Flexible monolithic ultra-portable ground penetrating radar using inkjet printing technology

Flexible monolithic ultra-portable ground penetrating radar using inkjet printing technology A Ground Penetrating Radar (GPR) performs nondestructive detection of buried objects, or subsurface imaging by transmitting electromagnetic waves and detecting and analyzing the reflections. The main challenge of GPR is the reduction in detection range due to the severe signal attenuation that is caused by subsurface conductivity that becomes more severe at high frequencies. In order to increase the detection range, GPR uses lower frequencies than non-GPR radars and thus requires larger antennas that may limit system portability. Most GPR systems use impulse radars however the FMCW (frequency modulated continuous wave) radar can provide some advantages such as frequency versatility, reduced system maintenance and improved range resolution. Frequencies below 1 GHz were initially uncommon in short-range FMCW radars but are now finding their way back in systems such as ultra-wideband (UWB) ground penetrating radars for mine detection and as well as other applications. When measurements are performed on vehicles, large antenna fixtures are not a problem. Portability, however, can become an issue in geophysical studies or emergency work in which one may need to transport the system through rugged, unexplored and/or hazardous locations without vehicle access and perform measurements. Inaccessible environments may require climbing up and down, squeezing through, jumping over, crawling under, maneuvering through or swimming through obstacles (mountains, caves, lakes, rocky areas). In addition to transportation, rapid system setup is critical in difficult conditions such as freezing temperatures or extreme heat where exposure time is costly and limits measurement time. One solution to enhance the portability and deployability of a GPR system for wide area rugged measurements is to realize a complete system on a continuous substrate that is rollable around a reasonably small radius and storable in a scroll or poster-like fashion for easy backpack transportation. Electronics that can flex and bend have already used in military applications and for outdoor sporting gear. Currently, there are a few types of technology available to realize flexible electronics that have been a major topic of research, each with different levels of integration. Inkjet printing technology offers a cost effective, versatile and efficient method for realizing flexible devices. In this work a classical FMCW radar system is designed and an effort is made, for the first time, to apply inkjet printing technology to a radar system. The system is referred to as a portable monolithic radar system in which all actives, passives and antenna are meant to share the same continuous rollable substrate. In doing this, a medium level of integration is used to investigate limits of system complexity, resolution and ultra miniaturization for tight rollability. Various design challenges of a large system are overcome that will hopefully give insight to new designs as the integration level using inkjet printing technology increases

Novel liquid and broadband circularly-polarized antennas for wearable biomonitoring applications

The explosive growth of the biosensors and health-related wearable monitoring devices has accentuated the need for miniaturized, high-efficiency conformal bio-modules that can operate over a wide range of frequencies, while they can be integrated in wearable and lightweight configurations. One of the major issue for the implementation of Wireless Body Area Networks (WBAN) is the very limited range of commonly used metal antennas. Due to the high dielectric constant between the metal antenna material (as well as the metal-based circuitry) and the mostly "ionized-water" human body parts, the near-field gets significantly disturbed, while local reflections due to the dielectric mismatch further shorten the operation range. Even wearable bracelet-like sensing devices have a very low range due to this reason. Thus, there are two major aspects that are going to be addressed in this Thesis: enhanced-range wearable antennas for wireless biosensors and compact "rugged-polarization" wireless sensor readers.M.S.Committee Chair: Tentzeris, Manos M.; Committee Member: DeJean, Gerald; Committee Member: Laskar, Jo

Intégration d'un géoradar ultra-portable en technologie à impression d'encre sur substrat souple

Un géoradar (GPR) effectue une détection non destructive d'objets enfouis, ou l'imagerie du sous-sol par transmission d'ondes électromagnétiques et la détection et l'analyse des réflexions. Le principal défi de GPR est la réduction de la portée de détection en raison de l'atténuation du signal grave causée par la conductivité du sous-sol qui devient plus sévère dans les hautes fréquences. Afin d'augmenter la portée de détection, GPR utilise des fréquences plus basses que les radars non-GPR et nécessite donc de plus grandes antennes qui peuvent limiter la portabilité du système. La plupart des systèmes utilisent des radars GPR à impulsion mais le FMCW (onde continue à fréquence modulée) radar peut présenter certains avantages tels que la versatilité de la fréquence, une maintenance réduite du système et une meilleure résolution de gamme. Les fréquences inférieures à 1 GHz ont d'abord été rares en radars de courte portée FMCW mais trouvent maintenant leur chemin de retour dans des systèmes comme ultra-large bande (UWB) pénétrant dans le sol des radars pour la détection des mines et ainsi que d'autres applications. Lorsque les mesures sont effectuées sur des véhicules, de grands appareils d'antenne ne sont pas un problème. La portabilité, cependant, peut devenir un problème dans les études géophysiques ou des travaux d'urgence dans laquelle on peut avoir besoin de transporter le système par des endroits accidentés, inexplorés et / ou dangereux sans accès aux véhicules. Des environnements inaccessibles peuvent nécessiter la manœuvrabilité à travers d’obstacles (montagnes, grottes, lacs, zones rocheuses). D’ailleurs, l’installation rapide du système est critique dans des conditions difficiles telles que les températures extrêmes, où le temps d'exposition est coûteux et le temps de mesure limité. Une solution pour améliorer la portabilité et la capacité de déploiement d'un système GPR est de réaliser un système complet sur un substrat qui est enroulable afin de permettre une transportation facile. L’électronique sur substrat flexible a déjà été utilisée dans des applications militaires et des sports en plein air. Actuellement, il y a quelques technologies disponibles pour réaliser l'électronique flexible qui ont été un thème majeur en recherche, chacune avec différents niveaux d'intégration. La technologie d'impression à jet d'encre offre une méthode efficace, polyvalente et rentable pour la réalisation de dispositifs flexibles. Dans ce travail, un système radar FMCW classique a été conçu et un travail présenté, pour la première fois, d’application de la technologie d'impression à jet d'encre sur un système de radar. Le système est appelé un système de radar monolithique portable dans lequel tous les agents actifs, passifs et l'antenne sont destinés à partager le même substrat enroulable continu. Ainsi, une intégration hybride est utilisée pour étudier la fiabilité et la performance du système complet enroulé autour d’un rayon serré. Plusieurs défis de conception d'un grand système ont été surmontés qui donneront un aperçu de nouveaux modèles au fur et à mesure que le niveau d'intégration à l'aide de la technologie d'impression à jet d'encre continue d’augmenter.Flexible monolithic ultra-portable ground penetrating radar using inkjet printing technology A Ground Penetrating Radar (GPR) performs nondestructive detection of buried objects, or subsurface imaging by transmitting electromagnetic waves and detecting and analyzing the reflections. The main challenge of GPR is the reduction in detection range due to the severe signal attenuation that is caused by subsurface conductivity that becomes more severe at high frequencies. In order to increase the detection range, GPR uses lower frequencies than non-GPR radars and thus requires larger antennas that may limit system portability. Most GPR systems use impulse radars however the FMCW (frequency modulated continuous wave) radar can provide some advantages such as frequency versatility, reduced system maintenance and improved range resolution. Frequencies below 1 GHz were initially uncommon in short-range FMCW radars but are now finding their way back in systems such as ultra-wideband (UWB) ground penetrating radars for mine detection and as well as other applications. When measurements are performed on vehicles, large antenna fixtures are not a problem. Portability, however, can become an issue in geophysical studies or emergency work in which one may need to transport the system through rugged, unexplored and/or hazardous locations without vehicle access and perform measurements. Inaccessible environments may require climbing up and down, squeezing through, jumping over, crawling under, maneuvering through or swimming through obstacles (mountains, caves, lakes, rocky areas). In addition to transportation, rapid system setup is critical in difficult conditions such as freezing temperatures or extreme heat where exposure time is costly and limits measurement time. One solution to enhance the portability and deployability of a GPR system for wide area rugged measurements is to realize a complete system on a continuous substrate that is rollable around a reasonably small radius and storable in a scroll or poster-like fashion for easy backpack transportation. Electronics that can flex and bend have already used in military applications and for outdoor sporting gear. Currently, there are a few types of technology available to realize flexible electronics that have been a major topic of research, each with different levels of integration. Inkjet printing technology offers a cost effective, versatile and efficient method for realizing flexible devices. In this work a classical FMCW radar system is designed and an effort is made, for the first time, to apply inkjet printing technology to a radar system. The system is referred to as a portable monolithic radar system in which all actives, passives and antenna are meant to share the same continuous rollable substrate. In doing this, a medium level of integration is used to investigate limits of system complexity, resolution and ultra miniaturization for tight rollability. Various design challenges of a large system are overcome that will hopefully give insight to new designs as the integration level using inkjet printing technology increases

Liquid RF Antennas, Electronics and Sensors: A Modeling Challenge

Abstract In this paper we present a novel approach for the modeling of multi-phase liquid RF electronics and sensors problems. The deployment of level-set based multi-phase simulation could potentially lead to the development of a new generation of computationally efficient approaches that could bridge the gap between Maxwell and solid/liquidinterface equations. Numerous examples of liquid antennas and multi-phase wireless biosensors will be presented at the conference to verify the accuracy and validity of the above approach in a variety of liquid radio-frequency wearable, implantable and printable topologies

A Conformal/Rollable Monolithic Miniaturized Ultra-Portable Ground Penetrating Radar Using Additive and Inkjet Printing

International audienceTypical UWB FMCW Ground Penetrating (GPR) Radars operate at low frequencies that require a wide sweep bandwidth thus necessitating complex architectures and bulky broad-band antennas. This poses unique challenges to the system portability especially for manual, wide-area outdoor measurements. In this paper, we present the first design, fabrication and characterization of a complete conformal and miniaturized radar system to be rolled up in a "poster-like" container using additive printing technology. As the lumped or distributed passives, the active devices and the Rx/Tx antennas may share the same flexible substrate, the proposed radar technology is considered to be monolithic. The presented proofof- concept system performs the most fundamental operations of the FMCW radar including signal generation, as well as the amplification and correlation of the LO and RF signals for GPR frequencies. Specifically, this paper outlines an ultra low cost system integration, packaging and experimental verification of a flexible/conformal monolithic radar system with almost identical performance for different degrees of flexing

A Conformal/Rollable Monolithic Miniaturized Ultra-Portable Ground Penetrating Radar Using Additive and Inkjet Printing

International audienceTypical UWB FMCW Ground Penetrating (GPR) Radars operate at low frequencies that require a wide sweep bandwidth thus necessitating complex architectures and bulky broad-band antennas. This poses unique challenges to the system portability especially for manual, wide-area outdoor measurements. In this paper, we present the first design, fabrication and characterization of a complete conformal and miniaturized radar system to be rolled up in a "poster-like" container using additive printing technology. As the lumped or distributed passives, the active devices and the Rx/Tx antennas may share the same flexible substrate, the proposed radar technology is considered to be monolithic. The presented proofof- concept system performs the most fundamental operations of the FMCW radar including signal generation, as well as the amplification and correlation of the LO and RF signals for GPR frequencies. Specifically, this paper outlines an ultra low cost system integration, packaging and experimental verification of a flexible/conformal monolithic radar system with almost identical performance for different degrees of flexing

A Dual-Band Retrodirective Reflector Array on Paper Utilizing Substrate Integrated Waveguide (SIW) and Inkjet Printing Technologies for Chipless RFID Tag and Sensor Applications

International audienceIn this paper, the dual-band retrodirective reflector array using Substrate Integrated Waveguide (SIW) and inkjetprinted technologies on paper, for operability around 3.6 GHz and 5.8 GHz is proposed. It offers the versatility of multi-band retrodirective designs potentially covering numerous RFID interrogation, sensing and communication bands

A New millimeter-wave micro-fluidic Temperature sensor for wireless passive radar interrogation

International audienceThis paper presents a micro-fluidic temperature sensor that uses a variable radar echo to measure temperature at Ka-frequency band. The device is made up of a planar gap capacitor with a micro-fluidic channel situated between the plates. As the temperature changes, the water level in the channel moves across the capacitor plates. This rising level of high permittivity liquid within the capacitor modifies the capacitance and as a result modifies the scattering parameter S11. The ensor can then be integrated with an antenna and interrogated at distance by a reader. The detected radar echo level changes in proportion to temperature when illuminated by the wave reader. Simulations were performed in order to optimize the design for the capacitor and channel, and to verify the change of S11.The micro-fluidic device was fabricated using an Su-8 micro-machining process. Measurements were performed using a VNA and a probe measurement station in order to verify the change in S11 with respect to the level of water in the micro-fluidic channel. The S11 measurements yield an 8dB range which is in agreement with the theoretical calculations that are explained in the paper. For the radar echo measurements, a 4dBm range is obtained. This corresponds to a 10° K measurable temperature range. This design allows wireless temperature sensing at a distance, thus making it an effective solution for distant temperature monitoring applications