Below are the some of the most common terms used when reading about and discussing RFID applications. This list is always being updated with new terms and ways to learn more about how these concepts, devices, and principles apply to your RFID application.
If you are new to RFID, don't forget to start with our Beginner's Guide to RFID that slowly introduces RFID terminology in way that you can understand.
A tag's Access Code/Access Passcode is a password that can be used to lock and unlock a tag's reading and writing capabilities and is stored in the Reserved Memory Bank. Read more about how Access Codes apply to your RFID application.
A security technique that allows a company to control who or what enters a place or an area. This can be achieved by using RFID technology to allow or restrict access to buildings, rooms, areas, lots, roads, garages, and other contained areas. Read more about Access Control Applications.
“Active” means that the RFID transponder/tag has its own power source. It broadcasts its signal and typically has a longer read range than passive transponders/tags. Read more about how Active RFID Systems apply to your RFID application.
An RFID tag that has its own power source that sends signals to the readers and antennas. Usually has a battery life of 5-10 years.
An RFID reader that can read tags operating at different frequencies or use multiple means of communication between the tags and readers.
Air Interface Protocol
A set of rules governing how tags and readers communicate.
An RFID Antenna is a device that connects to an RFID Reader via an Antenna Cable. An RFID Antenna takes the AC current sent by the RFID Reader through the Cable, builds an electromagnetic field, and then releases the energy as Electromagnetic waves in the direction dictated by the Antenna's radiation pattern. An RFID Antenna also collects modulated RF energy that is sent back from RFID tags in the read area. Read more about how RFID Antennas apply to your RFID application.
The component that allows the transponder/tag to send and receive data. The tag antenna connects to the tag's IC and powers the IC with the RF energy it collects and takes the IC's modulated data and sends it back out into the read area. Read more about how RFID Tag Antennas apply to your RFID application.
An Antenna Cable, also called a Coax Cable or Coaxial Cable, is an electrical cable surrounded by a layer of insulation that helps contain the conducted energy within the Cable. An Antenna Cable is used to connect an RFID Reader and RFID Antenna in an RFID System. Read more about how RFID Antenna Cables apply to your RFID application.
The antenna’s ability to direct scattered radio frequency into a more direct and effective plane. Antenna gain increases the signal, which enables antennas with higher gain to read tags from a greater distance. Read more about how Antenna Gain applies to your RFID application.
Describes the various methods of preventing interference between the radio waves of multiple devices. Ideal feature for reading more than one tag in a crowded read zone. Read more about how Anti-Collision applies to your RFID application.
Application Programming Interface (API)
Application Programming Interface, called API is the interface implemented by an application that allows communication with other applications. API is set in a certain programming language that explains how data will be remembered. Read more about how APIs apply to your RFID application.
ASCII, or American Standard Code for Information Interchange, is an encoding method that uses 128 specific characters, each represented by two strings of four bits. ASCII can represent the entire alphabet (lower case and upper case), numbers 0-9, as well as some special characters, such as asterisks, question marks, and parenthesis. Read more about how ASCII Code applies to your RFID application.
An ASIC is also known as an application specific integrated circuit (IC) and is basically an integrated circuit that was manufactured for or customized for a specific application. Customization usually includes adhering to a unique set of standards for a specific application industry.
One of the most common applications for RFID. Companies can quickly locate high-value assets and/or transport containers by placing RFID transponders/tags on or in them. By implementing an Asset Tracking system, companies can increase the usage of individual assets, track and maintain asset usage history, strategically plan future asset usage, and reduce costs associated with losing and replacing lost assets. Read more about Asset Tracking applications.
Attenuation is the reduction of amplitude of a signal, electric current, or other oscillation. Attenuation is typically discussed when referring to RFID antenna cables and the RF energy that can be lost within the cable between the RFID Reader and RFID Antenna. Read more about how Attenuation applies to your RFID application.
Authentication is the act or process of proving that something is genuine, true, or valid. Authentication of a product or item can be done using RFID technology, making RFID Authentication an RFID application. Read more about Authentication applications.
A method of communication between passive tags and readers. RFID tags using backscatter technology receive radio waves from a reader and reflect those waves back to a reader, usually at the same carrier frequency. The reflected signal is then modulated to transmit data. Read more about how Backscatter applies to your RFID application.
A Barcode is a number that is coded in the form of varying patterned lines that is printed on a product or item and read by machines like scanners, phones, and other devices. The lines are read, decoded, and the code is then used to identify the product or item it has been printed on.
A device, also known as an optical scanner, that uses a light source (typically a laser) to scan and decode barcodes.
See Battery Assisted Passive Tags.
Battery-Assisted Passive Tags (BAP Tags)
Battery-Assisted Passive Tags, also called BAP tags, Semi-Passive Tags, or Semi-Active Tags, Battery-Assisted Passive (BAP) tags are essentially passive RFID tags with an internal battery. Because these tags wait for a signal from an RFID reader before they respond, they function similarly to active transponder tags. Read more about how Battery-Assisted Passive Tags apply to your RFID application.
See BLE Beacons.
Binary Code is a coding system using the binary digits 0 and 1 to represent a letter, digit, or other character in a computer or other electronic device. Read more about how Binary Code applies to your RFID application.
Bistatic refers to a system that uses two separate devices to communicate – one to transmit a signal, and one to receive a signal. Most RFID systems are Monostatic, which means they use one RFID Antenna to both transmit and receive a signal. However, bistatic systems can be created that use one RFID antenna to transmit signals and a different RFID antenna to receive signals. Read more about how BIstatic Systems apply to your RFID application.
Bits are basic units of information that can either be a "0" or a "1". Strings of bits can be converted into hexadecimal coding or ASCII coding depending on the exact placements of "0" and "1". Read more about how Bits apply to your RFID application.
A BLE Beacon is a radio transmitter that continually broadcasts specific data via Bluetooth low-energy signals to BLE devices that can receive the data within a specific area. Read more about how BLE Beacons apply to your RFID application.
See Antenna Cable.
Cable Bend Radius
Cable Bend Radius is the smallest allowed radius the cable can be bent around in order to not cause stress on the cable. If the cable is bent further than the appropriate bend radius, it can damage and degrade its performance and generate interference in data transmission.
Central Processing Unit (CPU)
The “brains” of the computer. The CPU controls all other parts of the computer and is responsible for executing operations.
See Integrated Circuit.
See Integrated Circuit.
A circular-polarized antenna sends its radio waves in a circular pattern to make it easier to read tags in which the direction cannot be controlled. The circular pattern emitted from the antenna increases the wave’s chance of reaching the antenna; however, their read range is shorter than that of a linear-polarized antenna. Read more about how Circular-Polarized Antennas apply to your RFID application.
Commissioning generally refers to writing or programming an RFID tag with a specific EPC number or Data.
Two RFID systems must use the same protocols, frequencies, and voltage levels to be considered compatible. Being compatible allows two systems to operate together within the same overall application.
Constructive Interference is when two electromagnetic waves sent out by the RF antenna intersect at the same phase, which strengthens the wavelength. The strengthened wavelength makes it possible to read well outside of normal read ranges thanks to constructive interference. Read more about how Constructive Interference applies to your RFID application.
The ability of a microchip to maintain the information stored in read-only memory. RFID tags can usually retain data for 10 years or more depending on temperature, humidity, and other factors.
Defines the gain of an antenna relative to an isotropic antenna. Read more about how dBi applies to your RFID application.
dBm is a unit of measurement to indicate that a power level is expressed in decibels (dB) with reference to one milliwatt (mW) and is commonly used to express RFID Reader Transmit Power. Read more about how dBm applies to your RFID application.
dBw is a unit of measurement of the strength of a signal expressed in decibels relative to one Watt.
Deactivation generally refers to making the RFID tag unusable, which can be done via a Kill Command or physically destroying the tag. Deactivation can also be done in a system or database to indicate that the tag is no longer in use or no longer available. Usually system deactivated tags can still be read, but are no longer registered in a company’s database or associated with any relevant information.
An RFID Tag that can no longer be read.
A unit of measurement that represents the difference in the intensity of an emitted signal or level of power when 0 dB is used as the reference. dB is used to measure antenna gain, cable losses, and reader power output.
A way of scrambling data in which only intended users are able to unscramble and read the data. Used as a security measure to protect the information stored on a transponder’s microchip and to prevent communications between the tag and reader from being intercepted. Read more about how Encryption applies to your RFID application.
Electronic Product Code
The Electronic Product Code (EPC) uses a series of unique digits to universally identify an item’s manufacturer, product category, and the individual item.
EPC Gen 2
The standard air-interface protocol approved by EPC global for the second generation of EPC technologies. Read more about how EPC Gen2 applies to your RFID application.
EPC Memory Bank
The Electronic Product Code (EPC) Memory Bank on standard Gen2 RFID Tags is one of four memory banks, and it holds the EPC number, also known as the Electronic Product Code. The EPC number can be reprogrammed by an RFID Reader and usually varies in length from 96 bits to 496 bits; however, the most common EPC lengths are 96 and 128 bits. Read more about how EPC Memory Banks apply to your RFID application.
A non-profit organization set up by the Uniform Code Council and EAN International to commercialize EPC technology. Read more about EPCglobal.
A Faraday Cage or Shield is an enclosure used specifically to block electromagnetic fields and RF energy from entering or exiting a specific area. In RFID applications, Faraday Cages can be used to contain RF energy and create a custom read zone or block RF energy.
An RFID tag is considered to be in the “far-field” if it is outside of one full wavelength of the reader. Passive RFID systems that rely on far-field communication have a longer read range than those using near-field communication. Read more about how Far-Field Communication applies to your application.
A Fixed RFID Reader is an high-performance RFID reader that is typically affixed to a wall, shelf, or other fixed position and does not need to be mobile. Read more about how Fixed Readers affect an RFID system.
The various types of packaging a transponder can be put in, such as thermal transfer labels, plastic cards, key fobs, etc. Read more about how Form Factor applies to your RFID application.
The rate at which cycles of waves occur in a single second. Frequency is measured in Hertz and 1 Hz is equal to one wave cycle per second. There are several levels of frequencies in RFID tags that are beneficial for different applications. The four frequencies that RFID Tags use are low (135 kHz), high (13.56 MHz), ultra-high (860 – 960 MHz), and microwave (2.4 GHz). Read more about how Frequency applies to your RFID application.
Frequency hopping is a technique that RFID Readers use to prevent reader collisions that allow them to ‘hop’ to different frequencies within a set range. Readers stay and transmit on one frequency (also called a channel) for no more than 0.4 seconds and then hop to another frequency to avoid transmitting on the same frequency as another reader – which would cause a collision. Read more about how Frequency Hopping applies to your RFID application.
See EPC gen 2
Gen2v2 is the second version of the Gen2 protocol, set by GS1 and ratified in 2015. Read more about Gen2 v2.
GIS Software, or Geographic Information System Software, is software that ‘is designed to store retrieve, manage, display, and analyze all types of geographic and spatial data.’
Global Positioning System (GPS)
A satellite-based radio navigation system owned by the United States Government that can send and receive location data. Read more about GPS technology versus Active RFID.
A GPIO device is a device that plugs into an RFID Reader's GPIO port and performs actions based upon triggers sent by the RFID reader. GPIO devices provide additional functionality like audio or visual signals to RFID applications. Read more about how GPIO devices apply to your RFID application.
Hex, or hexadecimal coding (also called base 16), is a coding method that utilizes only 16 types of characters - letters A-F and numbers 0-9. Each hexadecimal character represents a string of four bits. Read more about how Hexadecimal coding applies to your RFID application.
High-frequency is a frequency measurement that is between 3 MHz and 30 MHz. High-frequency tags can transmit data faster than low-frequency tags, but they use more power than low-frequency tags. For RFID, the typical operating frequency is 13.56 MHz. Read more about High-Frequency RFID and the RFID applications that use it.
See BLE Beacons.
See Integrated Circuit.
In an RFID system that uses inductive coupling, the coil on the reader antenna and the coil on the tag antenna form a magnetic field. The tag draws energy from the field and that energy is used by the microchip to change the electrical load on the tag antenna. The reader antenna picks up the electrical changes and translates them into a unique serial number. Read more about how Inductive Coupling applies to your RFID application.
Composed of just an Integrated Circuit and an aluminum, copper, or silver antenna. They can be classified as “wet” or “dry” depending on if the inlay has an adhesive liner or not. Inlays can also be converted into smart labels. Read more about how RFID Inlays are different from RFID Labels.
Ports on an RFID reader that allow external devices to be connected for the unique needs of a user’s application. Read more about how Input/Output Ports affect your RFID system.
Integrated Circuit (IC)
An Integrated circuit is a microchip/chip that is a small wafer made of silicon that can hold transistors, resistors, and capacitors, that store usage data and algorithms. In an RFID tag, the Integrated Circuit holds four memory banks and performance information like communication modes and frequency protocols. Read more about how Integrated Circuits (ICs) affects your RFID application.
An Interrogation zone is very similar to a read zone and is an area of space that an RFID reader can successfully read an RFID tag.
Identical in all directions. An antenna that releases equal amounts of energy in every direction is an isotropic antenna. Read more about how Isotropic Antennas apply to your application.
Also called Kill Code, when sent to a tag, a kill command will deactivate the tag and will make any data on the tag unreadable. Read more about how Kill Commands apply to your RFID application.
License Plate Tag
A license plate tag is an RFID tag that contains specific information for identifying the automobile or machine to which it is attached. Read more about how License Plate Tags could affect your RFID application.
An antenna that sends its radio waves out in a specific alignment. Linear polarization increases read distance and allows better penetration through dense materials. Tags must be aligned with the reader antenna in order to be read. Read more about how Linear-Polarized Antennas apply to your RFID application.
Locking an RFID Tag is essentially locking the tag’s memory from being read. Locking a Gen2 RFID Tag can be accomplished by using the Access Password in the Reserved Memory Bank. Read more about how Locking RFID Tags could affect your RFID application.
Low-frequency is a frequency measurement that is between 30 kHz and 300 kHz. Low-frequency tags are not as prone to interference as ultra-high frequency tags. However, data is sent at a slower rate, and they must be read from three feet or closer. Read more about Low-Frequency RFID and the RFID applications that use it.
Memory is the total data that can be stored in a specific microchip. A microchip can hold between 64 bits and 32 kilobytes of memory. On an RFID tag, there are typically four memory banks - EPC, User, Reserved, and TID. Read more about Memory and how it applies to your RFID application.
Groups of Memory that are partitioned separately according to Gen2 protocols – four banks are available on Gen2 RFID tags, EPC, Reserved, User, and TID. Read more about Memory Banks and how they applies to your RFID application.
A Memory Block is essentially a grouping of memory bits in a tag’s memory bank that typically can be operated on independently from other banks.
A Microcontroller is a small computer on a single integrated circuit chip that contains CPU’s, memory, and input/output peripherals.
Middleware is a layer of software that is created to connect two other software pieces – typically connecting two software programs or a software program and a device’s firmware. Middleware allows communication and data flow between programs so that each component in a system doesn’t have to be managed separately. Read more about how Middleware can impact your RFID application.
A Mobile Computer is a handheld device that is small, lightweight, and portable. Mobile Computers have operating systems, which mean that they have similar capabilities to a PC, with the addition of the ability to scan barcodes and capture data.
The various methods of changing the radio waves between a reader and an RFID tag to enable the transmission of information. Read more about how Modulation applies to your RFID application.
Monostatic refers to any system that uses one device to communicate – both to transmit and receive message. A Monostatic RFID system is a system that uses one antenna to both transmit and receive tag data. Monostatic RFID systems are the most common type of RFID system. Read more about how Monostatic Systems apply to your RFID application.
In RFID systems, a multiplexer is a device that allows an RFID reader to connect to more RFID antennas than possible on it’s own. Multiplexers allow for readers to double or triple the number of antennas per reader, which cuts costs and needed space for RFID applications.
Generally, passive UHF RFID antennas have two segments broken up by how they communicate with tags, the near-field communication portion that uses magnetic coupling and the far-field communication portion that can communicate via backscatter. Near-Field RFID Antennas are antennas that only have, and use near-field coupling to communicate with RFID tags up to one wavelength away (a few inches). Read more about how Near-Field Antennas or about Near-Field Antenna Systems and how they could affect your RFID application.
Near-field communication is the term used to describe the communication between an RFID tag and RFID reader within one wavelength (a few inches). Within the short vicinity, the tag uses magnetic/inductive coupling in order to communicate and not backscatter, like in Far-Field Communication. This type of communication and coupling is most often used with NFC/HF RFID tags, but can still be used in UHF tags within a close range. Read more about different aspects of Near-Field Communication Tags (13.56 MHz) or Near-Field Communication Systems (860 - 960 MHz) and how it could apply to your system.
NFC RFID Tags
NFC Tags, or Near-Field Communication Tags operate within the HF Frequency on a single frequency of 13.56 MHz. NFC tags are incredibly standardized and operate via ISO 14443 A and B, making them easily adoptable, globally. NFC tags use Near-Field communication (magnetic coupling) to send and receive data at short distances - on a few centimeters or inches. Read more about NFC RFID and popular applications.
Unwanted electrical signals or electromagnetic energy found in the immediate surrounding of operating RFID equipment.
A long-term form of storage that remains after the power to a system is turned off.
The area in a reader’s field that does not pick up radio waves. Read more about how Null Spots can affect your RFID application.
The location of a tag antenna position relative to a reader antenna. Linear-polarized antennas need to be aligned with the tag antenna for the tag to be read. If the tag’s alignment is not oriented correctly, the tag antenna will only receive a fraction of the energy. Read more about how Tag Orientation can affect your RFID application.
An RFID passive tag does not have an internal battery; therefore, it does not have an individual power source or transmitter. Radio waves sent from the reader to the chip’s antenna are converted into energy to power the microchip. Read more about how Passive Tags apply to your RFID application.
The ability of radio frequencies to go through non-metallic materials.
Permalock is a feature available on RFID tags, such as some Monza R6 tags, which permanently locks a memory bank so that the data on the bank cannot be changed. Read more about how Permalocking can affect your RFID application.
Printer (RFID Printer)
RFID Printers are devices that simultaneously print and encode information on RFID inlays or labels. These devices are the only way to print on labels, and they also save time by automating the manual process of encoding each tag. RFID Printers have embedded RFID Reader Modules that allow them to read and write RFID inlays. Read more about how RFID Printers can affect your RFID application.
A set of rules that regulate the communication between RFID systems. Read more about how Protocols can affect your RFID application.
Also called Q-Protocol, or adaptive Q Algorithm, the Q Algorithm is the most commonly used Anti-Collision protocol for Class 1 Gen2 UHF RFID Readers and Tags. It is a derivative of one of the main algorithms, Slotted Aloha. The Q-Algorithm is used during an inventory count, the interrogator (reader) breaks up the inventory into rounds (also called frames) and then asks the tags to pick a number between a certain set, 0-15 for example. The interrogator then starts to count down from the highest number of the set and each number it counts is considered a ‘slot’. The tags, meanwhile, select a random 16-bit number and use the last digit(s) as its Q-value or number between 0-15. When the tag hears the reader respond with its selected random number or Q-value, it responds with its 16-bit random number. Read more about how the Q Algorithm applies to your RFID application.
Radio Frequency Identification (RFID)
Describes the various methods of using radio waves to identify unique objects. Typically, this interaction happens when a reader communicates with a transponder to retrieve information stored on its microchip. Read more about RFID and how it works.
Random Access Memory (RAM)
A type of memory used to temporarily store data on a device. When the device’s power is cut off, all data stored in the RAM is cleared.
The percentage of tags that are successfully picked up by a reader in an RFID system. If 98 out of 100 tags are read in the operating environment, the read accuracy is 98 percent.
An RFID reader is the brain of the RFID system and is necessary for any system to function. Readers, also called interrogators, are devices that transmit and receive radio waves in order to communicate with RFID tags. Read more about RFID Readers and how they affect an RFID system.
Reader Collision is when two readers in the same read area on the same frequency interfere with each other’s signals. Reader Collisions can be mitigated by using Dense Reader Mode and Frequency Hopping and RF shielding. Read more about how Reader Collision can affect your RFID application.
Data stored on a RFID tag’s microchip that cannot be altered without reprogramming the microchip.
Read Range describes how far away a reader can successfully communicate with a tag. Active tags and passive tags have different read ranges. Because active tags have a battery, their read range is longer than passive tags. The read range of a passive tag is based on frequency, reader output power, antenna type, and the way the tag powers up. Read more about how Read Range can affect your RFID application.
The number of times a specific tag can be read in a period of time. Read rate can also represent the number of tags that can be read in a specific time period and how quickly data is read.
Read Sensitivity is a value determined and assigned to RFID tags by the manufacturer during testing that quantifies the lowest amount, or minimum amount of power required by the RFID reader for a successful tag read.
Data stored on an RFID tag’s microchip that can be rewritten as needed.
The Reserved Memory Bank stores the kill password and the access password (each are 32 bits). Read more about how the Reserved Memory Bank affects your RFID application.
See Radio Frequency Identification.
See Antenna (RFID Antenna).
See Reader (RFID Reader).
See Printer (RFID Printer).
See Tag (RFID Tag).
RSSI (Received Signal Strength Indicator)
RSSI, or Received Signal Strength Indicator, is a measurement of the power received from the returned signal from an RFID tag when interrogated by a reader. Read more about how RSSI can affect your RFID application.
A method that an RFID reader uses to be able to identify the unique identification number on a specific tag and distinguish it from the other tags in the same area.
The act of reading an RFID tag on someone without their knowledge or consent. Also called Eavesdropping, read more about Eavesdropping and how it could affect your RFID system.
Slotted Aloha is an Anti-Collision protocol that reduces the number of collisions from happening that result from two tags sending data to the same reader at the same time. With a true Slotted Aloha protocol, RFID tags can answer at the beginning of a randomly selected time slot to prevent answering at the same exact time. Most Class 1 Gen2 UHF Tags and Readers use the Q algorithm, based on Slotted Aloha as their Anti-Collision protocol. Read more about Slotted Aloha and how it could affect your RFID application.
Timing readers or reader antennas in the same operating environment to avoid interference.
Tag (RFID Tag)
An RFID tag is the microchip/antenna combination that receives signals from and then returns signals to an RFID reader. With a unique encrypted serial number, an RFID tag can communicate specific information about the item that it is applied to. Tags can be active, passive, or semi-passive and can come in many shapes and sizes to fit the application.
See Antenna (Tag).
TID Memory (Tag Identifier)
The TID Memory Bank is part of Gen2 UHF RFID tags and it stands for "Tag Identifier". TID numbers are usually 32 -80 bits in length, contain the chipset’s type and manufacturer, and are a read-only memory bank. Read more about TID Memory Banks and how they can affect your RFID application.
A device with the ability to send and receive radio waves.
Transponder is another name for an RFID tag. Transponders receive signals from and then send signals to an RFID reader.
See Ultra-High Frequency, below.
Ultra-High Frequency (UHF)
A frequency measurement that between 300 MHz and 3 GHz. Ultra-high frequency tags can transmit information farther and faster than high and low-frequency tags. However, their electrical waves have a difficult time passing through items with a high concentration of water.
Ulta-WideBand is a for of Radio Frequency communication that uses low-energy, very high frequency range (3.1 to 10.6 GHz), short transmissions to communicate. It is similar to Wi-Fi and Bluetooth in that it its main purpose is location discovery and device communication, but it is more accurate and uses less power than the other methods.
Unique Identifier (UID)
A unique encoded number that identifies the RFID tag. Also called TID.
Universal Product Code
The 12-digit data structure used in UCC barcodes.
The User Memory Bank is the second writable memory bank for user-defined data on Gen 2 RFID Tags. The User Memory Bank is typically used to store more information if the EPC Memory Bank runs out of space. Not all UHF RFID tags have User Memory Banks, and some have extended User Memory Banks. Read more about how the User Memory Bank can affect your RFID application.
See Ultra-WideBand (UWB), above.
WORM (Write Once, Read Many)
A tag that can only be written to one time, but can be read repeatedly.
Describes how quickly information is transferred to a tag, stored into the tag’s memory, and confirmed to be correct.
Read Sensitivity is a value determined and assigned to RFID tags by the manufacturer during testing that quantifies the lowest amount, or minimum amount of power required by the RFID reader for a successful tag read.