Introduction to RFID:
RFID (Radio Frequency Identification: Radio Frequency Identification), commonly known as "electronic tag", is a non-contact automatic identification technology. It automatically identifies the target object and obtains relevant data through radio frequency signals . The identification work does not require manual intervention. As a wireless version of the barcode , RFID technology has the advantages of waterproof, anti-magnetic, high temperature resistance, long service life, large reading distance, data on the label can be encrypted, storage data capacity is larger, storage information can be changed freely, etc. Logistics and other industries have brought revolutionary changes.
RFID basic composition:
A radio frequency tag is physically composed of three parts: a tag, an antenna, and a reader.
Tag (Tag): composed of coupling elements and chips, each tag has a unique electronic code, high-capacity electronic tags have a user write area, attached to the object to identify the target object;
Reader (Reader): read (sometimes A device that can also write) tag information, which can be designed as hand-held or fixed;
Antenna: transmits radio frequency signals between the tag and the reader.
RFID Features:
Data storage: Compared with traditional labels, the capacity is larger (1bit-1024bit), the data can be updated at any time, and can be read and written;
reading and writing speed: Compared with barcodes, there is no need to align and scan in a straight line, and the reading and writing speed is faster. Multi-target recognition, motion recognition;
easy to use: small size, easy to package, can be embedded in the product;
security: special chip, unique serial number , difficult to copy; - uniqueness and
durability: no mechanical failure, long life, anti-shock environment.
How RFID works:
The basic working principle of RFID technology is not complicated: the reader sends a radio frequency signal of a specific frequency through the transmitting antenna, and when the electronic tag enters the effective working area, an induced current is generated to obtain energy, and the electronic tag is activated, so that the electronic tag encodes itself. The information is sent out through the built-in radio frequency antenna; the receiving antenna of the reader receives the modulated signal sent from the tag, and transmits it to the signal processing module of the reader through the antenna regulator, and after demodulation and decoding, the valid information is sent to the background host system for processing Relevant processing; the host system identifies the identity of the tag according to the logical operation, makes corresponding processing and control for different settings, and finally sends out an instruction signal to control the reader to complete the corresponding read and write operations.
RFID classification:
According to whether there is a power supply, it is divided into Passive and Active:
Passive Tag (passive):
Passive sensor itself has no power supply, its power supply is from Reader, Reader transmits a frequency to make the sensor generate energy and transmit data back to Reader, it is relatively light, thin and short and has a long service life. The sensing distance is shorter.
Active Tag (active type): The price is higher. Because of the built-in battery, the volume is larger than that of the Passive tag. It has a service life and a longer sensing distance.
According to the level of frequency, it can be roughly divided into three categories: LF, HF and UF:
Low Frequency: 100~500KHz low frequency has short sensing distance and slow reading speed, mainly 125KHz, with good penetration ability;
High Frequency: The sensing distance of 10~15MHz high frequency is slightly longer, and the reading speed is also faster at lower frequencies, mainly 13.56MHz;
Ultra High Frequency/Microwave: Between 850~950MHz (UHF) and 2.45GHz, the sensing distance is the longest, the speed is also the fastest, and the penetration is poor.