Etude et réalisation d'une antenne oscillatrice à 40 GHz

L'objet de cet article est l'étude de l'association d'une antenne multi-couche avec un oscillateur. Les antennes imprimées multi-couche sont favorables à l'intégration de composants actifs. Habituellement, les oscillateurs sont conçus à partir de composants actifs tels que les transistors ou les diodes. L'antenne oscillatrice imprimée est une solution technologique pour la réalisation de systèmes de communication légers et faible coût. Un point important est la possibilité de changer la fréquence d'émission de l'antenne pour permettre des communications numériques. Une méthode de conception est présentée et les performances à 40 GHz d'un prototype sont mentionnées afin de valider le fonctionnement en bandes millimétriques de l'antenne oscillatrice imprimée

Frequency tunable antenna for digital video broadcasting handheld application

International audienceIn this paper, we present a frequency tunable antenna suitable for Digital Video Broadcasting Handheld applications. Due to the narrow operating frequency band of the antenna derived from a monopole coupled loop antenna, a tuning system has been proposed to sweep the narrow band on a large frequency range in order to cover the DVB-H frequency bandwidth [470-702] MHz. We provide results of this antenna mounted on a circuit board simulating a terminal handset

Superstrate Antennas for Wide Bandwidth and High Efficiency for 60 GHz Indoor Communications

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A 2D Synthetic Aperture Radiometry Demonstrator by Switching Strategy at X band

International audienceThe broad topic of the presented paper consists in the research on novel methods in the field of microwave imaging, in particular the so-called passive microwave / millimeter-wave imaging, which is also referred to radiometric imaging. This study focuses on proximity range applications such as concealed objects detection, human body screening, etc. The aim is to design a low cost and compact fully electronic passive imaging system suitable for short-range 2D imaging applications, and study the necessary devices for the implementation of a complete demonstrator. In this study, a new approach based on the use of a switch sub-matrix strategy has been adapted into a complete antenna system at X band. The main objective of this prototype is to validate this approach experimentally. Image quality is examined by using the interferometric aperture synthesis technique and G-matrix calibration imaging algorithms. The spatial resolution is measured by using the emission from noise source and is compared with theory

A synthetic aperture interferometric radiometer test at X-band for potential improvements at W-band

International audienceThe broad topic of the presented paper consists in the research on novel methods in the field of microwave imaging, in particular the so-called passive microwave / millimeter-wave imaging, which is also referred to radiometric imaging. This study focuses on proximity range applications such as concealed objects detection, human body screening, etc. The aim is to design a low cost and compact fully electronic passive imaging system suitable for short-range 2D imaging applications, and study the necessary devices for the implementation of a complete demonstrator. In this study, a new approach based on the use of a switch sub-matrix strategy has been adapted into a complete antenna system at X band. The main objective of this prototype is to validate this approach experimentally. Image quality is examined by using the interferometric aperture synthesis technique and G-matrix calibration imaging algorithms. The spatial resolution is measured using the emission from noise source and compared with theory

A 2D Synthetic Aperture Radiometry Demonstrator by Switching Strategy at X band

International audienceThe broad topic of the presented paper consists in the research on novel methods in the field of microwave imaging, in particular the so-called passive microwave / millimeter-wave imaging, which is also referred to radiometric imaging. This study focuses on proximity range applications such as concealed objects detection, human body screening, etc. The aim is to design a low cost and compact fully electronic passive imaging system suitable for short-range 2D imaging applications, and study the necessary devices for the implementation of a complete demonstrator. In this study, a new approach based on the use of a switch sub-matrix strategy has been adapted into a complete antenna system at X band. The main objective of this prototype is to validate this approach experimentally. Image quality is examined by using the interferometric aperture synthesis technique and G-matrix calibration imaging algorithms. The spatial resolution is measured by using the emission from noise source and is compared with theory

Dielectric Resonator Nantennas for Optical Communication

Dielectric resonator antennas (DRA) are ceramic based materials that are nonmetallic in nature. They offer high permitivity values (εr: 10-100). DRAs? have made their mark in various applications specially in the microwave and millimeter wave (MMW) spectrum, and are making encouraging progress in the THz band, because of their low conduction losses and higher radiation efficiencies compared to their metallic counterparts. With the advancements in nano fabrication, metallic antennas designed in the THz band have taken an interest. These antennas are termed as optical antennas or nantennas. Optical antennas work by receiving the incident electromagnetic wave or light and focusing it on a certain point or hot spot. Since most of the antennas are metallic based with Noble metals as radiators, the conducting losses are huge. One solution that we offer in this work is to integrate the nantennas with DRs. Two different DR based designs, one triangular and other hexagonal, are presented. Both the antennas operate in the optical C-band window (1550 nm). We design, perform numerical analysis, simulate, and optimize the proposed DR nantennas. We also consider array synthesis of the proposed nantennas in evaluating how much directive the nantennas are for use in nano network applications

Investigating the Influence of Rotating Steel Platform in the RCS Measurement of Vehicles At 22-26 GHz for Automotive Radar Application

International audienceThis paper investigates the influence of rotating applications, such as ACC (Adaptive Cruise Control) or FCW steel platform in the RCS (Radar Cross Section) measurement of (Forward Collision Warning). vehicles at 22-26 GHz for automotive radar application. Across several measurement steps, we compare different RCS measurement results in order to eliminate the undesired RCS contribution caused mainly by the rotating steel platform. We demonstrate that when it is difficult or impossible to use microwave absorbers on the steel platform, an alternative scan (symmetry of vehicle) of target vehicle, the VUT should method can be applied. Finally, with the help of 2D radar image be positioned on a rotating steel platform. The RCS measurement configuration could be described as follows. As in a real road cruising situation, we carry out RCS measurements in outdoor conditions. Secondly, considering the weight of VUT, and the need of a continuous 180° azimuth post processing, we can also identify and separate the RCS contribution of each element (vehicle, steel platform, ground/multipath/clutter) in the hologram image, and therefore obtain the pure RCS distribution of the tested vehicle

Investigating the Influence of Rotating Steel Platform in the RCS Measurement of Vehicles At 22-26 GHz for Automotive Radar Application

International audienceThis paper investigates the influence of rotating applications, such as ACC (Adaptive Cruise Control) or FCW steel platform in the RCS (Radar Cross Section) measurement of (Forward Collision Warning). vehicles at 22-26 GHz for automotive radar application. Across several measurement steps, we compare different RCS measurement results in order to eliminate the undesired RCS contribution caused mainly by the rotating steel platform. We demonstrate that when it is difficult or impossible to use microwave absorbers on the steel platform, an alternative scan (symmetry of vehicle) of target vehicle, the VUT should method can be applied. Finally, with the help of 2D radar image be positioned on a rotating steel platform. The RCS measurement configuration could be described as follows. As in a real road cruising situation, we carry out RCS measurements in outdoor conditions. Secondly, considering the weight of VUT, and the need of a continuous 180° azimuth post processing, we can also identify and separate the RCS contribution of each element (vehicle, steel platform, ground/multipath/clutter) in the hologram image, and therefore obtain the pure RCS distribution of the tested vehicle

Compact Dual-Linear Polarized Wideband Antenna for VHF/UHF band.

International audienceA new compact dual-linearly polarized ultrawideband (UWB) antenna for VHF/UHF applications is proposed on this letter. The antenna is miniaturized thanks to inductive loading and lumped resistances. In addition, to reduce back radiation and to optimize the impedance matching at low frequencies, a ferrite layer is placed close to the radiating element. This antenna provides broadband characteristics and unidirectional radiation patterns over the whole bandwidth with a length and a height respectively limited to 6 LF l and 13 LF l , where LF l is the wavelength at the lowest frequency of the operating band. Simulations and measurements are found to be in good agreements