Every RFID system can be broken down by the frequency band in which it operates. Whether it is low, high or ultra-high frequency – there are many other categories of RFID systems as well. However, there are two major categories of RFID systems – active and passive, and we are explaining each of their types and frequencies below.
The frequency refers to the size of the radio that is used to communicate between each of the RFID system components. Hence the RFID systems are able to operate in low frequency (LF), high frequency (HF) and ultra-high frequency (UHF) bands. The radio waves are able to behave differently in each of these frequencies – and there are pros and cons of each frequency band.
On the off chance that a RFID system works at a lower recurrence, it has a shorter perused range and slower information read rate, yet expanded abilities for perusing close or on metal or fluid surfaces. On the off chance that a system works at a higher recurrence, it for the most part has speedier information exchange rates and more read extents than lower recurrence systems, however more affectability to radio wave obstruction brought on by fluids and metals in the earth.
The LF band covers frequencies from 30 KHz to 300 KHz. Regularly LF RFID systems work at 125 KHz, in spite of the fact that there are some that work at 134 KHz. This recurrence band gives a short read scope of 10 cm, and has slower perused speed than the higher frequencies, yet is not exceptionally delicate to radio wave impedance.
LF RFID applications incorporate access control and domesticated animals following.
Gauges for LF creature following systems are characterized in ISO 14223, and ISO/IEC 18000-2. The LF range is not viewed as a really worldwide application on account of slight contrasts in recurrence and power levels all through the world.
The HF band ranges from 3 to 30 MHz. Most HF RFID systems work at 13.56 MHz with read ranges between 10 cm and 1 m. HF systems experience moderate affectability to impedance.
HF RFID is ordinarily utilized for ticketing, installment, and information exchange applications.
There are a few HF RFID principles set up, for example, the ISO 15693 standard for following things, and the ECMA-340 and ISO/IEC 18092 gauges for Near Field Communication (NFC), a shortrange innovation that is regularly utilized for information trade between devices. Other HF principles incorporate the ISO/IEC 14443 An and ISO/IEC 14443 benchmarks for MIFARE innovation, which utilized as a part of keen cards and closeness cards, and the JIS X 6319-4 for FeliCa, which is a savvy card system usually utilized as a part of electronic cash cards.
The UHF recurrence band covers the reach from 300 MHz to 3 GHz. Systems consenting to the UHF Gen2 standard for RFID utilize the 860 to 960 MHz band. While there is some fluctuation in recurrence from area to locale, UHF Gen2 RFID systems in many nations work somewhere around 900 and 915 MHz.
The read scope of detached UHF systems can be the length of 12 m, and UHF RFID has a speedier information exchange rate than LF or HF. UHF RFID is the most touchy to impedance, however numerous UHF item producers have discovered methods for planning labels, antennas, and readers to keep execution high even in troublesome situations. Inactive UHF labels are simpler and less expensive to make than LF and HF labels.
UHF RFID is utilized as a part of a wide assortment of applications, extending from retail stock administration, to pharmaceutical hostile to forging, to wireless device design. The heft of new RFID tasks are utilizing UHF contradicted to LF or HF, making UHF the quickest developing section of the RFID market.
The UHF recurrence band is managed by a solitary worldwide standard called the ECPglobal Gen2 (ISO 18000-6C) UHF standard.
- Operating on the worldwide Gen2 standard
- 20x faster and with better range than HF
- The price of labels was 5¢–15¢ in 2012
- Ideally used for item tagging
HF and LF
- Operates on multiple competing standards
- Leverages a HF-based NFC made for secure payment
- The price of labels, cards and inlays cost 50¢–$2
- Used in many industries from immobilizing to ticketing and payment
Active, Passive and BAP RFID Systems
Active RFID Systems
In active RFID systems, every tag has its own particular transmitter and power source. In most of the cases, the power source is a battery. Active tags show their own sign to transmit the data put away on their microchips.
Active RFID systems regularly work in the ultra-high recurrence (UHF) band and offer a scope of up to 100 m. By and large, active tags are utilized on expansive items, for example, rail autos, enormous reusable holders, and different resources that should be followed over long separations.
There are two fundamental sorts of active tags: transponders and reference points. Transponders are “woken up” when they get a radio sign from a reader, and after that power on and react by transmitting a sign back. Since transponders don’t effectively emanate radio waves until they get a reader signal, they moderate battery life.
Reference points are utilized as a part of most ongoing finding systems (RTLS), so as to track the exact area of an advantage persistently. Not at all like transponders, reference points are not fueled on by the reader’s sign. Rather, they discharge signals at pre-set interims. Contingent upon the level of finding exactness required, reference points can be set to transmit flags at regular intervals, or once per day. Every reference point’s sign is gotten by reader antennas that are situated around the border of the region being checked, and imparts the tag’s ID data and position.
Passive RFID Systems
In passive RFID systems, the reader and reader antenna send a radio sign to the tag. The RFID tag then uses the transmitted sign to control on, and reflect vitality back to the reader.
Aloof RFID systems can work in the low recurrence (LF), high recurrence (HF) or ultra-high recurrence (UHF) radio groups. As passive system extents are restricted by the power of the tag’s backscatter (the radio sign reflected from the tag back to the reader), they are normally under 10 m. Since latent tags don’t require a power source or transmitter, and just require a tag chip and antenna, they are less expensive, littler, and simpler to produce than active tags.
Aloof tags can be bundled in a wide range of routes, contingent upon the particular RFID application necessities. Case in point, they might be mounted on a substrate, or sandwiched between a cement layer and a paper mark to make keen RFID names. Latent tags may likewise be implanted in an assortment of devices or bundles to make the tag impervious to great temperatures or cruel chemicals.
Aloof RFID arrangements are valuable for some applications, and are usually sent to track merchandise in the store network, to stock resources in the retail business, to validate items, for example, pharmaceuticals, and to insert RFID capacity in an assortment of devices. Detached RFID can even be utilized as a part of stockrooms and dispersion focuses, notwithstanding its shorter extent, by setting up readers at stifle focuses to screen resource development.
Battery-Assisted Passive (BAP) Systems
A Battery-Assisted Passive RFID tag is a kind of inactive tag that joins a urgent active tag highlight. While most latent RFID tags utilize the vitality from the UHF RFID reader’s sign to control on the tag’s chip and backscatter to the reader, BAP tags utilize a coordinated power source (more often than not a battery) to control on the chip, so the greater part of the caught vitality from the reader can be utilized for backscatter. Not at all like transponders, BAP tags do not consist of 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|
|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|