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How to Encode an RFID Tag: Chipped RFID and Chipless RFID Encoding

  • Abhishek Shukla
  • Sep 19, 2023
  • RFID
How to Encode an RFID Tag: Chipped RFID and Chipless RFID Encoding

Chipped RFID tags are encoded using customized software and RFID readers, and RFID printers while chipless RFID readers are encoded using time-domain and frequency-domain encoding techniques.

As Radio Frequency Identification technology is getting traction and more and more businesses actively implement RFID in their inventory and supply chain, the demand for RFID printing and encoding services is bound to soar high. RFID tagging of items in various businesses such as retail, supply chain and logistics, manufacturing, healthcare, library management, etc. enabling advanced, throughout monitoring, identification, and tracking of items. It has led to increased accuracy and efficiency in stores and warehouses while customer experience has also improved in retail stores. 

 As an AIDC technology, RFID has become a successful replacement for barcodes that we often see on various products including FMCG, electronics home and furniture, toys, etc. Chipless RFID tags, with no microchip and simple fabrication, are extremely inexpensive and provide efficient identification and tracking of objects in comparison to barcodes. 

How to Encode an RFID Tag

The RFID technology employs an RFID tag, an RFID reader, and computer software to accurately identify and track objects. An RFID tag is fabricated using an antenna and a microchip (passive RFI D tags) while some other RFID tags come with a power source in the form of batteries (active RFID tags and battery-assisted passive RFID tags).

When you encode an RFID tag, the information is stored in various memory banks inside the microchip. The microchip also contains a transceiver which allows the tag to transmit and receive radio frequency signals. 

Before encoding an RFID tag, we must also know how the microchip memory is configured. There are various memory banks that contain distinct types of data. The TID memory bank in an RFID microchip contains a tag identifier, usually coming from tag manufacturers, and the EPC memory bank stores the unique electronic product code which helps in the identification of the item. It is read-only meaning it cannot be changed or modified. 

Apart from that the microchip can have a user memory bank and a reserve memory bank. The user memory bank stores added information about the product such as expiry date, manufacturing date, batch no. etc. while the reserve memory bank stores the access and kill passwords which are useful in preventing unauthorized overwrite/tempering and irrevocably deactivating the RFID tag, respectively. 

 Now that we know what kind of data can be used to write an RFID tag, let’s see how the encoding is performed. 

  • 1. RFID Tag Encoding using a Handheld RFID Reader
  • 2. RFID Tag Encoding using a Fixed RFID reader
  • 3. RFID Tag Encoding Using an RFID Printer

RFID Tag Encoding using a Handheld RFID Reader

Many RFID handheld readers are designed for RFID tag reading as well as tag encoding/writing purposes. You can use such RFID readers to remotely write an RFID tag from a distance. 

RFID handheld readers come with a preinstalled software system that supports tag reading and encoding. It is one of the simplest methods to encode a tag because the software interface is very easy to understand and you can customize the EPC (electronic product code) as per your need. 

RFID Tag Encoding using a Handheld RFID Reader is also cost-effective as you would not need an alternate encoding service provider for the same. To prevent overwriting or interference from other many RFID readers and tags in the vicinity, these readers also come with Anti-Collision and Dense Reader Mode. 

Since Handheld RFID readers come with a display, it becomes easier to observe the encoding process and rectify errors, if any.

RFID Tag Encoding using a Fixed RFID reader

Another inexpensive method to encode RFID tags is using a fixed RFID reader, an RFID module, and encoding software which is often custom-built. At EnCStore, we use a custom build tag reading and writing software where you can see the tags being encoded with the EPC. The software system also lets you see if any tag is not encoded or if there was an error with encoding.

RFID Tag Encoding Using an RFID Printer

RFID printers are generally used for printing RFID tags. Various kinds of RFID printers are available from Zebra, Honeywell, etc. that allow fast and quality printing using ribbons. These printers are suitable for commercial and industrial-scale RFID printers and encoding purposes. 

RFID printers can be programmed for customized encoding purposes. Zebra ZT411 printer can be set up to encode all kinds of tags, RFID labels, inlays, and hard tags.

While encoding, you must be aware that the EPC memory bank is at least 96 bits but most tags in the market today have more than 128 bits and a specific command must be given to the printer that you want to use not just 96 bits but more. 

While encoding through RFID printers is quite efficient and quick and can be done while printing the tags, setting up the printer is a bit tedious.

Once the printer is set up properly, printing and encoding is quite easily done. In an industrial setting where large-scale printing and encoding are required, RFID printers are the best choice. 

Encoding a Chipless RFID Tag

Encoding a Chipless RFID Tag is a different ballgame altogether. Since Chipless RFID tags do not contain a silicon microchip and are fabricated using reflector and resonator materials, the encoding is done using the properties of the material itself.

While encoding a Chipless RFID, the two most popular methods of encoding are used namely Time domain and Frequency domain encoding techniques. There are image-based and hybrid Chipless RFID tags as well (based on the encoding technique being used).

Time-domain Chipless RFID Tags and Encoding 

The encoding process in time-domain chipless RFID tags involves manipulating the time delay or time interval between different events or reflections within the tag. These events or reflections can be generated by various means, such as the interaction of the tag with radio frequency (RF) signals or the use of specific materials or structures within the tag.

In Chipless RFID tags, the time-domain encoding techniques can vary depending on the specific implementation. Some common techniques are as follows:

Time Delay Encoding

The time delay technique involves introducing intentional time delays between different events or reflections within the tag. Here, the specific pattern and duration of the time delays represent encoded data.

Time Interval Encoding

In this technique, the tag encodes data by manipulating the time intervals between events or reflections. The duration of the intervals and the sequence in which they occur convey the encoded information.

Pulse Position Modulation

Pulse Position Modulation uses the position of pulses within a time frame to encode data. Here, the presence or absence of pulses at specific time positions represents binary information.

Time-domain chipless RFID tags offer several advantages over traditional chip-based RFID tags. They are typically more cost-effective to produce since they do not require an IC chip, and they can be printed or fabricated using low-cost materials and manufacturing processes. Time-domain chipless RFID tags also exhibit a higher level of security, as they do not contain a permanent identifier like a chip-based tag. Instead, the encoded data is transient and can be changed or updated, enhancing privacy and anti-counterfeiting capabilities.

Frequency-Domain Chipless RFID Tags and Encoding

Frequency-domain chipless RFID tags are another type of chipless RFID technology that operates by encoding data in the frequency domain. These tags utilize various techniques to encode information by manipulating the frequency characteristics of the tag's response to RF signals.

The encoding process in frequency-domain chipless RFID tags involves designing the tag's structure or materials to create resonant frequencies or frequency notches at specific frequencies. These resonant frequencies or notches can be selectively activated or deactivated to represent encoded data.

The frequency-domain encoding techniques used in chipless RFID tags can vary depending on the specific implementation as follows:

Frequency Shift Encoding

Frequency shift encoding involves shifting the resonant frequency of specific resonators or structures within the tag to represent binary values. It is done by changing the physical dimensions or properties of the resonator materials used in the tag fabrication.

Frequency Notch Encoding

In this technique, the tag creates frequency notches or dips at specific frequencies by exploiting interference or resonance phenomena. The presence or absence of these notches at certain frequencies represents encoded data.

Frequency Modulation

In frequency modulation, the frequency of the tag's response can be modulated to represent binary information.

Frequency-domain chipless RFID tags offer advantages such as high data capacity and robustness. It can store a larger amount of data compared to a time-domain chipless RFID tag due to the higher number of frequency states that can be encoded. A Frequency-domain tag is also less affected by environmental factors such as noise or interference making it more reliable in challenging operating conditions such as warehouses and industries.

To conclude, encoding an RFID tag is a skilled task and should be done by skilled persons. There are various kinds of devices such as readers and printers that can be used for encoding purposes. Customized encoding software is also used while encoding a chipped RFID tag.

Encoding a Chipless RFID tag is also done via various encoding techniques including time domain and frequency domain, image domain, and hybrid encoding techniques. 


Disclaimer: The information presented here is for general information purposes only and true to best of our understanding. Users are requested to use any information as per their own understanding and knowledge. Before using any of the information, please refer to our Privacy Policy and Terms and Conditions.

  • Created on Sep 19, 2023

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