Time filter

Source Type

Villeneuve R.,Princess Grace Hospital Center | Cueille M.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Arnaud-Cormos D.,CNRS XLIM Research Institute, Limoges | David J.-F.,Thales Alenia | And 2 more authors.
IEEE Transactions on Terahertz Science and Technology | Year: 2015

The output power of backward wave oscillators and carcinotrons decrease considerably at high frequencies. This drop in power can be due to the increase in losses and manufacturing defects in their delay lines. In this study, we present measurement methods and setups developed for the characterization of delay-line performance. The developed methods were validated on two scaled-down models of a TH4229 carcinotron operating in frequency bandwidths around 10 and 100 GHz. Measurements of losses and dispersion diagrams were made using two different wave couplings with propagating waveguides and radiating horn antennas. Electromagnetic simulations were performed using finite-difference time-domain (FDTD) code. For both delay lines, the results obtained from measurements with different couplings presented a very good level of consistency with simulations. The measured losses, normalized per delay line elementary cell, were 0.04 and 0.12 dB/cell at 9.5 and 95 GHz, respectively. Accordingly, the normalized ohmic losses were extrapolated at THz frequencies and at 0.95 THz, 0.38 dB/cell was obtained. As a first approximation, only the skin-effect ohmic losses were considered. The ability to characterize delay lines using radiating coupling was demonstrated. © 2011-2012 IEEE. Source

Dussopt L.,CEA Grenoble | Kaouach H.,CEA Grenoble | Lanteri J.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Sauleau R.,CNRS Institute of Electronics and Telecommunications, Rennes
Radioengineering | Year: 2011

This paper presents the design and demonstration of two circularly-polarized transmit-arrays operating in the 60-GHz band and generating a broadside beam and a 30°-tilted beam respectively. These arrays have a fairly simple structure with only three metal layers and are fabricated with a standard printed-circuit board technology. The simulated results show the performances of the unitcells as well as the whole arrays, and detail their power budget. The experimental results in V-band are in very good agreement with the simulations and demonstrate very satisfactory characteristics. Power efficiencies up to 53.7% are reached with a 1-dB gain-bandwidth up to 9.1%, and low cross-polarization level. Source

Fourquin O.,Aix - Marseille University | Bourdel S.,Aix - Marseille University | Gaubert J.,Aix - Marseille University | Vauche R.,Aix - Marseille University | And 6 more authors.
IEEE Transactions on Components, Packaging and Manufacturing Technology | Year: 2013

In this paper, a low power and low cost ultra wideband impulse radio transmitter is presented. The transmitter includes a pulse generator integrated in a 0.13-μ m standard CMOS technology and an antenna printed on the chip carrier. The board is manufactured with Roger 4003 laminate substrate and has a total area of 50 mm ×,18 mm. The transmitter provides 1.4 V peak to peak Federal Communications Commission compliant pulses at antenna input for data rates up to 36 Mb/s in an on-off keying modulation scheme. The transmitter's power consumption is 12 mW at 1.2-GHz pulse repetition frequency and the energy consumption is 10 pJ per pulse. A 365-mV peak voltage emitted pulse is measured in an anechoic room at 0.8 m range with a receiver, including a horn antenna (8.3 dBi), a LNA (32 dB), and a 12-GHz real time oscilloscope. © 2011-2012 IEEE. Source

Jacquemod G.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Nowak M.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Nowak M.,CEA Grenoble | Colinet E.,CEA Grenoble | And 2 more authors.
Sensors and Actuators, A: Physical | Year: 2010

This paper presents an inductive telemetry platform system for the continuous, real-time and simultaneous remote measurement in harsh environment. First, a SOL (self-oscillating loop) topology for the remote interrogation of wireless battery-less passive sensors is described. This system uses a capacitive sensor configured as an LC-tank whose resonant frequency shifts with the physical measurement. Such a system is generally based on an impedance analyzer in order to measure this frequency shift. In fact, if you increase the distance between the sensor and the reader, the sensibility is not sufficient to use the SOL technique. To overcome this issue, an anti-resonance cancellation, realized with a simple RC cell, is implemented. However, this architecture is dedicated only for a single capacitive sensor. Second, based on an efficient algorithm used for system identification purpose, a readout unit for multiple sensors is proposed. The overall performances of these architectures are analyzed with respect to coupling factor and sensor parameters. Using these two approaches, tests show promising results at mutual coil distances up to 5 cm. © 2010 Elsevier B.V. All rights reserved. Source

Addaci R.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Diallo A.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Diallo A.,Orange S.A. | Luxey C.,Orange S.A. | And 6 more authors.
IEEE Antennas and Wireless Propagation Letters | Year: 2012

In this letter, an innovative technique is proposed to enhance the port-to-port isolation of two closely spaced dual-band radiating elements in the WLAN 2.4-2.5-GHz and 5.15-5.825-GHz frequency bands. This broadband technique consists in inserting an optimized parasitic element between the two antennas of a multiple-input-multiple-output (MIMO) set-top box. High port-to-port isolation is obtained, and the computation of the diversity performance shows suitability for enhanced diversity and MIMO applications. © 2006 IEEE. Source

Discover hidden collaborations