Looking to use RFID tags for your business or warehouse? Interested in the technology now that you found an RFID jamming card for travel? One of the most important parts of RFID technology is the range. How far can RFID be read, and how does that range affect its applications? Let’s find out.
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What is RFID?
RFID is short for “radio frequency identification,” which is a kind of technology that allows for tags and labels to be read using radio waves. This kind of technology is also known as Automatic Identification and Data Capture (AIDC). AIDC technology helps collect data on objects and then identifies those objects accurately.
RFID is like a barcode, but that is where the similarities stop. The notable difference between RFID and barcode technology is that you can read RFID tag data outside the line of sight. Barcodes, on the other hand, must be near the optical scanner.
RFID systems are made of three parts: the tag or label, an antenna, and the RFID reader. RFID tags each have a circuit and antenna for transmitting data that is picked up by the RFID reader.
How is RFID Used?
RFID technology is fascinating and has numerous applications that range from product tracking to identifying lost animals, and transportation. For industrial applications, RFID tags are used for logistical purposes, as well as automation.
There are three groups of RFID tags: Low frequency (LF) tags, high frequency (HF) tags, and ultra-high frequency (UHF) RFID tags. Each group has its own uses and benefits.
Different Kinds of RFID
As mentioned above, there are three different groups of frequencies used. There is also a variety of RFID tags: passive, battery-assisted passive/semi-active, and active tags. The first, passive tags, are powered by the RFID scanner’s magnetic field emissions, which send a current through the tag’s antenna. This makes passive RFID tags the cheapest form of this technology.
Battery-assisted passive (BAP) tags have a battery that is integrated into the circuitry. Signals are not sent until the RFID reader is triggered.
Active tags will consistently emit signals to the RFID reader. Active RFID tags are constructed with a battery or other power source that allows them to transmit and receive signals throughout the day. The amount of data that can be held and transmitted is dependent on the size of the tag. The average is around a couple of thousand bytes of data.
Both BAP and active RFID tags have a longer range than passive tags.
How Far Can RFID Be Read?
Now that you know about the different kinds of RFID tags, let’s talk about how the frequency of the tag influences its range.
Low-frequency tags cover the range between 30-300 kHz. LF RFID tags are known to have the shortest range—around 10 centimeters between the tag and the reader. Since the radio waves are of a lower frequency, the read time is slow, too. The benefit of using low-frequency RFID is the lack of radio interference.
Should the tag be an LF passive, it is considered a “near-field tag,” meaning that it is read within a single wavelength from the scanner. The range cannot be expanded.
One of the main issues with LF tags is that they are not compatible globally. This is due to the different power levels and frequencies used throughout the world. LF RFID is commonly used for access control and animal microchipping.
HF RFID is the most commonly used range—between 3-30 MHz. Most tags function at 13.56 MHz, which has a moderate level of radio interference. On average, high-frequency RFID can be read between 10 centimeters (3 inches) to 1 meter (around 3.28 feet).
There are several uses for high-frequency RFID, including Near Field Communication (NFC). Think tapping your debit card to pay for your groceries. Other ways high-frequency RFID is used are in tracking purposes, waste management, manufacturing, health and medical, and payment or cataloging.
HF RFID tags are available in a range of shapes and sizes for all kinds of applications.
Ultra-High Frequency RFID
Looking for the longest read range and fastest speeds? Ultra-high frequency RFID tags are available in both near-range and far-range types. Compared to regular HF tags, near-range UHF tags have a narrower range. The benefit to using them is the lack of interference, increasing performance.
Far-range ultra-high frequency RFID in a passive tag can be read about 12 meters (39 feet) away. Active UHF tags can reach a range of up to 100 meters (328 feet).
The operating frequency of this kind of RFID tag is between 300 MHz and 3 GHz. Because of this, UHF tags are highly susceptible to radio interference. To counteract this, manufacturers make antenna and readers specific to their brand.
Interestingly, UHF tags are easier and cheaper to make than HF tags, which has led to these tags being used for a broad range of things, including inventory management, wireless device configuration, and more.
Nearly all keyless entry car systems use Ultra-high frequency RFID signals, unfortunately, this can lead to relay attacks and car theft.
How far can RFID be read? It depends on the kind of tag used. Low-frequency tags rarely get past 3-4 inches, especially if the tag is passive. Active tags for both high and ultra-high frequencies can reach much, much farther. HF tags may reach up to 3-4 feet, and UHF has a range of 20-330 feet! Perhaps it is time to invest in an RFID blocking wallet?