What is the effective range of radio waves received by the reader?

The receiving range of the reader is affected by many factors, such as the frequency of radio waves, the size and shape of the tag, the energy of the reader, the interference of metal objects, and other radio frequency devices. In general, the receiving distance of low-frequency passive tags is within one foot, the receiving distance of high-frequency passive tags is about three feet, and the receiving distance of UHF tags is ten to twenty feet. For semi-active and rfid active tags that use batteries, the reader can receive signals from three hundred feet or more. For low-frequency and high-frequency radio frequencies, if the size of the tag and reader antenna are the same, the receiving distance can be calculated by multiplying the diameter of the antenna by 1.4. This rule applies if the diameter is less than thirty centimeters.

What do LF, HF and UHF stand for?

Like the radio we listen to, the radio frequency tag and reader must be modulated to the same frequency to work. LF, HF, UHF correspond to radio frequencies of different frequencies. LF stands for low frequency radio frequency, around 125KHz, HF stands for high frequency radio frequency, around 13.54MHz, UHF stands for ultra-high frequency radio frequency, in the range of 850 to 910MHz.

Why use different frequencies?

There are 4 kinds of frequency bands in operation, low frequency (125KHz), high frequency (13.54MHz), ultra high frequency (850-910MFz), microwave (2.45GHz). Each frequency has its characteristics and is used in Different fields, so to use it correctly, you must first select the appropriate frequency.

Do all countries use the same frequency?

No, the UHF in Europe is 868MHz, and the UHF in the United States is 915MHz. Japan currently does not allow UHF to be used in radio frequency technology. The government has also adjusted the power supply of the reader to limit its impact on other devices. Some organizations are encouraging the government to lift restrictions. Label and UHF RFID reader manufacturers are also developing systems that can use different frequencies to avoid these problems.