Search

International audience; The design of a dipole antenna printed on a paper substrate is presented in this paper. The antenna which integrates a compact balun is devoted for dual-band 2.4/5 GHz WLAN applications. The antenna is based on a double-side printed multilayer paper substrate and is fed with a coaxial cable for the testing. The simulated results of the whole structure are also presented in detail and compared with the measured performances.

In this paper the experimental results of a compact low-power rectenna in paper substrate, designed to operate in the Wi-Fi band, are presented. The complete prototype, based on an annular slot antenna and a single-diode rectifier, features a weight of 1.5 grams and shows an RF-to-dc conversion efficiency in the design band of about 40 % for a -10 dBm available input power, of about 28 % at -15 dBm, and in the range [10, 22] % at -20 dBm, corresponding to an output DC voltage in the order of 320, 240 and 60 mV respectively. Additionally, the rectenna features an efficiency higher then 7 % in the whole band 1.8-2.7 dBm for a power density estimated around 3 μW/cm2.

This work presents an experimental study of second mode positive streamers propagating along mineral oilpaper interfaces. A point-plane arrangement immersed in mineral oil with the paper inclined 60 degrees to the plane electrode is used to create the liquid-solid interface. Kraft paper and a kraft fibril paper, made from cellulosic micro and nano fibrils, with higher density and lower surface roughness are used as the solid materials. High speed shadowgraphy and charge recordings are used to compare the propagation of second mode positive streamers along the mineral oil-kraft paper and mineral oil-kraft fibril paper. Streamers creeping along the mineral oil-kraft paper interface propagate mainly into the liquid, with one or two main filaments. In comparison, the streamers propagating along the kraft fibril paper show a strong reduction of the branching; these streamers consist of a single filament that propagates exactly on the solid surface. Streamers along the kraft fibril paper also have longer propagation time than for the case with kraft paper. Mutual electrostatic shielding between filaments is observed for the streamers creeping on the kraft paper. An electrostatic analysis of the influence of permittivity, density and surface roughness of the solid in the electrical properties of the streamer filaments is also performed.

This paper presents the design of a novel rectenna based on a tapered annular slot and a single-diode rectifier, optimized to operate in the Wi-Fi band and in presence of low input power (Pavs=-15 dBm). In order to obtain a compact layout a double-layer architecture has been considered, according to which the interior metal surface of the annular slot is employed as ground plane for the rectifying circuit placed on the other side of the substrate. As a result, a rectenna with an active area of only 40 × 33 mm2 and an efficiency included between 26.5 and 28% has been obtained. The antenna has been fabricated in paper substrate and tested in the anechoic chamber. Then, the rectifier has been designed and optimized within the Advanced Design System suite. Finally, the rectenna performance has been discussed and compared to the State of the Art (SoA).

Dielectric response measurements are an important maintenance and diagnostic tool for large oil filled power transformers. Regardless of if the measurements being performed in the time domain or in the frequency domain, the developed tools rely on the dielectric response being linear with excitation voltage magnitude. This paper details work done in an initial investigation into the measurement of the non-linear dielectric response in oil-paper insulated power transformers using frequency domain measurements. Measurements were performed on two transformers, with non-linear response currents measured at the higher excitation voltage levels. It was found that non-linearity in the dielectric response will result in the generation of harmonics currents particularly 3rd and 5th harmonics. There will also be effects on the fundamental current magnitude due to the higher order dielectric susceptibilities. The higher order susceptibilities will thus be evident in the measured fundamental complex admittance of the dielectric.

In this paper we study the radio frequency performance of interconnect using anisotropic conductive film (ACF). A series of experiments are conducted in order to measure and model the electrical characteristics of inkjet-printed circuits on paper substrate as well as the impedance parameters of ACF interconnect at high frequency. Four-point measurement structure, time domain reflectometry (TDR), vector network analyzer (VNA) and de-embedded technology are used to ensure the accuracy of experiments. Equivalent circuit models are built based on the experimental results. Finally, these models are considered as parts of the matching network and circuit design for the RFID receiver, which can be co-designed for developing paper-based electronic systems. It is found that since the difference between RFID tags with and without ACF interconnects is negligible, the influence of ACF interconnects can be ignored for paper-based UHF RFID tag. ACF is a feasible interconnect material for paper-based RFID tags. QC 20111129

A dual band antenna is inkjet-printed and then folded as part of a paper unmanned aerial vehicle (UAV). The patterns of the antenna are reproduced on a standard photo paper substrate using an off the shelf inkjet printer. Readily available cartridges with nanoparticle silver conductive ink are employed. A single-layer planar antenna is fed by coplanar waveguide (CPW). The geometry of the radiating element consists of a semicircle with a centered square slot. In order to examine the effect of bending on performance, the antenna is tested unfolded and then folded when integrated onto the airplane. Two configurations of the folded antenna on the plane are analyzed. The aim is to investigate the feasibility of fabricating foldable antennas for paper airplanes using low-cost inkjet printing techniques. The antenna operates at the existing 2.4 GHz and 5.2 GHz WLAN bands. Finite different time domain simulations compare well with measurement.

In this paper, we proposed the development and implementation of novel paper-based UHF RFID designs for anti-counterfeiting and security. Miniaturization and global-band antenna configurations and utilization of inkjet printing techniques in/on organic substrates, such as paper, that will enable the low cost and large-scale implementation of RFID-enabled semi-autonomous sensors for "cognitive-intelligence" applications, are also discussed for a variety of security-related areas, featuring a great potential for low-cost large-scale solutions.

In this paper, an overview of novel integration approaches for improved performance UHF radio frequency identification (RFID) tags and embedded sensors and batteries is presented. Organic substrates, such as paper, that have been very rarely used in UHF and RF applications in the past and could potentially utilize inkjet printing techniques, are also thoroughly investigated for the realization of ultra- low-cost RFID/Sensor tags for frequencies ranging from 13.56 MHz up to 950 MHz for the first time ever. The proposed technology could potentially revolutionize wearable and conformal wireless sensor networks (WSN).

This paper documents the successful development and evaluation of a novel membrane switch. The process results in lower environmental burdens and manufacturing costs than current screen-printed polyester solutions. Detailed is the evaluation of offset lithographically printed conductive tracks on paper substrates for application in computer keyboard assemblies. Offset lithographic printing of conductive tracks is an emerging fabrication technique finding application in low-cost, high volume, flexible circuitry applications. Several fully featured demonstration keyboards and switch membranes have been constructed and tested. These are currently in use in office environments and are presented.

Dielectric response measurements are an important maintenance and diagnostic tool for large oil filled power transformers. There are numerous operational disadvantages to performing dielectric response measurements offline, such as the need to disconnect the transformer from the grid, the time taken for the tests and the risk posed to the network. There is therefore a need to develop techniques to perform dielectric response measurements online. This paper presents the results from experimental work conducted in developing a method for performing Frequency Domain Spectroscopy (FDS) measurements on an energized three phase transformer in the laboratory. A chirp excitation voltage signal is used in this work to reduce the measurement time. Extraction of the magnitude and phase information, from the chirp signal, is accomplished using a chirp-matched fitter. Signal injection onto and out of the transformer under test is achieved via neutral connections or “virtual” neutral connections in the set-up. The experimental work establishes the feasibility of using the FDS test on an energized transformer.

Resin impregnated paper (RIP) is a relatively new insulation system recommended for the use in transformer bushings. In the recent past, RIP has acquired prominence as insulation in bushings, over conventional oil impregnated paper (OIP), in view of its overwhelming advantages the more important among them being low dielectric loss and possibility for positioning the bushing at any desired angle over the transformer. In addition, the fact that such systems do not pose problems of fire hazard is counted as a very important consideration. The disadvantage of RIP compared to OIP, however, is its much higher cost and involved manufacturing process. The temperature rise in RIP bushings under normal operating conditions is seen to be a difficult parameter to control in view of the limited options for effective cooling. It is therefore essential to take serious note of this aspect, to arrest rapid deterioration of bushing. The degradation of dry- type insulation such as RIP is often due to thermal stress. The long time performance thereof, depends strongly, on the maximum operating temperature. With this in view, the Authors have developed a theoretical model and computational method to study the temperature distribution in the body of insulation. The Authors consider that the basis for the model as being the temperature and electric stress aided AC conductivity. The ensuing heat balance (continuity) equations in 2-D cylindrical geometry are treated as a Dirichelet-Neumann boundary value problem.

Electrical failure of insulation is known to be an extremal random process wherein nominally identical pro-rated specimens of equipment insulation, at constant stress fail at inordinately different times even under laboratory test conditions. In order to be able to estimate the life of power equipment, it is necessary to run long duration ageing experiments under accelerated stresses, to acquire and analyze insulation specific failure data. In the present work, Resin Impregnated Paper (RIP) a relatively new insulation system of choice used in transformer bushings, is taken as an example. The failure data has been processed using proven statistical methods, both graphical and analytical. The physical model governing insulation failure at constant accelerated stress has been assumed to be based on temperature dependent inverse power law model.

In this paper, the feasibility of inkjet printing process for the development of a ldquoSystem-on-Paperrdquo RF system was demonstrated for the first time. The process of designing a wireless transmitting sensor module entirely on paper was outlined and its performance was measured. The measured sensor results show good agreement with the manufacturerpsilas specs. The relatively higher heat insulation of paper and silver ink to temperature changes compared to other conductors and packaging materials makes it an ideal substrate for housing sensors, as well as numerous ldquogreenrdquo RF modules.

Radio frequency identification (RFID) can be utilized for the tagging of a wide variety of application. A planar inverted F antenna (PIFA) for real time locating has been designed, built and characterized on paper substrate. In specific the PIFA for tagging of metallic objects such as containers in ports or automotive applications is designed, fabricated, and characterized on a paper substrate. The antenna interconnect, or simply the shorting via A via, was drilled though the paper substrate using laser in one of the corners of the structure and, and is characterized by plotting S parameters. Agreement between simulation and measurements provide the proof of concept that paper is a good candidate for a multilayer low cost substrate. This effort proves for the first time, the feasibility of building 3D structure on paper with z-interconnects.

In this paper, inkjet-printed RFID-enabled sensor modules are investigated for the first time on paper-based substrates for UHF sensing/monitoring applications. An inkjet-printed antenna using silver nano particles on paper substrate is presented and utilized for the compact implementation of the wireless part of the node. The efficiency of the modulation scheme of the sensor signal is characterized at the UHF RFID Band operating around the center frequency of 433.9 MHz, verifying the feasibility of the sensor/rfid integration. Such low-cost integrated sensing nodes would enable the deployment of large ad-hoc wireless sensor networks that would mark a revolution in wireless automatic identification and real-time monitoring for medical, inventory and security applications.

Paper is one of the best substrate candidates for radio frequency identification (RFID) and ubiquitous sensing applications due to the fact that it is not only one of the lowest cost materials, but is environmentally friendly and can be easily used for mass reel-to-reel processing. In this paper, the UHF/RF electrical characterization of the paper substrate, using the microstrip ring resonator method, has been performed yielding an accurate low-value range for the dielectric constant (epsivr) and loss tangent (tandelta). A UHF RFID antenna is designed and inkjet printed on paper to demonstrate the applicability of this material. The presented approach could potentially set the foundation for very large ultra-low-cost ad-hoc networks for cognitive radio and sensing applications.

We discussed partial discharge (PD) inception characteristics of liquid nitrogen (LN/sub 2/)/polypropylene (PP) laminated paper composite insulation system for high temperature superconducting (HTS) cables. In this paper, we measured PD inception characteristics under lightning impulse voltage application by both electrical and optical methods. The impulse PD inception characteristics were compared with those under ac voltage application, and the PD generation mechanisms were discussed. Experimental results revealed that PD detection sensitivity under lightning impulse voltage application reached as small as 6 pC. PD was verified to be generated not only inside the butt gap but also outside the butt gap under both lightning impulse and ac voltage applications. AE sensors could also be applied to PD measurement under ac voltage application.

Paper insulated lead covered (PILC) cables provide the backbone of underground power distribution in the United States and other parts of the world. Efficient replacement of aged PILC is a looming challenge for the utility industry. Interdigital dielectrometry sensors that measure the dielectric properties of PILC cable are presented. Such sensors may be used to perform low cost health assessment of excavated cable samples. An overview of the theoretical groundwork is presented along with steady state and transient experimental results.

This paper reviews silicon implementations of threshold logic gates, covering several decades. It details numerous VLSI implementations including: capacitive (switched capacitor and floating gate with their variations), conductance/current (pseudo-nMOS, output-wired-inverters, and a plethora of solutions evolved from them), as well as many differential solutions. Nanoelectronic implementations (e.g., based on negative resistance devices and on single electron technologies) are shortly mentioned

HVDC cables play an important role in a growing number of HVDC links. For almost all of these cables, mass impregnated paper is used as electrical insulation. The electrical conductivity of this insulation is given by a commonly used empirical formula. This formula takes into account the temperature and stress dependency of the conductivity. This paper derives a physics-based equation describing ionic conduction. In good approximation this theoretical formula gives the same results as the empirical one. This makes it most likely that the conduction in paper mass impregnated cables is of the ionic kind. The derived formula uses some physical parameters like the inter-potential well distance, the potential well depth and the carrier concentration. Numerical values of these quantities for mass impregnated paper are given. According to the proposed model, the stress dependency results from the inter-potential well distance only. The temperature dependency results merely from the depth of the potential energy wells. In addition some possible underlying physical processes are described. >