Multi-State Logging Freeze Detection Passive RFID Tags

In this work the design and measurement of a passive UHF RFID smart tag suitable for monitoring and recording critical temperature violations in cold chain management are presented. The tag uses moving parts to detect and log different temperate states without the requirement for transceivers, memory and batteries. A simple mechanical method is proposed whereby a moving metallic plate is trapped in one of 4 possible positions by specific environmental temperatures whereby inducing a permanent state based change in the passive RFID tag response. The latched product critical temperature violations can be monitored via the read power required to turn on the tag transponder chip which differs in each state

A Dual Band Belt Antenna

This paper presents an antenna structure design using a standard belt for wearable applications. The antenna arouse from a body of research work on wearable metallic structures functioning as antennas for wireless on-body networks

Tamper Proof RFID Security Tag

In this publication we present a tamper proof long range platform tolerant uhf smart RFID tag to identify valuable or security sensitive products. The smart tag functions as platform tolerant tag but once detached from the host object, it will permanently stop to function buy rendering the RFID chip unusable. The tag substrate design for additive manufacturing, platform tolerant antenna design as well as electromagnetic performance and read range are provided

Passive UHF RFID Tilt Sensor

In this paper we introduce a bio-axis passive wireless UHF RFID tilt sensor for applications such as to increase safety in warehouse environment and damage detection in consumer goods and where long term monitoring of the product is essential without the need to supply power to the sensors. Simulation and prototype testing indicate it is possible to detect and isolate tilting in 3 axes

Polydimethylsiloxane Substrates for passive UHFRFID Sensors

PDMS has previously shown to be a suitable substrate for UHF-RFID strain sensor tags due to their elastomer characteristics. However, PDMS has further properties such as polymer swelling which could be utilized in gas sensing. Macroporous PDMS sponges have been proposed as suitable substrates for passive gas sensors. Porous sponges were fabricated using sugar templates and their absorption capacity was investigated along with standard PDMS elastomers. Possible applications could include food package and air quality monitoring

Small Epidermal Antennas

Small magnetic loop antennas are proposed as skin transfer tattoos to overcome the efficiency limitations of human tissue and variability of detuning

Influence of substrate types and reflector proximities over a NDTC antenna

The influence of dissimilar substrates and reflector proximities over a newly developed Non-uniformly Distributed-Turns Coil (NDTC) antenna for High-Frequency (HF) Radio Frequency IDentification (RFID) applications is presented. In the study, the performance of the HF-RFID NDTC antenna over various substrates with deposited conductor thicknesses is conducted. In addition, the effect over a conceivably encountered reflector in the proximity of the antenna is considered. Insensitive reflection coefficient (S11) responses for different substrate permittivities were experienced and the diverse conductor types and thicknesses contributed to a compromised magnetic-field (H-field) and recalculated matching network. The matching network additionally preserves resonance when the antennas is in close proximity to the reflector and a predictable H-field response for the separation range is shown

A Framework for a Low Power on Body Real-Time Sensor System using UHF RFID

This paper details the use of an acceleration measuring system which can transmit in real-time sensor data through UHF RFID to a computer. Existing methods of real-time transmission of sensor data rely on power-intensive Bluetooth or Wi-Fi technologies which result in devices that require large bulky batteries, this causes the overall device size to be high and thus can potentially cause issue during use. By harnessing status flags within a specific UHF RFID chip and custom reader software conforming to the EPC GEN2 standard, continuous streaming data rates of 5.2KBps were achievable. These enhanced data rates were shown to be reliable up to a range of 2.4M with above 99.99% data integrity. The power consumption of this methodology was found to be below 2mW during full power continuous transmission. In summary this paper outlines and lays the foundation for the use of UHF RFID to deliver sub-2mW low latency, high reliability streaming methods within the domain of on body transmission

Compact UWB Monopole for Multilayer Applications

A novel compact, dual layer UWB monopole antenna is presented. This low profile ultra-wideband antenna is fed by a 50 ? shielded strip-line with an array of metal vias making the conducting walls. A printed disc monopole with a circular cut is the radiating element. The dual layer, shielded strip line feed allows for integration in multilayer technologies. The ultra-wideband, monopole characteristics of the antenna are confirmed experimentally

Comparison of 3D scanned human models for off-body communications using motion capture

Body area networks are complex to analyze as there are several channel mechanisms occurring simultaneously, i.e. environmental multipath together with body motion and close coupling between worn antennas and human tissue. Electromagnetic (EM) simulation is an important tool since not all studies can be done on a real human. In order to gain insight into off-body communication involving a worn antenna, this paper uses a 3D animated model obtained from a 3D surface scanner and a motion capture system for full wave simulation of channels at 2.45 and 5.5GHz. To evaluate if the model can represent body area radio channels in general, a comparison of S21 of the simulated model with measurements from 5 other models of similar height to the main test subject is presented