Here we will cover the basics of RFID frequency to make your decision-making process more manageable. Before deciding what type of RFID systems to review and test in an RFID solution, it is essential to determine the application. One reason this is so critical is the properties of the RFID labels themselves. RFID-enhanced labels have specific properties based on the type of tags and the frequency on which they operate. We will review the frequencies and some of the behavioral properties of those tags in this post. But first, let’s talk briefly about what the term frequency means.
What does frequency mean?
When referring to operating frequency, we generally refer to it in hertz (usually kilohertz or megahertz). A hertz is the standard measurement of a wave cycle (radio waves in this case). Imagine an ocean wave with a peak and a trough. A hertz measures a wave cycle by beginning with the midpoint from where the wave started. The cycle continues to the peak, down through the trough, and back up to the midpoint.
Once the wave goes through the peak, trough, and hits its midpoint, it has completed a cycle. The frequency is the number of cycles a wave completes in a single second. A wave that completes one cycle in one second would have one hertz. So, a high-frequency tag with an operating frequency of 13.56 MHz (Megahertz) radiates a wave that cycles 13,560,000 times per second.
High frequency is only one of the three frequency levels, along with low frequency and ultra-high frequency. So, now that we know what frequency means let’s jump into the definitions of each type and how they are typically applied.
Low-Frequency tags
Low Frequency (LF) tags generally operate at 125–134 kilohertz, meaning they usually have slower data transfer rates than their high-frequency or ultra-high frequency counterparts.
In addition, the frequency platform requires that the object is close to the reader (generally a few centimeters to inches) and not quickly moving to transmit the data stored on the tag. The desire for faster data transfer and convenient scanning has led to a decline in the use of low-frequency RFID.
However, this type of tag has one significant benefit. RFID opaque materials such as water or metals do not deter low-frequency tags. Due to the ability to transmit through otherwise RFID opaque materials, this product category can be a good fit when the tagged object has a high water content or requires close interaction with metal. The ability to penetrate liquids makes LF tags a great fit to identify animals or fruit. Applications under this umbrella may also include Access Control systems.
High-Frequency tags
High Frequency (HF) tags operate at 13.56 megahertz. They are essentially the ‘Swiss army knife of the RFID world. They have data transfer rates acceptable for many uses, a wide range of storing capacities and read distances ranging from millimeters to meters.
Tags in this category can still operate on objects exposed to water and are often a good fit for tagging bottles or vials containing liquids. There is almost an infinite amount of tag size and memory combinations available to fit the needs of virtually any application. A protocol within HF called near-field communication (NFC) allows you to communicate with the tags using a smartphone.
Various real-world applications can leverage these benefits. From reagent tracking to mobile payment, the possibilities seem endless. This type of tag’s ability to interact with smartphones makes its category increasingly popular, with marketers attempting to tie digital interactions with the physical world.
Ultra-High Frequency (UHF) tags
The majority of UHF systems operate between 860 and 960 megahertz. The distances for UHF tags are usually measured in feet and meters. While the tags are an excellent fit for objects that require fast identification from a distance, the tags are significantly impacted by liquids.
Because of the distance, lower cost, and quick transfer rates that come with the UHF platform, this technology has become popular for industrial applications and organizations looking for logistical improvements.
However, warehouses and labs aren’t the only places you’ll find UHF. UHF has found its way into the world of sporting events, often used for race timing and keeping track of tickets for expensive sporting events.
As you can see, many options are out there, scratching the surface of the implications within the primary tag frequency groups. This is why working with a solutions provider can help ensure the right fit for your application needs.
