Zhuo Zou

A remote-powered RFID tag with 10Mb/s UWB uplink and −18.5dBm sensitivity UHF downlink in 0.18µm CMOS

Wireless sensing and positioning are new added functions, highly demanded, in future and emerging RFID technology [1]. The data rate of existing passive RFID tags is limited to a few hundreds of kb/s causing large latency. On the other hand, the position accuracy is not better than 70cm [2]. In an advanced design, a 3.4Mb/s data rate has been achieved in proximity operation [3]. Active tags with a narrowband radio link overcome these weaknesses, but, they are battery powered and more expensive.

A Low-Power and Flexible Energy Detection IR-UWB Receiver for RFID and Wireless Sensor Networks

This paper presents an energy detection Impulse Radio Ultra-Wideband (IR-UWB) receiver for Radio Frequency Identification (RFID) and Wireless Sensor Networks (WSN) applications. An Application-Specific Integrated Circuit (ASIC) consisting of a 3-5 GHz analog front-end, a timing circuit and a high speed baseband controller is implemented in a 90 nm standard CMOS technology. A Field-Programmable Gate Array (FPGA) is employed as a reconfigurable back-end, enabling adaptive baseband algorithms and ranging estimations. The proposed architecture is featured by high flexibility that adopts a wide range of pulse rate (512 kHz-33 MHz), processing gain (0-18 dB), correlation schemes, synchronization algorithms, and modulation schemes (PPM/OOK). The receiver prototype was fabricated and measured. The power consumption of the ASIC is 16.3 mW at 1 V power supply, which promises a minimal energy consumption of 0.5 nJ/bit. The whole link is evaluated together with a UWB RFID tag. Bit error rate (BER) measurement displays a sensitivity of -79 dBm at 10 Mb/s with 10-3 BER achieved by the proposed receiver, corresponding to an operation distance over 10 meters under the FCC regulation.

A Novel Passive Tag with Asymmetric Wireless Link for RFID and WSN Applications

In this paper, we present a radio-powered module with asymmetric wireless link utilizing ultra wideband radio system for RFID and wireless sensor applications. Our contribution includes using two different standards in uplink and downlink. Such as conventional RFIDs, incoming RF signal transmitted by reader is used to power the internal circuitry and receive the data. However, in upstream link, an IR-UWB transmitter is utilized. Unlike traditional RFID systems, due to great advantages of UWB communication, this tag is very robust to multi-path fading and collision problem and it is more secure against eavesdropping or jamming. The module consists of a power scavenging unit, a RF receiver, an IR-UWB transmitter, digital baseband controller, and an embedded UWB antenna are designed for integration on liquid-crystal polymer (LCP) substrate, using 0.18mum CMOS process technology.

A 2.4-GHz ISM RF and UWB hybrid RFID real-time locating system for industrial enterprise Internet of Things

ABSTRACT 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 coarse positioning in non-critical sites. The specified communication protocol and the adaptive tag synchronisation rate ensure reliable and deterministic access with a scalable system capacity and avoid unpredictable latency and additional energy consumption of retransmissions due to collisions. The tag, consisting of a commercial 2.4-GHz transceiver and a customised application-specific integrated circuit (ASIC) UWB transmitter (Tx), is able to achieve up to 3 years’ battery life at 1600 tags per position update second with 1000 mAh battery in one cluster. The time difference of arrival (TDoA)–based positioning experiment at UWB radio is performed on the designed software-defined radio (SDR) platform.

A 90nm CMOS UHF/UWB asymmetric transceiver for RFID readers

This paper presents an integrated asymmetric transceiver in 90nm CMOS technology for RFID reader. The proposed reader uses UHF transmitter to power up and inventory the tags. In the reverse link, a non-coherent Ultra-wide Band (UWB) receiver is deployed for data reception with high throughput and ranging capability. The transmitter delivers 160 kb/s ASK modulated data by an integrated modulator and a Digital Controlled Oscillator (DCO) in UHF band with 11% tuning range. The DCO consume 6 mW with 0.12 mm2 area. On the other side, adopting two integration channels, the 3–5 GHz energy detection receiver supports maximum 33 Mb/s data rate both in OOK and PPM modulations. The receiver front-end provides 59 dB voltage gain and 8.5 dB noise figure (NF). Measurement results shows that the receiver achieves an input sensitivity of −79 dBm at 10 Mb/s, with power consumption of 15.5 mW.

Food quality and safety monitoring using gas sensor array in intelligent packaging

This paper aims to study different possibilities for implementing easy-to-use and cost-effective micro-systems to detect and trace expelled gases from rotten food. The paper covers various radio-frequency identification (RFID) technologies and gas sensors as the two promoting feasibilities for the tracing of packaged food. Monitoring and maintaining quality and safety of food in transport and storage from producer to consumer are the most important concerns in food industry. Many toxin gases, even in parts per billion ranges, are produced from corrupted and rotten food and can endanger the consumers’ health. To overcome the issues, intelligent traceability of food products, specifically the packaged ones, in terms of temperature, humidity, atmospheric conditions, etc., has been paid attention to by many researchers.,Contaminated food is usually detectable by odor. A small gas sensors and low-cost tailored to the type of food packaging and a communication device for transmitting alarm output to the consumer are key factors in achieving intelligent packaging.,Conducting polymer composite, intrinsically conducting polymer and metal oxide conductivity gas sensors, metal–oxide–semiconductor field-effect transistor (MOSFET) gas sensors offer excellent discrimination and lead the way for a new generation of “smart sensors” which will mould the future commercial markets for gas sensors.,Small size, low power consumption, short response time, wide operating temperature, high efficiency and small area are most important features of introduced system for using in package food.

Energy detection receiver with TOA estimation enabling positioning in passive UWB-RFID system

This paper presents a passive UWB-RFID system with Time-Difference-of-Arrival (TDOA) positioning from system to circuit perspectives. Wireless powered RFID tags with UWB transmitter transmit wideband pulses to readers, allowing high accurate Time-of-Arrival (TOA) estimation. Low power low complexity TOA estimations using energy detection receiver are investigated. Max Energy Select (MES), Threshold Comparison (TC), and MES-Search-Back (MES-SB) algorithms are evaluated and analyzed. As a special focus, a prototype of the proposed energy detection receiver is designed and implemented. It consists of a 3.1–4.8GHz IR-UWB analog frontend with high speed digital circuits in 90nm CMOS, and a flexible back-end with a TOA estimator on FPGA.

Design and demonstration of passive UWB RFIDs: Chipless versus chip solutions

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 identification number is coded by variations of the impedance over the transmission line, resulting in the OOK modulated data by means of pulse reflections in time domain. Prototypes were fabricated and measured for 4-bit tag and 8-bit tag, respectively. Thanks to the employment of fully printing process and paper substrates, the tag is potentially ultra-low cost in volume production. Second, a wirelessly powered RFID tag with an active UWB transmitter is studied for advanced applications such as wireless positioning and sensing. The tag is powered by UHF continuous waves, whereas it uses an UWB pulse generator to transmit data to the reader. It ensures the improved coverage and accurate positioning over traditional backscattering UHF tags. UWB readers, positioning, and sensing are also discussed in a system perspective. The two solutions reveal that UWB is a viable alternative to existing passive RFIDs adapting both low-cost applications and high-performance sensing and positioning applications.

Impulse UWB energy detection receiver with energy offset synchronization scheme

Impulse ultra-wideband radios (IR-UWB) show strong advantages in low power and low cost applications such as RFIDs and wireless sensor networks. This paper presents an IR-UWB receiver based on Energy Detection (ED) with on-off keying (OOK) modulation. A novel synchronization and detection algorithm using the energy offset scheme with adaptive threshold detection is suggested, aiming to reduce energy consumption and simplify hardware complexity. Simulation and FPGA implementation reveal that the proposed method can avoid complex and power consuming synchronization blocks, and reduce the preamble length, whereas maintaining the performance in the target level. Hardware integration issues are discussed, implying that the proposed receiver architecture has the possibility to achieve low complexity and low power implementation with several nJs energy per bit, at a data rate of 10Mb/s.

Baseband design for passive semi-UWB wireless sensor and identification systems

This paper presents a digital baseband design for passive sensor and identification systems using asymmetric wireless links with ultra wideband (UWB) radio. As opposed to traditional wireless sensor and identification systems using half-duplex communication in narrowband frequency, impulse-UWB is applied as an uplink in the proposed system. A novel baseband protocol is devised to improve the system efficiency in the multi-tag environment while maintaining the power constraint. By utilizing adaptive slotted ALOHA anti-collision algorithm, 1000 tags can be processed within 500ms. The contributions also include the development of a low-power digital baseband processor for passive tags. The simulation is successful and the FPGA prototype is operational. The chip is implemented for ASIC and it will be fabricated and tested with the front-end in 1P6M UMC 0.18μm process.