of Leaky‐Wave Antennas Physics of Leaky Waves Radiation Properties of One‐Dimensional Leaky‐Wave Antennas Radiation Properties of Two‐Dimensional Leaky‐Wave Antennas Conclusions Acknowledgment References

Electromagnetic Band Gap Structures in Antenna Engineering

Abstract: Preface 1. Introduction 2. FDTD Method for periodic structure analysis 3. EBG Characterizations and classifications 4. Design and optimizations of EBG structures 5. Patch antennas with EBG structures 6. Low profile wire antennas on EBG surfaces 7. Surface wave antennas Appendix: EBG literature review.

A novel compact electromagnetic-bandgap (EBG) structure and its applications for microwave circuits

Abstract: A novel electromagnetic-bandgap (EBG) structure in a fork-like shape is investigated. This structure has an extremely compact size. A comparison has been carried out between the new structure and the conventional mushroom-like EBG structure. Simulations and experimental results have verified that the area of the fork-like structure is less than 40% of the latter. The presented structure also provides an additional degree of freedom to adjust the bandgap position, which is applied to design a novel reconfigurable multiband EBG structure. Several application examples have been demonstrated, including a double-element microstrip antenna array with low mutual coupling, notch-type antenna duplexer, and steerable array with a linearly discrete beamsteering of 20/spl deg/ in steps of 10/spl deg/ at 2.468 GHz.