Variable Tools for a Variety of Tasks
Radio frequency identification (RFID) technology has become much more common in recent years, and now can be found across virtually every industry. However, it’s far from homogeneous. With various types of RFID tags available, organizations can identify which ones will suit them best as each brings strengths to different types of applications.
At its core, RFID uses electromagnetic fields to automatically identify and track tags attached to objects. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number or electronic product code, back to the reader. This number can be used to track inventory goods.
The applications and industries using this technology to manage inventory or processes are growing. You can use RFID to track documents, from their creation to their endpoint. An RFID tag attached during production — for an automobile or a computer, for example — can be used to track its progress through an assembly line.
But not every tag will be the right fit for every application. The types of RFID tags include differences in the radio frequency they use to communicate (low, high, or ultra-high) and how the tag communicates with the RFID reader (active or passive). Today we’ll examine each of these differences, highlight their specifics and discuss the kinds of applications for which they might be best put to use.
Frequency Types of RFID Tags
RFID tags can be grouped into three categories based on the range of frequencies they use to transmit data. Frequency refers to the size of the radio waves used to communicate between components in the RFID system. These categories include low frequency (LF), high frequency (HF), and ultra-high frequency (UHF).
In general, the lower the frequency of an RFID system, the shorter the read range and slower the data read rate. But there are tradeoffs. A low frequency may have a slower read rate but has better read capabilities near or on metal or liquid surfaces. A higher frequency may have a better range and speed but is more prone to disruption by metal or liquids in the vicinity. Let’s look closer at each of the frequency ranges.
LF RFID systems operate in the 30 kHz to 300 kHz range and can read up to a range of approximately 10 cm. The longer wavelengths at these frequencies, including commonly used bands at 125 kHz and 134 kHz, offer more resilience to radio wave interference from metals or water in the environment.
Because of this resistance, LF tags are often used in applications where an RFID tag is affixed to a metal substrate — like an automobile assembly line or inventorying beer kegs. The short read range also leads to natural usage in applications like livestock tracking and access control (doors and gates), where the range is a non-issue or where having the two elements close together (e.g., secured building access) is desired.
RFID tags in this category operate in the 3 MHz to 30 MHz range and offer potential reading distances of 10 cm to 1 meter (39.4 inches). Most HF RFID tags and systems operate at 13.56 MHz and experience moderate sensitivity to radio interference.
A subset of HF RFID tags is Near Field Communication (NFC) tags. All NFC tags are HF tags, but not all HF tags fall into the NFC category. NFC tags have a much smaller read range — just a couple of centimeters — and while entire groups of HF tags can be read at once, NFC tags must be read one at a time. NFC tags provide secure one-to-one connections, making them useful for contactless payment applications like ApplePay(™). Because nearly all smartphones function as NFC readers, NFC tags are often used in promotional labels and posters to power personalized customer engagement.
HF tags have a variety of uses, from cataloging library media to tracking bracelets in theme parks. Other common applications include electronic ticketing, payment, and data transfer.
UHF tags and systems operate at frequencies between 300 MHz and 3 GHz, boast faster data transfer rates, and can be read at ranges of up to 12 meters (nearly 40 feet). While these tags are more sensitive to interference, they are less expensive to produce and remain the go-to choice for inventory tracking (and other) applications where a large number of tags are required.
Whether it’s item-level tracking, retail inventory control, returnable container tracking, or other supply chain efficiency measures, UHF tags will be the type most organizations turn to for large-scale implementation. Hundreds of tags can be read simultaneously, saving time and money in manual inventory management as entire truckloads of products can be counted at once.
Communication Types of RFID Tags
RFID tags and systems operate within specified segments, in addition to the frequency classifications. These include Active and Passive.
Active RFID tags have their own transmitter and power source (typically a battery) on the tag itself. Usually, Active RFID tags fall into the UHF range and can extend up to 100 meters in some instances. Active tags are more expensive than their passive counterparts and are used to track large or extremely valuable assets like rail cars, big reusable containers, vehicles, and machines.
Active RFID tags will be equipped with either a transponder or beacon transmitter and often include sensors to measure and transmit temperature, humidity, shock/vibration, and other data for the objects they’re attached to. Transponders only transmit data when they receive a signal from a reader (like a toll payment or control checkpoint), while beacons emit a signal at preset intervals and are used to track items in real-time location systems (wheelchairs in a hospital or cargo containers at a shipping dock).
Passive RFID tags, however, remain dormant until they receive a signal from a reader. The energy from the reader’s signal is used to ‘activate’ the tag and reflect an information-carrying signal to the reader. These tags require only a chip and an antenna, making them more cost-effective, smaller, and easier to manufacture than their active tag counterparts. Passive RFID systems can operate in any of the frequency ranges, although they’re often paired with UHF ranges to enhance their widespread use for product and pallet labels.
The Kennedy Group shines in the realm of passive RFID tags. With RFID tags designed specifically for retail items, documents, and multiple-trip or durable warehouse applications, we provide solutions to help you tighten up and streamline your inventory processes. Our Smart Placards® and Smart Nameplates® ensure that your containers and racks are all accounted for. Our SmartCard™ Tags are durable and made to handle extreme elements. They have changed tracking for the air conditioning market. But RFID tracking doesn’t end in your warehouse. Our SmartAsset retail tags help you track your inventory in your store and our SmartTherm™ Tags help you track important documents and files and boxes.
Lean on The Kennedy Group for RFID Solutions
With nearly 50 years of providing innovative solutions for packaging and labeling needs, The Kennedy Group’s long history of finding unique solutions to challenging problems is a strength in the current environment. Every organization is exploring options to streamline and create more efficiency in inventory and warehouse management operations; the experts at The Kennedy Group can help.
Connect with The Kennedy Group today to learn more about our RFID solutions and how we can assist your team with asset management.