An Ultra-wideband Battery-less Positioning System for Space Applications

An ultra-wide bandwidth (UWB) remote-powered positioning system for potential use in tracking floating objects inside space stations is presented. It makes use of battery-less tags that are powered-up and addressed through wireless power transfer in the UHF band and embed an energy efficient pulse generator in the 3-5 GHz UWB band. The system has been mounted on the ESA Mars Rover prototype to demonstrate its functionality and performance. Experimental results show the feasibility of centimeter-level localization accuracy at distances larger than 10 meters, with the capability of determining the position of multiple tags using a 2W-ERP power source in the UHF RFID frequency band.Comment: Published in: 2019 IEEE International Conference on RFID Technology and Applications (RFID-TA

A low-cost combination for phased array and ESPAR antenna

a low-cost antenna system with high directivity is presented, with possibility of shaped beam in the vertical plane and beam switching in the horizontal plane, ensuring full 360 degrees coverage. The proposed antenna provides a higher directivity than the pattern of a regular Electronically Steerable Parasitic Antenna Radiators (ESPAR) while remaining much simpler than a phased array. The antenna system is made of two concentric rings, each consisting of 6 elements. Only three elements are active at a given time, the others are terminated with the reactive loads. The feeding and command structures are particularly simple. The proposed antenna is fabricated and measured for its performanc

Evaluation of a UWB positioning array with the help of a network analyzer

We presented a technique for the evaluation of positioning with the help of a network analyser, and the link between ambiguity error and bandwidth has been provided. Later work will focus on the compensation of the effects of mutual coupling between array elements.Anglai

Steerable antenna and method for controlling said steerable antenna

Steerable antenna (1) comprising: a first antenna group comprising M antenna elements (5), a second antenna group comprising N antenna elements (5), said N antenna elements (5) surrounding the M antenna elements (5) of first antenna group, switching means (100) coupled to the N antenna elements (5) of second antenna group and a controller (110) programmed for sequentially switching to be active and at different times successive antenna subgroups of second antenna group, while switching at same different times other antenna elements (5) of same second antenna group to be passively terminated in different possible loads. The steerable antenna (1) also comprises L inner termination groups (215) and L inner termination switches (205), 1 ≤ L ≤ M, allowing modifying the termination loads of the antenna elements (5) of first antenna group

Metasurface Antennas for FMCW Radar

Two planar metasurface (MTS) antennas are designed to produce a pattern with optimal illumination in a radar scenario, given the a priori known path of the targets. The antennas are extremely flat, thin, with a monopole feed integrated in the plane of the structure. The monopole serves as a surface-wave (SW) launcher illuminating the slab. The excited SW progressively leaks after interacting with the MTS, forming a radiation pattern designed to cover uniformly a portion of road in a given scenario. The realized antennas radiation patterns are experimentally validated. The MTSs are then deployed in a frequency-modulated continuous wave (FMCW) radar system. The experiments showed that the echo of the targets in the range-Doppler map does not statistically depend on the distance between the target and the radar, while a clear range dependence is observed when classical patch array antennas are used. That means, given the capability to engineer a particular shape for the radiation pattern and the interest for simultaneously detecting small and big targets, the MTS antennas allow one to better resolve a small and distant target, next to a big and close one

Efficient Evaluation of Energy Focusing Based on Eigen-Beamforming

We provide an efficient Method-of-Moments analysis of 2D fields radiated in a typical indoor environment which is applied to the wireless power transfer from a multiple-antenna access point to multiple devices. These simulations allow the computation of the correlation matrix obtained at the access point array when several devices are active. Power focusing capabilities from the same array are then analyzed, including multipath effects. This technique is based on the eigen-analysis of the correlation matrix measured at the access point and presents similarities with time reversal

A prototype 2D direction finding system with passive RFID tags

This paper presents a prototype direction of arrival system designed to locate passive RFID (Radio Frequency Identification) tags in a commercial warehouse environment. The system design is discussed with focus on a MUSIC based algorithm designed to cater for multiple reflections. Special emphasis is placed on the results of a trial of the system in a warehouse.Anglai

Cinq générations de chips UWB (Ultra-Wide-Band) pour la géo-localisation et la transmission de données à très basse consommation

La technologie Ultra-Wide-Band ou UWB de localisation et transmission de données sans fil, par des trains de pulses très courts (< 2 ns) dans une bande de plus de 500 MHz entre 3 et 10 GHz, refait surface dans un grand nombre de scénarios d'applications à très faible consommation de puissance (cfr. annonces récentes de Apple, NXP, VW ... ou encore les consortiums industriels Fira ou UWB Alliance). La présentation visera à réaliser une synthèse des avantages uniques de l'UWB par rapport aux autres solutions radio-fréquence. Les possibilités et difficultés d'implémentation sur Si seront discutées sur base d'essais et de résultats de cinq générations de chips expérimentés à l'UCL et visant d'une part, les localisation et transmission à faible taux de données, et d'autre part, des implémentations à très hauts taux de données. L'extension et les limites d'efficacité pour atteindre les 5 Gbps et le 1 pJ/pulse seront abordées

Testbed for IR-UWB based ranging and positioning: Experimental performance and comparison to CRLBs

In this paper we describe a testbed for impulse radio ultra wideband based ranging and positioning. We show the characteristics of the generated, transmitted and received pulses. We consider both the maximum likelihood estimator and a threshold-based estimator for the estimation of the time of arrival. We measure the variances for ranging and positioning and compare them to the Cramer-Rao lower bounds for range and position estimation. We discuss the impact of both false multipath component detection and false sidelobe detection on the estimation accuracy. The obtained variances are close to the Cramer-Rao lower bounds when the mainlobe of the first multi-path component is detected. In realistic multipath environments we can use a threshold-based time of arrival estimator in order to detect the first multipath component which may be missed by the maximum likelihood estimator. We show also that the errors on positioning due to false multipath component and sidelobe detection can be highly mitigated by increasing the number of receivers. For a radiated energy of 8.1 pJ and a distance of 5 meters between the transmit and receive antennas, the obtained accuracy is in the order of one centimeter.Anglai