RFID tags have the advantages of long recognition distance, strong multi-tag recognition ability, fast collection, and not easy to damage. They have been widely used in many fields such as warehousing and logistics, jewelry management, book management, and asset management. However, when multiple UHF RFID tags are read at the same time, the performance of the tags is not as sensitive as a single tag.
What's the reason? ? ? That's because the labels are ‘grabbing’ energy! ! !
The RFID system is mainly composed of a tag (Tag), a reader (Reader) and an antenna (Antenna). The UHF RFID electronic tag recognizes the tag by absorbing the electromagnetic wave emitted by the reader and activating the chip. When multiple tags appear in the radiation area at the same time, the tags with good performance will be read quickly and frequently, thus occupying the radiation energy of the space.
This may cause nearby tags with weak signals to slow down or even not read.
To this end, we conducted the following tests, the phenomena are as follows:
"Grab" energy among UHF RFID tags
Debug the A label with poor performance to a position that can be read continuously, and then slowly approach the B label with good performance from a distance. When the B tag can be read but the A tag cannot be read at the beginning, the critical distance between the two tags is about 12cm, and the two tags can be read at the same time by increasing a small amount of power.
After simulation test, UHF RFID tags will have this phenomenon, which has nothing to do with the chip.
Whether the label of the Impinj R6 chip absorbs the label of the Alien H3 chip or the label of the Alien H3 chip absorbs the label of the Alien H3 chip, good performance will grab the energy of poor performance, and the critical distance is similar.
However, when the power is large enough, or when the overall performance of the tag is good enough, it can be read at the same time. The critical distance is related to the performance of a single tag and the poor performance of two tags.
Therefore, we recommend: labels with a spacing of more than 20cm are the best!
Broadradio is a high-tech enterprise focusing on the RFID, production and sales of UHF rfid hardware for more than 10 years. It has excellent independent innovation capabilities, obtained a number of national and international patents, and has more than 10,000 square meters of R&D and production in South China. The base has more than 500 production employees to ensure production capacity, and is equipped with more than 20 high-standard testing equipment to ensure product quality. It is your ideal partner.
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