RFID reader is one of the important devices for implementing radio frequency identification technology. The reader can not only read the content of electronic tags, but also write data. The process of reading and writing is mainly achieved through wireless communication between both parties. So, what is the working principle of
RFID readers? Firstly, we need to understand the communication method of radio frequency identification, and secondly, we can deeply analyze the specific working principle.
1. The Communication Method of
RFID
Radio frequency identification is carried out through radio waves, and the identification information stored in it is digitized. Therefore, various applications can be easily implemented through encoding technology. As it mainly utilizes radio frequency resources, it must comply with numerous specifications for the use of radio frequencies.
RFID electronic tag: Electronic tags are also known as radio frequency tags, responders, and data carriers.
RFID reader: a device that reads electronic tags.
RFID antenna: It transmits radio frequency signals between tags and readers, and the design of the antenna has an impact on the performance of the reader.
2. Working principle of
RFID reader/writer
The reader/writer communicates wirelessly with the
RFID electronic tag through an antenna. When the electronic tag enters the magnetic field, if it receives a special radio frequency signal emitted by the reader, it can use the energy obtained by the induced current to send out the product information stored in the chip, which can realize the reading or writing operation of the tag identification code and memory data. At present,
RFID readers and writers that are widely used in the market include
RFID integrated readers and
RFID handheld readers.
The circuit composition of an
RFID reader mainly consists of four parts: oscillator, transmission channel, reception channel, and microcontroller.
(1) Oscillator
The oscillator circuit generates RF oscillation signals that meet the requirements of the
RFID system. One path generates the clock signal required by the MCU through the clock circuit, and the other path generates the carrier signal for the operation of the reader/writer through the carrier forming circuit. For example, the oscillation frequency of the oscillator is 4MHz, and after shaping, it provides a 4MHz clock for MCU operation. After frequency division (32 frequency division), it generates a 125kHz carrier wave.
(2) Sending channel
The transmission channel includes encoding, modulation, and power amplification circuits for transmitting commands and writing data to electronic tags.
(3) Receiving channel
The receiving channel includes demodulation and decoding circuits, used to receive response information and data returned by electronic tags. According to the anti-collision capability of electronic tags, the design of anti-collision circuits should also be considered.
(4) Microcontroller Unit (MCU)
MCU is the core of the reader/writer's work, completing tasks such as receiving/sending control, sending commands and writing data to electronic tags, reading and processing electronic tag data, and communicating with high-level application systems.
The above is the relevant analysis of the working principle of
RFID readers.
RFID readers communicate wirelessly with electronic tags through antennas, and can read or write tag identification codes and memory data. At present,
RFID technology has been applied in many industries due to its large storage capacity, long battery life, and multiple communication and expansion interfaces. It is suitable for logistics warehousing, smart retail, manufacturing management, clothing enterprise management, anti-counterfeiting traceability, asset management and other fields.
