Qiang Chen

Qiang Chen
KTH Royal Institute of Technology | KTH

About

108
Publications
27,292
Reads
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2,676
Citations
Citations since 2016
5 Research Items
2012 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300

Publications

Publications (108)
Article
This study addresses the difficulty of obtaining high crystalline quality non-polar a-plane AlN films grown epitaxially on r-plane sapphire substrates by applying a high-temperature annealing process to films grown via standard-temperature metal organic chemical vapor deposition. Atomic force microscopy results demonstrate the occurrence of a signi...
Conference Paper
A compressed sensing (CS) based impulse radio ultra-wideband (IR-UWB) receiver with two-path noise-reducing RF front-end architecture is proposed. By adding an identical input path (antenna and gain stage) together with a mixer, the noise in the received signal before feeding into the CS sampling block is alleviated comparing with the conventional...
Article
This paper presents a multi-frequency time division multiple access (MF-TDMA) protocol for Radio Frequency IDentification (RFID) monitoring system in industrial Internet of Things (IoT). Unlike critical industrial control system which requires 1-2 ms response in communication, the monitoring system in industries normally demands a guaranteed delay...
Article
This paper presents a 2.4-GHz radio frequency (RF) and ultra-wide bandwidth (UWB) hybrid real-time locating system (RTLS) for industrial enterprise Internet of Things (IoT). It employs asymmetric wireless link, that is, UWB radio is utilised for accurate positioning up to 10 cm in critical sites, whereas 2.4-GHz RF is used for tag control and coars...
Conference Paper
This paper addresses the issue of UWB signal acquisition in the context of wireless powered UWB RFID systems. In this scenario, the data transmission is based on short packet so as to meet the micro-power budget of autonomous power harvesting. The burst short packet transmission as well as the low duty cycling UWB pulse modulation places a stringen...
Conference Paper
This paper presents a Multi-Frequency Time Division Multiple Access (MF-TDMA) scheme for long-packet and energy-constraint Radio Frequency Identification (RFID) sensing applications. The scheme takes advantages of both multiple transmission channels and scheduled time slots for high throughput and low latency. In addition, a dedicated channel is al...
Article
Low temperature and the fragility features of paper substrate require novel approach for the heterogeneous integration of silicon chip and printed components. In this paper, RF interconnection via capacitive coupling is proposed for printed paper electronics. Capacitive coupling combined with the printed transmission line is used as the signal chan...
Article
This paper presents a fully-printed chipless radio frequency identification sensor tag for short-range item identification and humidity monitoring applications. The tag consists of two planar inductor–capacitor resonators operating wirelessly through inductive coupling. One resonator is used to encode ID data based on frequency spectrum signature,...
Article
Full-text available
This paper presents comparative environment impact evaluation and assessment between inkjet printing technology based Electrocardiography (ECG) Bio-patch and traditional Printed Circuit Board (PCB) based ECG Holters. Due to the complexity of electronic systems and the consistent lack of solid data about a product’s life cycles, a limited comparison...
Article
Full-text available
In-home healthcare services based on the Internet-of-Things (IoT) have great business potential; however, a comprehensive platform is still missing. In this paper, an intelligent home-based platform, the iHome Health-IoT, is proposed and implemented. In particular, the platform involves 1) an open-platform-based intelligent medicine box (iMedBox) w...
Article
Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on...
Article
Full-text available
Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on...
Article
Radio-frequency identification (RFID) with a received signal strength indicator (RSSI) is a low-cost and low-complexity approach for item-level indoor localization. Although RSSI-based algorithms suffer from multipath effect and other environmental factors, reference tags and RSSI changes can be utilized to further improve the localization accuracy...
Article
A combined analytical and numerical process has been developed to model and optimize thermoelements. In this way, the performance of commercial n- and p-type thermoelectric materials can be optimized to deliver the maximum output power and conversion efficiency. The validity of the method is demonstrated using a silicon germanium unicouple.
Conference Paper
The medication noncompliance problem has caused serious threat to public health as well as huge financial waste would wide. The emerging pervasive healthcare enabled by the Internet-of-Things offers promising solutions. In addition, an in-home healthcare station (IHHS) is needed to meet the rapidly increasing demands for daily monitoring and on-sit...
Conference Paper
Printing is considered a cost-effective way to fabricate electronics on unconventional substrates enabling, for example, smart packaging. Functionalized multi-walled carbon nanotubes (f-MWCNTs) having carboxylic groups on their surfaces possess great potential as flexible resistive humidity sensor. In this paper, we report on the inkjet printing an...
Article
Radio frequency identification (RFID) is a compelling technology for Internet of Things (IoT). Ultra-wideband (UWB) technology is one promising wireless technique for future RFID, especially for high-throughput sensing applications. On-off keying UWB RFID system provides high pulse rate but suffers severe collisions that limit the system throughput...
Article
The integration of sensors endows the packages with intelligence and interactivity. This paper is considered the most suitable substrate of smart packages because it is cost-effective, light, flexible, and recyclable. However, common concern exists regarding the reliability of paper-based system against bending and folding. In this paper, inkjet-pr...
Article
Full-text available
This paper reviews recent advances in fully printed chipless radio frequency identification (RFID) technology with special concern on the discussion of coding theories, ID generating circuits, and tag antennas. Two types of chipless tags, one based on time-domain reflections and the other based on frequency domain signatures, are introduced. To ena...
Conference Paper
Full-text available
Driven by the increased interest in wearable long-term healthcare monitoring systems, varieties of dry electrodes are proposed based on different materials with different patterns and structures. Most of the studies reported in the literature focus on proposing new electrodes and comparing its performance with commercial electrodes. Few papers are...
Article
In-home health care services based on the Internet-of-Things are promising to resolve the challenges caused by the ageing of population. But the existing research is rather scattered and shows lack of interoperability. In this article, a business-technology co-design methodology is proposed for cross-boundary integration of in-home health care devi...
Article
Full-text available
This article demonstrates in-depth electromagnetic analysis of a radio frequency identification tag antenna manufactured by inkjet printing technology on different paper substrates to achieve ultra-low cost flexible radio frequency identification tags using a novel hole-matching technique for reducing the consumption of substrate material, and cond...
Article
Full-text available
We demonstrate for the first time an RFID tag antenna which itself is humidity sensor and also provides calibration functionality. The antenna is comprised of T-matching network and horizontally meandered lines for impedance matching and reliable near-field communication. The novel contour design provides humidity sensing, and calibration functions...
Article
Full-text available
This letter presents the design, simulation, fabrication, and characterization of an $LC$-resonator-based chipless RFID tag. The ID-generating circuit is designed based on a reconfigurable $LC$ resonance circuit. Phase position modulation (PPM) coding is used for the enhancement of the coding capacity. The tag has been realized on packaging paper u...
Conference Paper
In-home healthcare services based on the Internet-of-Things (IoT) have big potential in business. To exploit this opportunity, an ecosystem should be established first. Technical solutions should aim for a cooperative ecosystem by addressing the interoperability, security, and system integration. In this paper, we propose an ecosystem-driven design...
Conference Paper
Full-text available
A healthcare solution for medication noncompliance problem would help to save $177 billion annually in the United States. In addition, an in-home healthcare station (IHHS) is needed to meet the rapidly increasing demands for daily monitoring with on-site diagnosis and prognosis. In this paper, an intelligent medication management system is proposed...
Conference Paper
Full-text available
An RFID antenna with integrated humidity sensor and calibration functionality for wireless sensor network is proposed. The antenna is composed of series and shunt stubs for impedance matching and reliability for near-field communication. The innovative ladder contour structure plays the key role for humidity sensing, and sensor calibration. The qua...
Conference Paper
Full-text available
The purpose of this paper is two-fold. Firstly, we have attempted to design a planar Sierpinski fractal antenna with stacked configuration for multiband applications. The stacked configuration of Sierpinski fractal patch and Sierpinski grid are employed to improve the multiband characteristics. The operating frequencies obtained are at 3.3 GHz, 5GH...
Article
Full-text available
In this paper, we demonstrate for the first time an RFID tag antenna manufactured by advanced inkjet printing technology on paper substrate using novel hole-matching technique for reducing the consumption of substrate material and conductive ink while attaining green RFID tags. In-depth electromagnetic analysis is performed methodologically for opt...
Article
Full-text available
For the first time, two-arm planar sinuous antenna is demonstrated to realize the emerging concept of integrating RFID functionalities along with sensors and other wireless applications for “green” electronics. In-depth, parametric analysis is performed for the proposed antenna which is fabricated on a paper substrate using revolutionary inkjet pri...
Conference Paper
Full-text available
This paper reviews recent research on Ultra-Wideband (UWB) techniques for the next generation Radio Frequency IDentification (RFID) towards the Internet-of-Things (IoT), conducted by Vinn iPack Center at KTH, Sweden. First, we introduce an inkjet printed chipless UWB RFID for ultra-low cost applications such as item-level tracking. The identificati...
Article
In this article we propose an efficient and accurate model to estimate peak-to-peak core switching noise, caused by simultaneous switching of logic loads along a vertical chain of power distribution TSV pairs in a 3D stack of dies interconnected through TSVs. The proposed model is accurate with only a 2–3% difference in peak-to-peak core switching...
Conference Paper
A content-extraction based acceleration data compression algorithm is proposed for real-time transport quality monitoring in critical logistics applications. It splits the original data into three components, Tilt, Shock and Vibration, and compresses them separately by making use of the specific characteristics. Outstanding performances as well as...
Conference Paper
Full-text available
Quantifying environmental footprint is an important task for the embedded system researcher as this study keep them aware of environmental impacts' threat toward green and healthy living of human beings. In this work we have presented a study on analysis of sustainability and environmental impacts assessment in manufacturing process of rigid substr...
Article
The novel idea of integrating Radio Frequency Identification (RFID) with sensors along with other wireless applications by using single tag antenna is implemented, by fabricating proposed antenna using state-of-the-art inkjet printing technology on commercially available paper substrates. For the first time, a parametric analysis is performed for r...
Article
This paper presents the investigation of the resistive humidity-sensing properties of multi-walled carbon nanotubes (MWCNTs). MWCNTs functionalized by acid treatment (f-MWCNTs) exhibit rather high sensitivity in resistance toward humidity, owing to the presence of carboxylic groups on the nanotube surface. By integrating the f-MWCNTs resistor into...
Article
Full-text available
In this work end-of-life (EOL) analysis of polymer and paper based radio frequency devices have been carried out. Polymer and paper based RFID antenna has been chosen as a radio frequency device. An attempt has been made to investigate and evaluate the environmental emissions at end-of-life-cycle stage and to explore type and quantity of emissions...
Conference Paper
Full-text available
This paper aims to give an insight into the importance of green ICT course in the curriculum of Master and PhD level studies. An attempt has been made to demonstrate its necessity, implementation issues and strategic plans to execute this course. General structural plans along with details of the course content are discussed in this paper. The cour...
Article
Full-text available
Printed antennas based on glass epoxy substrate have been developed. On the basis of required specifications and assigned frequencies, tip-truncated triangular printed antennas have been designed, analyzed, and fabricated. The performances of the antennas have been measured in terms of return loss, frequency of operation, bandwidth, and radiation p...
Article
Full-text available
A balance optimization method has been employed to determine the quantity of toxic emissions particularly in emissions to air, fresh water, sea water and industrial soil, in production process of polymer and paper based RFID tags. We have developed a low profile antenna design for passive UHF RFID tags using both polymer and paper substrate with co...
Article
The revolution of Internet-of-Things (IoT) is reshaping the modern food supply chains with promising business prospects. To be successful in practice, the IoT solutions should create “income-centric” values beyond the conventional “traceability-centric” values. To accomplish what we promised to users, sensor portfolios and information fusion must c...
Article
Full-text available
E-Mails: analc@kth.se (A.L.C.); qiangch@kth.se (Q.C.); lirong@kth.se (L.-R.Z.) Abstract: Significant influence on the thermal stability of polyaniline (PANI) in the presence of multi-walled carbon nanotubes (MWCNTs) is reported. By means of in-situ rapid mixing approach, water-dispersible nanofibrillar PANI and composites, consisting of MWCNTs unif...
Article
Full-text available
In this work cradle to grave life cycle assessment of printed electronics resources have been presented. An attempt has been made to investigate and evaluate the life cycle assessment and environmental impacts of printed electronics resources such as polymer substrate-printed RFID antenna. Life cycle inventory analysis for these resources has been...
Article
In dense passive radio frequency identification (RFID) systems, code division multiple access (CDMA) techniques can be used to alleviate severe collisions and thus enhance the system performance. However, conventional CDMA techniques are challenging to implement, especially for passive tags due to cost and power constraints. In this paper, we desig...
Article
The development of low cost directly printable RFID tag antennas is essential for item level tracking. We present evolutionary design approach to achieve robust extremely versatile RFID antennas on paper/flexible substrates which allow a simple integration directly on, e.g., paperboard in a roll-to-roll production line. Fully integrated printed tag...
Article
This article presents the design and implementation of a chipless radio frequency identification (RFID) tag on flexible substrate.The tag is designed based on the sympathetic oscillations of multiple LC (inductor–capacitor) circuits that possess distinct resonant frequencies. Information is encoded by controlling placement of these resonant frequen...
Article
Full-text available
In this paper, novel Bowtie antennas which cover complete UHF RFID band (860–960 MHz), fabricated on various ultra-low-cost substrates using state-of-the-art printing technologies are investigated as an approach that aims to accommodate the antenna during the package printing process whilst faster production on commercially available paper. The pro...
Article
Full-text available
A parametric analysis is performed for a wideband Archimedean spiral antenna in recognition of an emerging concept to integrate RFID along with several applications by using a single antenna. The antenna is fabricated using state-of-the-art inkjet printing technology on various commercially available paper substrates to provide the low-cost, flexib...
Article
Full-text available
Fully integrated printed RFID antennas show potential solution for item level labeling applications. In order to accommodate the antenna during the package printing process, it is vastly preferred that antenna structures are printed on paper substrates. However, the electromagnetic properties and thickness of paper substrates are susceptible to cha...
Conference Paper
The present state of the art research in the direction of embedded systems demonstrate that analysis of life-cycle, sustainability and environmental assessment have not been a core focus for researchers. To maximize a researcher's contribution in formulating environmentally friendly products, devising green manufacturing processes and services, the...
Article
The 3D-DRAM stacked over the processor is a vibrant technique in order to overcome the memory wall as well as the bandwidth wall problems. We considered a system with two DRAM dies over a single processor die. We assumed the decoupling capacitors to be placed on each DRAM die and connected to the power distribution TSV pairs, where the TSVs pass th...
Article
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 config...
Conference Paper
This paper presents electrical performance of paper based inkjet printed flexible cable for wearable electrocardiogram (ECG) monitoring. The cable is fabricated by inkjet printing of nano-silver wires on paper which connect bio-electric electrodes with wireless transmission of ECG signals to the central medical device. The cable consists of printed...
Conference Paper
This paper proposes a novel printable multi-functional passive sensor for remote monitoring. The sensor mainly consists of a series of pairs of transmission lines and sensing resistors whose resistances vary with one physical parameter. A short-duration radio frequency pulse as interrogation signal travels along the transmission line and is partial...
Conference Paper
The low conductivity and thin layers of the inkjet-printed metal conductors have always been a big concern in paper-based printed electronics for high frequency applications. To provide the fundamental knowledge, the high frequency characteristics of inkjet-printed coplanar waveguides on paper substrate were studied experimentally in terms of chara...
Article
Thin-film field-effect transistors (TFTs) are readily fabricated using a semiconductor composite that is solution processed under ambient conditions for the conduction channel. The composite comprises single-walled carbon nanotubes (SWCNTs) embedded in poly-9,9<sup>'</sup> dioctyl-fluorene-co-bithiophene. Carrier mobility values approaching 10 cm<s...
Article
Full-text available
Maximizing electrical energy generation through waste heat recovery is one of the modern research questions within automotive applications of thermoelectric (TE) technologies. This paper proposes a novel concept of distributed multisection multilevel DC–DC conversion networks based on thermoelectric generators (TEGs) for automotive applications. Th...
Article
This paper reports on the development of a 10-bit chipless RFID tag on flexible plastic substrate. This tag is based on sympathetic oscillations of a group of LC circuits with different resonant frequencies. Sophisticated designs including the placement of capacitors involved in each LC circuit, and various LC combinations are examined for the trad...
Article
The development of RFID technology are requiring high performance and low cost tag antennas than ever before. To meet these demands, linear tapering technique is firstly proposed in the design of planar tag antennas. With this strategy, the current distribution along antenna arms is effectively assigned by varying the antenna line width. Compared w...
Article
Supply grids of integrated chips are interconnected through through-silicon vias (TSVs) in modern design techniques to form a 3-D stack in vertical direction. The load on each chip is supplied through (power/ground) TSV pairs. Accurate estimation of power/ground noise on each TSV pair of a 3-D power distribu- tion network is necessary for a robust...
Conference Paper
Full-text available
Simulations are widely used to design and evaluate new protocols and applications of indoor wireless networks. However, the available network simulation tools face the challenges of providing accurate indoor channel models, three-dimensional (3-D) models, model portability, and effective validation. In order to overcome these challenges, this paper...
Chapter
Food chain visibility and safety problems have caused huge loss of money and threat to public food safety. The blooming Wireless Sensor Network (WSN) technology has been highlighted as a promising solution to resolve these problems. Because nowadays food chains has become highly distributed, heterogeneous, cooperative, and globalized, a comprehensi...