The distance between read and write tags is affected by the performance of the tag, the output power of the reader, and the gain of the selected antenna. Because writing requires higher microwave energy than reading, the distance to read the tag is twice or more than the distance to write the tag. In addition, the performance index given by the product is measured under ideal conditions, actual use due to environmental interference and other factors, the actual index should be 30% off.
The factors affecting the reading and writing distance are:
1.Interference signals: such as RF signals radiated by local wireless data networks, adjacent automatic identification devices, and other devices. The influence of these noise sources can be eliminated or reduced by adjusting the installation position and direction of the antenna.

2.Attenuation/reflection: almost every object in the rf signal path causes some degree of attenuation. At the same time, due to the multipath effect, some blind corners will be formed in the reading area. By carefully adjusting the installation position of the antenna, the attenuation and multipath effect of the rf signal caused by obstacles can be minimized. Reflections from the metal or metallized surface behind the tag can also affect the attenuation of the signal. In some cases, this effect can increase the reading distance slightly.

3.The connection of antenna joint will seriously affect the performance of the system.

4.When the polarization direction of the electronic tag is inconsistent with that of the antenna, the read-write distance will be affected. When the electronic tag plane is perpendicular to the reader antenna plane, it is impossible for the reader antenna to communicate with the electronic tag no matter how polarized the reader antenna is.

5.Interference between multiple electronic tags occurs when the spacing is less than 10cm and the distance is equal to the antenna. In order to avoid mutual interference caused by multiple electronic tags installed on the same object, two electronic tags installed on the same object should be separated by a sufficient distance.