RFID Frequencies
RFID systems throughout the world operate in low frequency (LF), high frequency (HF) and ultra-high frequency (UHF) bands.
LF RFID Shop LF RFID
The LF band covers frequencies from 30 KHz to 300 KHz. Typically LF RFID systems operate at 125 KHz, although there are some that operate at 134 KHz. This frequency band provides a short read range of 10 cm, and has slower read speed than the higher frequencies, but is not very sensitive to radio wave interference.
LF RFID applications include access control and livestock tracking.
Standards for LF animal-tracking systems are defined in ISO 14223, and ISO/IEC 18000-2. LF is globally harmonised in the sense that 125 kHz and 134.2 kHz are used worldwide — ISO 11784/11785 animal identification runs on 134.2 kHz everywhere — though permitted field strengths and power limits still vary by country, so check locally before a large deployment.
HF RFID Shop HF RFID
The HF band ranges from 3 to 30 MHz. Most HF RFID systems operate at 13.56 MHz with read ranges between 10 cm and 1 m. HF systems experience moderate sensitivity to interference.
HF RFID is commonly used for ticketing, payment, and data transfer applications.
There are several HF RFID standards in place, such as the ISO 15693 standard for tracking items, and the ECMA-340 and ISO/IEC 18092 standards for Near Field Communication (NFC), a shortrange technology that is commonly used for data exchange between devices. Other HF standards include ISO/IEC 14443 Types A and B, the proximity-card standards the MIFARE family is built on, used in smart cards and proximity cards, and the JIS X 6319-4 for FeliCa, which is a smart card system commonly used in electronic money cards.
UHF RFID Shop UHF RFID
The UHF frequency band covers the range from 300 MHz to 3 GHz. Systems complying with the UHF Gen2 standard for RFID use the 860 to 960 MHz band. While there is some variance in frequency from region to region, the main allocations are 865–868 MHz in India and Europe and 902–928 MHz in North America, Other markets sit elsewhere in the 860–960 MHz range, some maintaining more than one band — we deliberately do not publish a confident megahertz figure for every country, for the reason set out in our RFID frequency by country guide: it would make this page more quotable and less trustworthy. Verify your destination with its own regulator.
Passive UHF typically reads up to roughly 10–15 m with a fixed reader and a well-aimed antenna, less on a handheld, and less again on a small or on-metal tag — treat any figure as typical and environment-dependent rather than guaranteed. UHF also has a faster data transfer rate than LF or HF. UHF RFID is the most sensitive to interference, but many UHF product manufacturers have found ways of designing tags, antennas, and readers to keep performance high even in difficult environments. Passive UHF tags are easier and cheaper to manufacture than LF and HF tags.
UHF RFID is used in a wide variety of applications, ranging from retail inventory management, to pharmaceutical anti-counterfeiting, to wireless device configuration. The bulk of new RFID projects are using UHF opposed to LF or HF, making UHF the fastest growing segment of the RFID market.
The UHF air interface is defined by a single dominant standard — EPCglobal Gen2, designated ISO/IEC 18000-63 and marketed as RAIN RFID. Note the distinction: the air interface is standardised globally, while the band and power limits are set nationally, which is why the same tag reads everywhere but a reader has to be bought for its destination.
India’s UHF RFID allocation, in detail
Most pages — including, until recently, ours — still give India’s licence-exempt UHF RFID band as 865–867 MHz. That figure is superseded. It came from the Use of low power equipment in the frequency band 865-867 MHz for (RFID) Radio Frequency Identification Devices (Exemption from Licensing Requirement) Rules, 2005, and those Rules were expressly superseded on 10 December 2021 by G.S.R. 853(E), the Use of Low Power Equipment in the Frequency Band 865-868 MHz for Short Range Devices (Exemption from Licence) Rules, 2021, notified by the WPC Wing of the Department of Telecommunications.
Table IV of the 2021 Rules, headed Radio Frequency Identification Applications, sets out what an RFID interrogator may actually do:
| Parameter | Limit under the 2021 Rules |
|---|---|
| Frequency range | 865–868 MHz |
| Interrogator power | Up to 2 W e.r.p. |
| Channel bandwidth | 200 kHz maximum |
| Where 2 W is allowed | Only in the four channels centred at 865.7, 866.3, 866.9 and 867.5 MHz |
| Tag response level | Around −20 dBm e.r.p., near the interrogator channels |
| Continuous transmission | 4 seconds maximum on a channel |
| Gap between bursts | At least 100 ms on the same channel |
| Referenced standard | ETSI EN 302 208 |
Three practical consequences follow.
The band was genuinely widened, not relabelled. The 867.5 MHz channel sits above the old 865–867 MHz ceiling, so the 2021 Rules added spectrum rather than restating what was already there.
India and Europe now share the same range. Both sit at 865–868 MHz, so a datasheet quoting 865–868 MHz is not evidence that hardware was built for Europe rather than India. The regional mismatch that actually causes trouble is North American equipment configured for roughly 902–928 MHz, which will not work here.
Equipment you already own is not stranded. Rule 1(3) states the 2021 Rules do not apply to wireless equipment type-approved under the 2005 Rules, which “shall be effective till the end of its life”. A reader approved years ago against 865–867 MHz does not become unlawful because the band moved; the wider allocation is the question for what you buy next.
Two caveats worth stating plainly. The 2 W figure is an interrogator limit on those four channels, not a blanket allowance across 865–868 MHz — the same Rules cover the band for non-RFID short-range uses at far lower power. And allocations are revised: confirm the current position with WPC before you commit a specification. Our BIS and WPC compliance guide works through what to ask a supplier for, and what BIS certification does and does not cover.
| UHFSingle worldwide Gen2 standard20x the range and speed of HFThe technology for item tagging | HF and LFMultiple competing standardsHF-based NFC for secure paymentUsed in immobilizers, ticketing, payment |
Passive, Active, and BAP RFID Systems
Active RFID Systems Shop Active RFID
In active RFID systems, tags have their own transmitter and power source. Usually, the power source is a battery. Active tags broadcast their own signal to transmit the information stored on their microchips.
Active RFID systems typically operate in the ultra-high frequency (UHF) band and offer a range of up to 100 m. In general, active tags are used on large objects, such as rail cars, big reusable containers, and other assets that need to be tracked over long distances.
There are two main types of active tags: transponders and beacons. Transponders are “woken up” when they receive a radio signal from a reader, and then power on and respond by transmitting a signal back. Because transponders do not actively radiate radio waves until they receive a reader signal, they conserve battery life.
Beacons are used in most real-time locating systems (RTLS), in order to track the precise location of an asset continuously. Unlike transponders, beacons are not powered on by the reader’s signal. Instead, they emit signals at pre-set intervals. Depending on the level of locating accuracy required, beacons can be set to emit signals every few seconds, or once a day. Each beacon’s signal is received by reader antennas that are positioned around the perimeter of the area being monitored, and communicates the tag’s ID information and position.
Passive RFID Systems Shop Passive RFID
In passive RFID systems, the reader and reader antenna send a radio signal to the tag. The RFID tag then uses the transmitted signal to power on, and reflect energy back to the reader.
Passive RFID systems can operate in the low frequency (LF), high frequency (HF) or ultra-high frequency (UHF) radio bands. As passive system ranges are limited by the power of the tag’s backscatter (the radio signal reflected from the tag back to the reader), they are typically under about 10 m across the passive family as a whole, with passive UHF at the top of that span — roughly 10–15 m with a fixed reader, as above. Because passive tags do not require a power source or transmitter, and only require a tag chip and antenna, they are cheaper, smaller, and easier to manufacture than active tags.
Passive tags can be packaged in many different ways, depending on the specific RFID application requirements. For instance, they may be mounted on a substrate, or sandwiched between an adhesive layer and a paper label to create smart RFID labels. Passive tags may also be embedded in a variety of devices or packages to make the tag resistant to extreme temperatures or harsh chemicals.
Passive RFID solutions are useful for many applications, and are commonly deployed to track goods in the supply chain, to inventory assets in the retail industry, to authenticate products such as pharmaceuticals, and to embed RFID capability in a variety of devices. Passive RFID can even be used in warehouses and distribution centers, in spite of its shorter range, by setting up readers at choke points to monitor asset movement.
Battery-Assisted Passive (BAP) Systems Shop BAP Systems
A Battery-Assisted Passive RFID tag is a type of passive tag which incorporates a crucial active tag feature. While most passive RFID tags use the energy from the RFID reader’s signal to power on the tag’s chip and backscatter to the reader, BAP tags use an integrated power source (usually a battery) to power on the chip, so all of the captured energy from the reader can be used for backscatter. Unlike transponders, BAP tags do not have their own transmitters.
| Active RFID | Passive RFID | Battery-Assisted Passive (BAP) | |
|---|---|---|---|
| Tag Power Source | Internal to tag | Energy transfer from the reader via RF | Tag uses internal power source to power on, and energy transferred from the reader via RF to backscatter |
| Tag Battery | Yes | No | Yes |
| Availability of Tag Power | Continuous | Only within field of reader | Only within field of reader |
| Required Signal Strength from Reader to Tag | Very Low | Very high (must power the tag) | Moderate (does not need to power tag, but must power backscatter) |
| Available Signal Strength from Tag to Reader | High | Very Low | Moderate |
| Communication Range | Long Range (100m or more) | Short range (up to 10m) | Moderate range (up to 100m) |
| Sensor Capability | Ability to continuously monitor and record sensor input | Ability to read and transfer sensor values only when tag is powered by reader | Ability to read and transfer sensor values only when tag receives RF signal from reader |
Credits :Impinj
Buying for a site outside India? See our global guide to RFID frequency by country and UHF bands worldwide.
Allocations are revised by regulators, and not only in India: a pending US petition to reconfigure the 902-928 MHz band is set out in our post on 900 MHz RFID spectrum vs India’s 865-868 band, along with why band-specific readers are not interchangeable.