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En l'actualitat vivim en un entorn amb tendència a la connectivitat entre tot el que ens envolta. Això comporta l'ús massiu de dispositius electrònics de radiofreqüència, que necessiten de nous mètodes de fabricació i materials per poder reduir l'impacte mediambiental que suposarà aquest escenari. En aquest context, el present Treball de Final de Grau té l'objectiu principal d'estudiar la possibilitat d'us del paper com a substrat per a la fabricació de circuits de microones. Per poder realitzar aquest estudi, en primer lloc es descriu l'actualitat en la investigació de tecnologies desenvolupades sobre aquest substrat. El posterior repàs en els paràmetres utilitzats al llarg de la memòria té la finalitat de començar la lectura de l'estudi redactat amb un millor coneixement de les magnituds i conceptes involucrats. La metodologia es basa en el càlcul inicial de les diferents variables de cada un dels dispositius tractats . Aquests resultats son contrastats amb l'assistent de simulació, i posteriorment es confecciona el disseny del circuit. Amb la simulació electromagnètica, la qual és la mesura de major precisió atès son aplicades les equacions de Maxwell en el circuit; es realitza un exercici de discussió sobre el resultat obtingut, de manera que s'estudia la viabilitat del circuit en el seu disseny en substrat de paper. La memòria conclou amb una reflexió general sobre diferents aspectes del treball realitzat, així com diferents línies de treball futur. Nowadays we live in an environment with a tendency to connect between everything that surrounds us. This entails the massive use of radio frequency electronic devices, which need new manufacturing methods and materials for reducing the environmental impact due to this reality. In this context, the present Final Degree Project has the main objective of studying the possibility of using paper as a substrate in the microwave circuits. First of all, the study explains the current situation in the research of technologies developed on the described substrate. Secondly, it's necessary a review of the parameters used throughout the memory has the purpose of beginning the reading of the study written with a better knowledge of the magnitudes and concepts involved. The methodology is based on the initial calculation of the different variables of each one of the treated devices. These results are contrasted with the simulation assistant and also with the circuit schema. The simulation concludes with electromagnetic test, which is the measure of greater precision, due to be applied the Maxwell equations in the circuit. Then, with all results obtained, it starts the study of viability. The report concludes with a general reflection on different aspects of the work done, as well as different lines of future work. En la actualidad vivimos en un entorno con tendencia a la conectividad entre todo lo que nos rodea. Esto conlleva el uso masivo de dispositivos electrónicos de radiofrecuencia, que necesitan de nuevos métodos de fabricación y materiales para poder reducir el impacto medioambiental que supondrá este escenario. En este contexto, el presente Trabajo de Fin de Grado tiene el objetivo principal de estudiar la posibilidad de uso del papel como sustrato para la fabricación de circuitos de microondas. Para poder realizar este estudio, en primer lugar se describe la actualidad en la investigación de tecnologías desarrolladas sobre este sustrato. El posterior repaso en los parámetros utilizados a lo largo de la memoria tiene el fin de comenzar la lectura del estudio redactado con un mejor conocimiento de las magnitudes y conceptos involucrados. La metodología se basa en el cálculo inicial de las diferentes variables de cada uno de los dispositivos tratados. Estos resultados son contrastados con el asistente de simulación, y posteriormente se confecciona el diseño del circuito. Con la simulación electromagnética, la cual es la medida de mayor precisión dado son aplicadas las ecuaciones de Maxwell en el circuito; se realiza un ejercicio de discusión sobre el resultado obtenido, por lo que se estudia la viabilidad del circuito en su diseño en sustrato de papel. La memoria concluye con una reflexión general sobre diferentes aspectos del trabajo realizado, así como diferentes líneas de trabajo futuro.

This paper presents a wireless, self-powered, affinity-based biosensor based on the integration of paper-based microfluidics with our previously reported method for self-assembling radio-frequency (RF) antennas. At the core of the proposed approach is a silver-enhancement technique that grows portions of a RF antenna in regions where target antigens hybridize with target specific affinity probes. The hybridization regions are defined by a network of nitrocellulose based microfluidic channels which implement a self-powered approach to sample the reagent and control its flow and mixing. The integration substrate for the biosensor has been constructed using polyethylene and the patterning of the antenna on the substrate has been achieved using a low-cost ink-jet printing technique. The substrate has been integrated with passive radio-frequency identification (RFID) tags to demonstrate that the resulting sensor-tag can be used for continuous monitoring in a food supply-chain where direct measurement of analytes is typically considered to be impractical. We validate the proof-of-concept operation of the proposed sensor-tag using IgG as a model analyte and using a 915 MHz Ultra-high-frequency (UHF) RFID tagging technology.

The newly developed research area of inkjet-printed radio frequency (RF) electronics on cellulose-based and synthetic paper substrates is introduced in this paper. This review paper presents the electrical properties of the paper substrates, the printed silver nanoparticle-based thin films, the dielectric layers, and the catalyst-based metallization process. Numerous inkjet-printed microwave passive/ative systems on paper, such as a printed radio frequency identification (RFID) tag, an RFID-enabled sensor utilizing carbon nanotubes (CNTs), a substrate-integrated waveguide (SIW), fully printed vias, an autonomous solar-powered beacon oscillator (active antenna), and artificial magnetic conductors (AMC), are discussed. The reported technology could potentially act as the foundation for true “green” low-cost scalable wireless topologies for autonomous Internet-of-Things (IoT), bio-monitoring, and “smart skin” applications.

session: Antenna and Propagation; International audience; The design of antennas on cellulosic flexible materials such as paper can be very challenging because of the limited thickness and the high losses in the Radio Frequency (RF) domain. In this paper, a novel patch antenna with an origami structure is proposed to address the null radiation efficiency obtained with the conventional paper-based structure. As the electromagnetic waves mostly travel in the air, ideal conditions such as no loss and a low dielectric constant allow for the asymptotic value of directivity of microstrip antennas to be reached with a 63 % experimental radiation efficiency. This flexible antenna can be used for RF energy harvesting or sensing applications due to the sensitivity of paper on atmospheric conditions.

Noise optimization for FET low noise amplifiers (LNAs) are demonstrated through insights gained from analytical formulations derived using noise transformation matrix. The invited paper reviews the status of analytical noise optimization of FET LNAs including single-/dual-band FET LNAs with the lossless/lossy input match networks and broadband FET LNAs with the lossless input networks.

The traditional space telemetry, tracking, command and communication system works in the radio frequency band. With the improvement on measurement accuracy and communication capacity in space missions, the traditional means have a certain bottleneck in dealing with the development of future space missions. The inherent lightweight, high parallel, high capacity and fine processing capabilities of Optics and microwave photonics show the potential to solve the above problems. This paper summarizes the innovative work of the Southwest China Institute of Electronic Technology in the application of laser measurement and communication integration, microwave photonic RF front-end technology in space telemetry, tracking, command and communication system. The experimental platform is established for verification, the accuracy of ranging and velocity measurement reaches millimeter level at 10Gbps single channel transmission rate with 1E-9 bit error rate under a simulation satellite-ground link. The microwave photonic RF front-end can be compatible with S to Ka band, with a sampling rate of 20Gsps and a signal bandwidth of 5GHz. It is expected to be applied to next generation of space telemetry, tracking, command and communication system or navigation and relay system.

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.

The numerous features of the reconfigurable antenna are discussed in this paper from the basic idea which will give us the broader perception into the fundamental design approach to the advance methodology. These are the modern technological antennas which are capable of analyzing the surrounding and perform necessary adjustment in order to attain and maintain maximum performance and these adjustments are performed by applying different technologies such as varactors, microelectromechanical systems (based on radio frequency), PIN diodes, and photoconductive plates. This kind of antenna is also capable of avoiding noise sources and capable of improvising to gain of the system and security due to their special properties, they consume less power and saves the energy by directing signals only toward the intended direction. Due to this phenomenal property of self-adjustment of with respect to the environments condition, reconfigurable antenna gets a wide-open field of operation in cognitive radios, satellite communications, multi-input multi-output systems (MIMO), and other various fields.

A new paper-based microfluidic switch activated by surface acoustic wave (SAW) was presented. The switch was comprised of two folded paper microchannels and an unfolded paper microchannel. One of the folded paper microchannels was connected with the unfolded paper microchannel. Two interdigital transducers (IDTs) and two reflectors were fabricated on 128° yx-LiNbO3 substrate using microelectrical technology. When an amplified RF signal was applied to the IDTs, a droplet on the piezoelectric substrate was actuated to the unfolded paper microchannel by SAW. Folded angle of a folded paper microchannel was increased and connected with the other folded paper microchannel to implement ‘on’ function of the microfluidic switch. The switch was examined using red dye solution microfluids and mixed indicating solution of 330 mmol/L Citric acidmonohydrate, 10 mmol/L N-(1-Naphthyl) ethylenediamine dihydrochloride and 50 mmol/L Sulfanilamide. The presented switch is valuable for programmable paper-based microfluidic de...

The radio frequency (RF) argon plasma induced surface modification of paper revealed novel surface characteristics and substantially changed surface topography. It was found that RF-argon glow discharge affects surface properties resulting in photo-degradation and chain-scission mechanism on paper network structure. High-power and extended treatment time caused increasing elemental carbon, while decreasing the oxygen concentration on paper surface. However, increased hydroxyls and the creation of new carbonyl functionalities were verified by trifluoroacetoanhydride and pentafluorophenylhydrazine in vapor-phase derivatization reactions.

A full-band direct-conversion receiver using a microwave photonic in-phase and quadrature (I/Q) mixer is proposed and experimentally evaluated in terms of radio frequency (RF) range, port isolation, phase imbalance, conversion gain, noise figure, spurious-free dynamic range, and error vector magnitude. The proposed microwave photonic I/Q mixer shows significant advantages in local oscillator leakage and I/Q phase imbalance over entire RF bands, which are recognized as major drawbacks of conventional direct-conversion receivers.

Compressive sampling (CS) has attracted considerable attention in microwave and radio frequency (RF) fields in recent years. It enables the acquisition of high-frequency signals at a rate much smaller than their Nyquist rates. Combined with photonics technology, traditional CS systems can significantly enlarge their operating bandwidth, which offers great potential for spectrum sensing in cognitive radios. In this Letter, we review our recent work on photonic CS systems for wideband spectrum sensing. First, a proof-of-concept photonics-assisted CS system is demonstrated; it is capable of acquiring numerous radar pulses in an instantaneous bandwidth spanning from 500 MHz to 5 GHz with a 500-MHz analog-to-digital converter (ADC). To further reduce the acquisition bandwidth, multi-channel photonics-assisted CS systems are proposed for the first time, enabling the acquisition of multi-tone signals with frequencies up to 5 GHz by using 120-MHz ADCs. In addition, the system bandwidth is increased from 5 to 20 GHz by employing time-interleaved optical sampling.

Considering its different interaction forms with cellulose, water is very problematic as we consider high frequencies electromagnetic applications of papers. Thereby, cellulosic materials exhibit high losses in the radiofrequency (RF) domain. In this paper, the RF dielectric behavior of different papers versus their moisture content is described and the huge impact of water upon losses is shown. We also present a three components effective medium theory that is able to describe and predict the impact of this water content.

This study designed and fabricated a frequency-selective structure-based security paper for the electromagnetic detection system of a security gate, which aims to prevent leakage of confidential documents. When a functional paper embedded with a frequency-selective pattern that selectively reflects a specific frequency is being leaked out of a security zone, the electromagnetic detection system receives and detects the intensity of the electromagnetic wave reflected from the security paper passing through an antenna gate, which transmits/receives RF signals. A stable detection performance of the security paper can be ensured by improving the incidence angle stability for incident waves and reducing the reflection loss. This study designed a frequency-selective structure with stable frequency reflection properties at the X-band by utilizing a Jerusalem cross structure. The proposed design was realized using the screen printing technique, which could implement a circuit, to print silver ink on a plain paper. To verify the applicability of the frequency-selective structure-based security paper, an RF detection system with a multiple antenna array was constructed and the intensity of the received signals was measured. The measurement was performed for various scenarios, and the result showed that the proposed security paper was well detected.

This article reports the first results of a Nafion&reg, based, solid state, non-volatile, electronically reconfigurable Radio Frequency (RF)-switch integrated to a co-planar waveguide transmission line (CPW) in shunt mode, on a flexible paper substrate. The switch is based on a metal&ndash, insulator&ndash, metal structure formed respectively using Silver&ndash, Nafion&ndash, aluminum switching layers. The presented device is fully passive and shows good performance till 3 GHz, with an insertion loss less than 3 dB in the RF-on state and isolation greater than 15 dB in the RF-off state. Low-power direct current pulses in the range 10 V/0.5 mA and &minus, 20 V/0.15 A are used to operate the switch. The device was fabricated in an ambient laboratory condition, without the use of any clean room facilities. A brief discussion of the results and potential application of this concept in a re-configurable chipless RFID tag is also given in this article. This study is a proof of concept of fabrication of electronically re-configurable and disposable RF-electronic switches on low cost and flexible substrates, using a process feasible for mass production.

Se adopta la topología retro-directiva Van-Atta para el diseño de un tag RFID, que luego se implementará en un sustrato de papel flexible y de bajo coste. En el PFC presentat, ens enfoquem en la implementació de topologies de tags RFID amb l'ús d'un substrat de paper per obtenir dispositius fàcils de fabricar, flexibles i de baix cost. La primera estructura consisteix en una configuració de dipol amb un anell inductiu que garanteix l'adaptació d'impedància desitjada entre els ressonadors i el xip RFID; després, proposem un arranjament de dos dipols en una configuració retro-directiva. Els dos dissenys van ser avaluats mitjançant el mesurament de la potència rebuda pel lector situat a uns 90 cm de distància, per a diferents angles de senyal incident. La solució de dos elements va mostrar una millora de 8dB en la secció creuada del radar bistatico (Bistatic radar cross section). I menys degradació en el nivell de senyal quan el senyal d'incidència es mou de la direcció ortogonal. En el PFC presentado, nos enfocamos en la implementación de topologías de tags RFID con el uso de un sustrato de papel para obtener dispositivos fáciles de fabricar, flexibles y de bajo coste. La primera estructura consiste en una configuración de dipolo con un anillo inductivo que garantiza la adaptación de impedancia deseada entre los resonadores y el chip RFID; luego, proponemos un array de dos dipolos en una configuración retro-directiva. Los dos diseños fueron evaluados mediante la medición de la potencia recibida por el lector ubicado a unos 90cm de distancia, para distintos ángulos de señal incidente. La solución de dos elementos mostró una mejora de 8dB en el RCS biestatico (Bistatic radar cross section). Y menos degradación en el nivel de señal cuando la señal de incidencia se mueve de la dirección ortogonal. In this PFC, RFID tag topologies implemented in paper are presented; the use of a paper substrate permits to obtain low-cost, flexible and easy-to-fabricate devices. The first structure consists in a dipole with an inductive loop that guarantees the desired impedance matching between the resonators and the RFID chip; then, an array of two dipoles in a retro-directive configuration is proposed. The two designs were evaluated by measuring the power received by a reader placed at 90 cm distance, for different incidence angles of the signal; the two-element approach showed an 8 dB improvement in the bistatic radar cross section, and less degradation of the signal level as the incidence moves from the orthogonal direction.

For the first time, high quality factor (Q), meander inductors are demonstrated utilizing inkjet-printing on organic paper substrates. Quality factors of up to 25, which is an order of magnitude greater than previous works, and inductance values of up to 8 nH are achieved. The high self-resonance frequency (SRF) of 8 GHz makes it possible for the inductors to be used in the 900 MHz and 2.4 GHz RFID bands, and in 5 GHz Wifi band. Furthermore, a study into the performance and miniaturization effects of inkjet-printing ferromagnetic nanomaterial onto the inductors shows increases in inductance of up to 5%. Applications for inkjet printed inductors include all-printed flexible and wearable filters, resonators, and microwave matching networks.

In this paper, we study the waveform design problem for a single-input single-output (SISO) radio-frequency (RF) wireless power transfer (WPT) system in frequency-selective channels. First, based on the actual non-linear current-voltage model of the diode at the energy receiver, we derive a semi-closed-form expression for the deliverable DC voltage in terms of the incident RF signal and hence obtain the average harvested power. Next, by adopting a multisine waveform structure for the transmit signal of the energy transmitter, we jointly design the multisine signal amplitudes and phases over all frequency tones according to the channel state information (CSI) to maximize the deliverable DC voltage or harvested power. Although our formulated problem is non-convex and difficult to solve, we propose two suboptimal solutions to it, based on the frequency-domain maximal ratio transmission (MRT) principle and the sequential convex optimization (SCP) technique, respectively. Using various simulations, the performance gain of our solutions over the existing waveform designs is shown.

We present an overview of the historical development and current state-of-the-art in measurement techniques for radio frequency (RF) nanotechnology. The field of RF nanotechnology focuses on the study and engineering of RF and microwave devices that are enabled by nanomaterials and other advances in nanoscience. Measurements play a critical role in this emerging field, enabling the transition from discoveries of new phenomena and new materials to practical engineering and eventual commercial application of RF nanotechnology. One critical challenge is to overcome the inherent impedance mismatch between nanoscale systems and commercial test equipment. Early work focused on the extension of existing guided-wave and on-wafer microwave measurement techniques to nanoelectronic devices. The objective of most of these early techniques was measurement of the complex, two-port scattering parameters of passive devices that incorporated a small number of individual nanoscale building blocks. More recently, local measurement techniques such as near-field scanning microwave microscopy have been developed for broadband characterization of nanomaterials and intradevice measurement of defects, contacts, and interfaces.

For the first time, we demonstrate the feasibility of realizing ultra-wideband antennas through ink-jetting of conductive inks on commercially available paper sheets (paper as an RF substrate). The characterization of the conductive ink as well as of the electrical properties of the paper substrate is reported for frequencies up to 10GHz. This work is one step further towards the development of low-cost environmentfriendly conformal printed antennas/electronics for ad-hoc wireless sensor networks operating in rugged environments.

In this paper, a review of the authors' work on inkjet-printed flexible antennas, fabricated on paper substrates, is given. This is presented as a system-level solution for ultra-low-cost mass production of UHF radio-frequency identification (RFID) tags and wireless sensor nodes (WSN), in an approach that could be easily extended to other microwave and wireless applications. First, we discuss the benefits of using paper as a substrate for high-frequency applications, reporting its very good electrical/dielectric performance up to at least 1 GHz. The RF characteristics of the paper-based substrate are studied by using a microstrip-ring resonator, in order to characterize the dielectric properties (dielectric constant and loss tangent). We then give details about the inkjet-printing technology, including the characterization of the conductive ink, which consists of nano-silver particles. We highlight the importance of this technology as a fast and simple fabrication technique, especially on flexible organic (e.g., LCP) or paper-based substrates. A compact inkjet-printed UHF ldquopassive RFIDrdquo antenna, using the classic T-match approach and designed to match the IC's complex impedance, is presented as a demonstration prototype for this technology. In addition, we briefly touch upon the state-of-the-art area of fully-integrated wireless sensor modules on paper. We show the first-ever two-dimensional sensor integration with an RFID tag module on paper, as well as the possibility of a three-dimensional multilayer paper-based RF/microwave structure.

Distributed small-scale electronics for IoT applications are on the rise. Power delivery for such electronics requires innovative design techniques to improve energy efficiency. This paper summarizes energy delivery challenges for IoT devices and discusses several design techniques for efficient power delivery units. Such design solutions cover challenges like energy harvesting from very low input voltage, maximized energy harvesting, energy delivery with multiple voltage domains and design using low voltage devices to sustain higher than breakdown voltages.

The letter presents the design, fabrication, and measurement of a configurable radio frequency identification (RFID) tag based on time-domain reflections. The tag circuit contains a microstrip line (ML) that propagates radio frequency (RF) signals, and a group of capacitors that introduce impedance discontinuities to encode binary codes. The configurability of the tag circuit is allowed by connecting the nearby-placed capacitors with the ML. Ink-jet printing technology is employed to implement the layout of the proposed tag on paper substrate. To overcome the limitations of printed metallic tracks, a linearly tapering technique is proposed. With this technique, a four-bit configurable passive chipless RFID tag is realized. Both time-domain reflectometry (TDR) measurements and ultrawideband (UWB) characterizations were conducted for the proposed tag, and the results are in good consistence with the simulation ones from the circuit simulator advanced design system (ADS). Owing to its low cost fabrication and environmentally friendly nature, the proposed tag has great potential to be widely employed in low-end RFID applications. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53: 2781-2786, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26412