UHF RFID Tag for Asset Tracking
Ultra-high radiofrequency identification, or UHF RFID Tag, has become an increasingly popular technology for tracking assets. This system helps companies streamline critical business processes and maximize efficiency.
Screen-printed, flexible UHF RFID tags have been demonstrated on Kapton and cardboard.15,16 However, these tags have a large footprint and poor antenna performance under bending.
Traceability
The rapid expansion of e-commerce has driven the demand for traceability. The use of RFID-based item level tracing systems, paired with UHF technology, offers massive data in RFID Card real time, which is used to simplify production processes and improve operational efficiency. The system enables the tracking of goods and services from their source to the consumer. It also simplifies logistics, which increases productivity and profitability for businesses.
In this study, a controlled test environment has been realized in order to simulate the main steps of the pharmaceutical supply chain (items line, cases line and border gate). This makes it possible to carry out effective experimental campaigns for evaluating the performance of UHF RFID-based tracing systems, even under particularly stressed operating conditions.
The performance degradation problems caused by the application of UHF RFID tags to a blood bag have been evaluated, and their expected criticality confirmed. On this basis, a guideline for the electromagnetic design of new high-performance tags capable of overcoming these criticalities has been defined. Driven by these guidelines, an enhanced tag has been designed, realized and tested. Due to patent pending issues, its shape and the electromagnetic solutions adopted cannot be disclosed.
The results obtained confirm the effectiveness of the proposed enhanced tag. The measured input impedance of the antenna at 867 MHz is in good agreement with the simulated values. Moreover, the temperature measurements of the tag, compared with those of a reference probe, show increases and decreases that are well aligned with the reference value.
Inventory Management
Managing inventory is an ongoing challenge for any company. Whether it’s raw materials that are used to make a finished good or stock that is sold directly to customers, companies constantly need to update and track inventory to avoid theft, shipping delays, production interruptions, and other problems that can affect profitability.
RFID has been proven to improve inventory accuracy by up to 13% compared to traditional methods. It also simplifies the tracking of items with a high-level of variability, such as metal products and liquids (which can interfere with radio signals).
The ability to track items automatically – without line-of-sight scanning or manual data entry – means increased productivity, reduced labor costs, and fewer human errors. Additionally, handheld RFID tag readers are portable and easy to use – workers can use them with no need for special training or tools.
Some UHF RFID tags include a built-in temperature sensor, which is ideal for manufacturing and industrial applications. For example, an RFID tag embedded with a temperature sensor can be programmed to identify when a hydraulic hose is leaking, which allows engineers to easily locate the problem and fix it before it causes a costly production delay. Alternatively, screen-printed thermistors can be used on the tag’s antenna to provide a similar function, though this approach has less precision.
Access Control
The UHF RFID Tag’s long read range and low cost makes it a popular choice for many different applications. These include tracking assets, managing inventory, and enhancing security systems. The technology is also being used to support Internet of things deployments enabling sensor data such as temperature, movement and location to be transmitted wirelessly.
When a card or wristband enters the range of an RFID reader, the RF energy field from the reader energises an aerial made from copper wire within the chip. The aerial powers a circuit that reads the card’s ID number and sends it back to the reader, which can then confirm whether the card has been authorised for access.
Unlike passive tags, active tags contain a battery to power their own transmission of radio waves. They are “woken up” when they receive a signal from an RFID reader and proactively beacon at predetermined intervals, making them a useful tool for security.
Screen-printed UHF RFID tags with the same IC have been previously demonstrated on polyimide Kapton15 and on cardboard14, with the objective of chemical sensing and package tracking, respectively. In these references, the antennas are based on a dipole transmission line with a meander that optimises source impedance for the IC and improves performance for the RFID tag. These antennas have been subjected to bending tests (see Fig 2d) and found to remain functional even after repeated bending radii down to 24 mm for each of the two axes.
Security
Keeping venues secure takes time and manpower, but RFID technology makes it possible to monitor large amounts of data in real-time. High reading success rates allow for automated verification of patrons’ credentials, so UHF RFID Tag staff can move fast to ensure all guests are allowed inside or to a specific area.
Using a special chip with a locked serialized TID, UHF RFID tags can prevent cloning and other security breaches. A TID is an electronic identifier that provides unique information about a tag, such as its manufacturer and model number. This identifier is programmed and locked by the chip manufacturer to keep unauthorized users from copying it and cross-copying it into another tag to gain access.
To thwart hackers, UHF RFID tags have reserved memory that holds two passwords (access and kill) with 32-bits each. These passwords are transmitted between the tag and reader during the authentication process to keep data protected.
To validate an RFID tag, the sensor measures a change in the analog response of the chip. These changes are a function of the ambient temperature and the tag’s environmental conditions. The sensor data is collected by a commercially available UHF RFID generation 2 RFIC and integrated into the screen-printed flexible antennas of our label. Different printing techniques were tested to find the best method to fabricate these antennas.