How to achieve the best reading range of RFID technology?
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- Nov 3,2023
How to achieve the best reading range of RFID technology?
As we all know, RFID readers have a certain reading range. According to the frequency band of passive RFID, the reading distance of low-frequency RFID is shorter than 10cm, and the reading distance is proportional to the size of the tag. High-frequency RFID has good resistance to metal and liquid interference, and the reading distance is mostly within 1m. The ultra-high frequency reading and writing distance is longer, usually 3 to 5m, and the longest can reach 20m.
In addition, the reading range of RFID electronic tags depends on whether the tag is active or passive. Based on active tags broadcasting signals, their reading range is 100m or more longer than passive tags. However, the reading range of passive RFID tags depends on many factors, such as: the operating frequency of the RFID tag, the power of the RFID reader, or interference from other RF devices.
What is the difference between passive tags and active tags? Active RFID tags have transmitters and their own power source (usually a battery). The power supply is used to run the microchip's circuitry and broadcast the signal to the reader (the way a cell phone transmits a signal to a base station). Passive RFID tags have no batteries and are activated by electromagnetic wave energy emitted by the reader. In most cases, semi-active tags are often in a dormant state and do not send out RFID signals to the outside world. The tags will only be awakened when they enter the radio frequency signal range of the reader. Active and semi-active tags are used for RFID tracking of high-value goods that need to be scanned over long distances (such as rail cars on tracks), but they cost more than passive tags, which means they cannot be used for low-cost goods .
Typically low-frequency and high-frequency RFID tags read tags from a range of 1 meter, while ultra-high frequency (UHF) tags read from a range of 3 to 6 meters. And an RFID integrated reader with a large-gain RFID antenna can increase the reading range of passive tags to 20 meters or longer.
The relative position of the RFID tag antenna and the reader antenna will affect the reading effect
When the electronic tag antenna and the reader antenna are arranged in parallel, the electronic tag can identify the maximum value of the reading range. However, when the electronic tag antenna and the reader antenna are arranged vertically, the electronic tag is able to identify the minimum value of the read range.
At the same time, we also need to consider the material of the management object, because different materials have different effects on RFID signals. For example: metal or liquid items will need to use special tags, because metal and liquid will affect the RFID signal, resulting in a reduction in the reading range or even inability to read.
The size of the RFID tag will affect the reading effect
Generally speaking, the larger the RFID tag, the farther the read range is. For example, a coin-sized tag and a mobile phone-sized tag. Obviously, the mobile phone-sized tag will have a larger reading range than the coin-sized tag. A larger tag size will provide a larger receiving area for the antenna, which can provide better read range.
When choosing RFID reader equipment, how to choose reliable equipment?
First of all, when choosing, you should choose the appropriate product based on the specific usage scenario. For example, in the inbound and outbound management of warehousing, Honglu fixed RFID readers can be deployed on gantry or other devices to verify the incoming and outgoing vehicles and their cargo and system task orders. While moving goods safely, it saves manpower and inventory time and completes goods inventory efficiently. During warehousing inventory, handheld RFID readers are used to collect cargo label information between shelves. After collecting the data, the data is uploaded to the backend through WiFi or other communication interfaces to complete the inventory without manual data entry.
Secondly, when selecting an RFID reader, you need to consider the reading speed and reading distance of the reader after combining the tag. The reading and writing distance of the reader is related to the power it transmits. The higher the transmission power, the farther the reading distance of the device is. In addition, the reading and writing distance of the RFID reader will also be affected by the antenna and environmental factors.