RFID readers mainly use wireless communication to read and write information. In practical applications, some
RFID readers can only recognize tags within one meter, while others can read and write from several meters away. What is the specific effective distance of
RFID card readers related to? It is mainly related to five factors: RF power, antenna gain, azimuth, number of attenuation factors, and total length of antenna feed lines.
What is the effective distance of
RFID card readers related to?
1.
RFID reader output power: If the output power is low, the reading and writing distance of the
RFID device will be small, and if the output power is high, the reading distance of the
RFID device will be long.
2.
RFID reader antenna gain: The smaller the gain value of the
RFID reader wireless antenna, the shorter the reading and writing distance of the
RFID device. Conversely, the higher the gain value of the
RFID reader wireless antenna, the farther the reading distance.
3. Orientation: It is related to the mutual coordination between the polarization orientation and relative viewing angle of the
RFID tag and antenna. When the orientation is consistent, the mutual coordination is improved, and the reading and writing distance is longer. On the contrary, if there is no coordination, the reading distance is closer.
4. The number of attenuation coefficients: The larger the number of attenuation coefficients in R, the closer the read/write distance, and conversely, the smaller the attenuation coefficient, the farther the read distance jumps.
5. The total length of the feeder line is related to the total length of the feeder line connecting the reader/writer and the wireless antenna. The longer the feeder line, the closer the read/write capability distance, and conversely, the shorter the feeder line, the farther the read distance.
When
RFID readers are unable to read information from electronic tags, there are usually three reasons:
1. The reading and writing distance is too far
RFID tags have different application environments and reading distances depending on the manufacturing process. If the reading distance is too far, it will affect the reading effect.
2.
RFID electronic tag damaged
RFID electronic tags contain chips and antennas. If the chip is subjected to external pressure or high static electricity, it may fail. Damaged
RFID signal receiving antennas may also lead to failure. Therefore,
RFID electronic tags cannot be compressed, damaged, or torn. Generally, those with strict requirements will package electronic tags in plastic
Cards to prevent damage.
3. Has an impact on objects
RFID electronic tags cannot pass through metal objects. When the tag is blocked by metal, it will affect the reading distance of the
RFID reader, and even make it impossible to read. The radio frequency information of
RFID electronic tags is also difficult to pass through water, and if isolated by water, the sensing distance will also be limited. Generally speaking,
RFID tag signals can be transmitted through paper, non-metallic or non transparent materials such as wood and plastic, allowing for penetration communication. If the usage scenario is special,
RFID readers and tags with different attributes need to be selected for the usage scenario area. If used in a metal environment, metal resistant
RFID readers can be selected. If used in high temperature and humid environments, it is best to choose high temperature resistant, waterproof and other reading and writing devices.
By understanding the effective distance of
RFID card readers and what it is related to, when designing or selecting
RFID reading and writing devices, people can better combine the usage scenarios, adjust various parameters of the device, and then choose suitable reading and writing devices to maximize their effectiveness.
