RFID is a tracking system that uses electromagnetic fields and is transforming workflows across a variety of industries. The supply chain sector, in particular, is seeing significant benefits from this reliable and efficient method. With remarkable advancements in recent years, RFID technology continues to grow in prominence due to its numerous advantages.

As more operations and industries adopt RFID tags for tracking, these tools are becoming increasingly effective across diverse settings. Understanding the different types of tags, readers, and technology available—as well as the applications that benefit most from their use—is key to leveraging the full potential of RFID.

We provide a thorough overview of how RFID works, as well as insight into which types of RFID tags best fit specific use cases.

What Is RFID?

The term RFID (radio frequency identification) refers to an advanced form of wireless technology that uses radio waves to capture information. This technology allows users to automatically identify objects or individuals, making it a valuable tool for inventory management, asset tracking, and other supply chain applications.

Readers and tags are the two primary components that work together to facilitate data exchange and power RFID solutions. Sometimes referred to as an interrogator, the RFID reader includes integrated circuits (microchips) and antennae and is used to receive tag data. The tags are affixed to the items that they are intended to track and hold electronically stored data that the reader will receive.

How Do RFID Tags Work?

The antenna in an RFID tag is designed to receive signals from the reader and serve as a unique identifier, while the circuit processes and stores critical information.

Once the tags have been attached to their intended objects or people, they use electronic chips to communicate with their connected readers. Unlike other technologies, these tags do not require direct line-of-sight visibility from the tag to the reader, and multiple tags can be scanned simultaneously. This transmitted data takes the form of radio waves, which are received by the RFID reader and converted into useful information. The stored data is then transmitted through a specialized interface, where computer systems and software analyze and back up the information.

The tags’ pieces, the aforementioned circuits and antennae, are held together via a specially designed protective material. The type of material used can vary somewhat based on the application. While glass was originally one of the most common materials relied upon for these systems, today’s tags often feature plastic or silicone.

Types of RFID Tags

Over the years, RFID tags have taken many forms. Initially, they were inductively coupled and made up of systems featuring metal coils, antennae, and glass. In an effort to reduce expenses, capacitively coupled tags were introduced, replacing metal coils with conductive carbon ink.

While all tags share the same general function, they fall under the umbrella of several categories. RFID tags are primarily classified by frequency and power source.

Frequency Differences

Frequency bands play a critical role in tag selection. Four main categories fall within the Industrial, Scientific, And Medical (ISM) radio bands. Tags are generally chosen based on the materials that make up the objects being tracked. Metal and water content, in particular, tend to impact tags differently based on the frequency with which they operate.

The following are the main frequencies available for RFID systems:

• Low-frequency (LF). While LF systems typically involve under 134.2 kHz, this band comprises the vast frequency range of 30 kHz to 300 kHz. Data read rates tend to be slow for LF solutions, but these systems are uniquely useful for operating near metal or liquid. Low frequency systems are also popular for access control and point-of-sale checkout.
• High-frequency (HF). Featuring a read range of between one and three feet, high-frequency systems span between 3 and 30 MHz. Mostly, however, these systems operate at or near 13.56 MHz. Their applications tend to be limited within the supply chain industry, but they can be useful for other functions such as credit card security and ticketing.
• Ultra-high-frequency (UHF). This broad portion of the radio frequency spectrum can span anywhere from 300 MHz to 3 GHz. In general, however, UHF systems operate somewhere between 860 and 960 MHz. UHF systems are typically the preferred option for supply chain and logistics applications, as they boast an impressive read range.
• Near field communication (NFC). Based on RFID protocol, NFC devices are capable of acting as both tags and readers. They generally operate on a system resembling HF solutions. They’re typically situated within close proximity of one another and are preferred for maintaining secure communications.

Active vs Passive RFID Tags

In addition to frequency classifications, tags can be categorized as active or passive (which refers to how they are powered).

Passive RFID tags do not contain their own power sources and, instead, rely on radio waves received from readers. Although less convenient in some circumstances, this lack of a power source can be beneficial in that it prevents contributions to radio noise. Passive devices also tend to cost less than their active counterparts.

Active RFID tags feature onboard power sources such as batteries. This grants them greater processing power, and often, more impressive read ranges. They’re less useful with small items, however, and may require a greater financial commitment. Active tags are also distinguished by their inclusion of onboard transmitters, which are capable of sending energy directly to readers.

Semi-passive tags provide an excellent middle ground between active and passive solutions. Like active tags, they contain batteries. They do not, however, have onboard transmitters. While battery usage limits tag lifespan, semi-passive tags can still be a cost-effective alternative when active tags are unnecessary.

Benefits of RFID Technology

Used correctly, RFID can provide a wide range of benefits, many of which promise to improve efficiency and profits within the supply chain sector. Key advantages are outlined below:

• Real-Time Visibility – From personnel to assets, these systems offer a unique level of visibility difficult to achieve with other tracking options. Real-time tracking improves traceability and provides immediate access to critical data. This can be used to make informed decisions promptly.
• Increased Efficiency – These systems reduce reliance on manual data entry, which is not only prone to human error, but also, notoriously inefficient. The data produced and transferred via this technology can quickly be received, analyzed, and stored. On a long-term basis, this can lead to significant savings in terms of both time and money.
• Avoiding Losses For Business-Critical Assets – The increased accuracy reduces the risk of loss when moving or otherwise handling business-critical assets. These losses often occur due to misrouting, which, under an efficient system with real-time visibility, is less likely to occur. RFID security solutions can also be deployed to reduce the risk of theft. 

What are RFID Tags Used For?

This type of technology has been versatile from the very beginning. Experts trace the technology’s history back to World War II, when identification friend or foe (IFF) systems paired plane-based transmitters with radar stations to broadcast signals determining whether aircraft were “friendly.”

Soon after, similar radio frequency systems took on anti-theft applications resembling the electronic article surveillance tags still used among retailers today. In the early 2000s, Wal-Mart attracted attention by implementing RFID for pallets in the United States. Eventually, a variety of retailers began to use it for warehousing and in stores.

These systems have evolved significantly over time, expanding their range of applications. Common RFID use cases within the supply chain industry include:

• Shipment verification. Things move quickly in a global marketplace. As shipments move globally, distribution centers and ports need to operate at optimal efficiency to ensure goods reach the correct destination. Manual tracking of inbound and outbound shipments can no longer keep pace with the speed of business or navigate disruptions.
• Inventory management. Used to track inventory in real-time, RFID tags improve efficiency for stocking while also minimizing the potential for counting errors or even theft. These purposes are increasingly served by item-level tracking.
• Asset tracking. The prompt data collection made possible by the tags makes these systems valuable for tracking high-value assets in an efficient and accurate manner.
• Personnel tracking. While the tags are typically associated with inventory and assets, they can also be used to provide useful data about personnel. These systems enhance employee safety while also promoting greater productivity.
• Access control. The technology can be used to secure spaces by only granting access to authorized individuals. This solution can be easily be customized to limit access based on a variety of parameters while keeping security costs manageable.
• Supply chain management. The versatile nature of the tags allows them to deliver impressive oversight for a variety of supply chain functions and processes. These systems can be applied to resolve some of the supply chain industry’s most significant concerns, including working capital, operational costs, and compliance.

While the RFID systems are uniquely versatile, they are not ideal for use in all supply chain applications. The tags may be durable and secure, but barcoding technology tends to still be more affordable and easier to implement in some cases. That said, RFID is becoming increasingly affordable as adoption grows and the technology gains wider use.

Furthermore, material limitations are less likely to come into play with barcode labels, which generally do not become unreadable upon encountering specific types of items or their contents. Hence, the preference for barcodes in grocery stores, where metal carts would not yield accurate scans if RFID systems were incorporated.

Find the Right RFID Solution with Peak Technologies

With proper planning and implementation, RFID technology can provide an impressive tracking solution that stands up to both general wear and modern security concerns. This versatile solution can be applied in a variety of industries, where it holds the potential to drive both efficiency and innovation.

If implemented incorrectly, RFID may provide limited returns on investment. For this reason, deployment should be directed by an expert service provider with a thorough understanding of the technology — and the ability to customize it to fit specific purposes.

Peak Technologies’ RFID services provide a variety of advantages for supply chain systems. If you’re ready to move forward and learn more about the technology, discuss your options with one of our specialists today.