RFID tags: How to store data? Why can it be repeatedly erased?

In today's rapidly developing technology, ultra-high frequency RFID (Radio Frequency Identification) electronic tags are gradually entering our lives and widely used in many fields such as logistics, retail, and healthcare. So, how do ultra-high frequency RFID electronic tags store data? Can these data be repeatedly erased?

01

What is ultra-high frequency RFID technology?

UHF RFID technology refers to radio frequency identification systems operating at frequencies between 300MHz and 3GHz, with the most common frequency range being 860-960MHz. Compared with low-frequency (LF) and high-frequency (HF) RFID, ultra-high frequency RFID has significant advantages such as long reading distance (up to 10 meters or more), fast reading speed (able to read hundreds of tags simultaneously), and large data capacity. Therefore, it has been widely used in logistics management, retail industry, asset management, intelligent manufacturing and other fields.

The ultra-high frequency RFID system consists of three parts: a reader, an antenna, and an electronic tag. Among them, electronic tags are the carrier of data, and their storage capacity and data manageability directly determine the application value of the entire system.

Data storage structure of ultra-high frequency RFID tags

1. Physical storage composition of tags

The storage unit of ultra-high frequency RFID tags is usually composed of integrated circuit chips and antennas. The chip contains:

① Analog front-end: responsible for receiving and transmitting RF signals

② Digital Control Unit: Processing Instructions and Logic Control

③ Memory: Used for storing data, usually divided into multiple storage areas

2. Standardized storage partitioning

Label storage is typically divided into four main areas:

① Reserved memory: 32-bit, storing access and deactivation passwords for tags

② EPC memory: variable length (usually 96-496 bits), storing electronic product codes

③ TID memory: 64 bit or more, storing the unique identifier of the tag, written by the chip manufacturer

④ User memory: variable capacity (from 0 to thousands of bits) for users to freely use

3. Storage capacity range

The storage capacity of different models of ultra-high frequency RFID tags varies greatly:

① Low end label: 96-128-bit EPC storage, no user memory

② Mid end label: 96-496 bit EPC storage, 32-512 bit user storage

③ High end tags: 496 bit or more EPC storage, 512 bit to 8K bit user memory

03

Storage Principles

The process of storing data in ultra-high frequency RFID electronic tags is like a "wireless conversation" between readers and tags.

When the reader needs to write data to the electronic tag, it will first emit a specific frequency RF signal through the antenna, which is like a "call" from the reader to the tag. After the antenna of the electronic tag receives this RF signal, it will convert it into electrical energy to provide the energy required for the tag chip to work (for passive tags, this is the only way to obtain energy).

At the same time, the tag chip will modulate the signal emitted by the reader/writer and load the data to be written onto the reflected wave

Then, the reflected signal with data is sent back to the reader/writer through the tag antenna. After receiving the reflected signal, the reader/writer will perform a series of processing such as demodulation and decoding.

Finally, write the data accurately and without error into the corresponding storage area of the tag chip.

During this process, data is stored in binary form. Various types of information commonly found in our daily lives, such as text, numbers, images, etc., are converted into binary codes consisting of 0s and 1s in electronic tags. Just as we use different letter combinations to express different meanings, electronic tags store various information through different arrangements and combinations of 0s and 1s.

04

Data eraser: Can it be repeatedly erased

A significant advantage of ultra-high frequency RFID electronic tags is that their data can usually be repeatedly erased and written, which is like a notebook that can be used repeatedly, very convenient and flexible.

The number of data erasures for ultra-high frequency RFID electronic tags is not infinite, and different types of tags also have different erasable times. Generally speaking, the erasable frequency of common ultra-high frequency RFID electronic tags ranges from tens of thousands to hundreds of thousands of times. However, this frequency is already sufficient for most practical application scenarios.

It should be noted that when erasing data from ultra-high frequency RFID electronic tags, specific reader/writer devices are usually required and certain operating procedures should be . At the same time, in order to ensure the security and accuracy of data, some tags also set access permissions and encryption mechanisms.

Ultra high frequency RFID electronic tags achieve efficient data storage and flexible management through their unique storage structure and working principle. Its rewritable feature has brought great convenience to many application scenarios, making item tracking, management, and information updates easier and more efficient. With the continuous development and innovation of technology, ultra-high frequency RFID electronic tags will play an important role in more fields in the future, bringing more convenience and surprises to our lives and work.