What are the components making up an RFID tag

What’s in an RFID tag?


RFID (Radio Frequency Identification) technology is a critical tool in the tracking and management of all kinds of assets and inventory to increase the visibility of these valuable items.


RFID inventory solutions in supply chain management help keep track of valuable stock and inventory in fast-moving supply chains to item, carton or pallet level, maintaining a real-time, accurate stock count at every stage from point of manufacture to point of sale. 


RFID asset tracking solutions help keep track of valuable business assets including vehicles, equipment, tools and technology in offices, warehouses, yards and work sites to improve operational efficiency, reduce losses and avoid expensive replacement costs. 


RFID tags are at the heart of RFID solutions


RFID tags are one of a handful of important components that make up RFID solutions. They can be affixed to a range of objects including assets, inventory, vehicles and even people as part of a customised RFID solution. RFID tags come in a variety of shapes, sizes and capabilities, but common to them all is the ability to store information and communicate data such as movement and location back to a central database.


We’ll take a look in detail at the physical components that make up an RFID tag, but first we’ll outline how RFID tags fit into an overall RFID solution.


RFID technology uses electromagnetic fields to automatically identify and track RFID tags attached to items (small to large), objects and people. 


RFID readers are used to ‘read’ tags from a distance, often with the simple wave of a hand in a packed storeroom full of tagged products using a handheld reader or App-enabled smartphone. Another type of fixed RFID reader (or station) can be strategically located in say a warehouse or workplace to track the movement of items, vehicles and people in and out.


All the information fed from tags to readers is then relayed to a central location where custom RFID software (such as RAMP’s Loca.fi need link to Loca.fi page?) stores and analyses a huge amount of data to identify the precise location of valuable items in real-time, as well as providing useful insights to help make more informed business decisions. 


RFID tag components and construction


RFID tags are also known as ‘smart’ tags because they include an integrated or electronic circuit, or chip. Like all technology, tags are getting smaller and cheaper as technology improves. Even still, RFID tags contain some very sophisticated technology that separates them from the humble barcode, their direct predecessor. 


It’s worth noting that there are two kinds of RFID tags – passive and active. The key difference between passive and active tags is that the latter has a battery to provide stand-alone power, adding a component (along with size and weight) to the tag. This article gives a good overview of the difference between passive and active tags. Passive tags are far more common and they are the focus of this detailed look at their components and construction.


Tags are designed and made for many different applications and are available in a wide range of sizes, shapes and strengths. Customised tags can be specified and made for particular applications, but this is a very expensive exercise, compared to buying tags off-the-shelf. 


RFID tags are made of three different components – an RFID chip (an integrated circuit), an antenna and a substrate (to which the other components are attached). Typically, RFID chips are made by semiconductor manufacturers, while antennae are made by the tag manufacturer. 


RFID chip: Also called an electronic circuit or microchip, the chip is literally the brain of an RFID tag. It has a logic unit that makes decisions and provides memory for data storage. Each chip can contain up to 50 thousand transistors. 


The chip needs power to operate, and in the case of passive tags, this power is derived from the radio energy provided by the RFID reader (or interrogator). The type of memory used in RFID tags does not require continuous power to store data, which can be retained for a number of years with no power. Advances in technology mean that these chips can be as small as a grain of sand.


Antenna: This is the largest part of the tag and is connected to the chip. The antenna receives signals from the RFID reader or interrogator, and in the case of passive tags, it reflects the received signal back while collecting power from the radio waves and supplying it to the chip. 


Antennae are generally made of thin metal strips of copper, aluminium or silver, and they come in a variety of sizes and shapes designed to operate at a particular frequency. Antennae are applied to the tag substrate using methods including copper etching, foil stamping and screen printing. 


Substrate: The substrate holds all the other tag components together. First, the antenna is deposited or printed on the substrate, then the chip is attached to the antenna. Passive tags typically use flexible material such as thin plastic with a thickness of 100 to 200 nanometres (a nanometre is a billionth of a metre). 


One side of the substrate is usually coated with an adhesive material to attach the tag to an object. The substrate material needs to be able to withstand a wide range of environmental conditions including heat, moisture, vibration, chemicals, sunlights, abrasion, impact and corrosion. 


Before you choose an RFID tag, choose Australia’s leading RFID specialists


RFID tags are an important part of an integrated RFID asset tracking technology solution. The right choice of tags, combined with RFID readers and software, helps create a powerful RFID solution to increase the visibility of valuable assets, save time, reduce costs and increase the bottom line. 


For a customised RFID technology solution talk to RAMP, Australia’s leading RFID specialist. We’ve been working with Australian businesses for over a decade to design and implement RFID solutions for supply chain, inventory and vehicle tracking, retail and a range of other applications across many industries. 


RAMP can help you automate and streamline processes to improve efficiency, minimise losses and increase visibility with our locally-based consultants, engineers and software developers.