Radio Frequency Identification (RFID) has become quite popular over the last few years. Many businesses have adopted this technology to shift their operations to the next level. It is safe to say that most business owners have moved towards RFID, and those who didn’t will indeed adopt it in the near future.
The RFID system has two major components; the reader and the tag. Many people use these devices but don’t know how they exactly work. As a business owner, you should know about the technical details of RFID readers and tags. This article will walk you through everything that you need to know about the reader transmit power. After all, it is the power that allows the RFID system to work over long distances.
What Is Reader Transmit Power?
As the name suggests, the reader transmits power is the amount of output power that is sent by the reader to the RFID antenna. The unit of measurement is dBm (decibels-milliwatts). Sometimes, the power is also measured in Watts (W) or milliwatts (mW). Every manufacturer sets their own unit. You can easily shift between the units by converting the value using the conversion table. For your reference, one dBm equals 1.26 mW.
Difference between Reader Transmit Power and System Output Power
Many people fail to understand the difference between the reader transmit power and the system output power. They consider the two to be the same, however, that’s not true. Reader transmits power is the power sent out by the reader to the RFID antenna, while the system output power is the overall power transmitted by the RFID system. The antenna gain, cable losses, and the reader’s transmit power are all taken into consideration while deciding the RFID system output power.
Reader Transmit Power and Sensitivity
Another misconception that floats in the air is regarding the reader sensitivity and transmit power. Again, both terms are different. The reader transmits power which is the amount of power the RFID reader sends to the RFID antenna, while the reader sensitivity is the lowest power signal which it can detect. In technical terms, reader sensitivity is the lowest received signal strength indicator of the signal sent by the tag. It determines how “sensitive” the RFID reader is by measuring the lowest value of power it can detect.
What Is the Maximum RFID Reader Transmit Power?
The maximum permitted transmit power of an RFID reader depends on the operating country, frequency band, applicable regulations, and reader and antenna configuration.
When evaluating RFID reader power, it is important to distinguish conducted output power from radiated power. Conducted output power is the RF power delivered by the reader to the antenna, while radiated power also depends on antenna gain and cable losses. These factors must be considered together when determining regulatory compliance.
For example, U.S. FCC regulations specify different requirements depending on the operating frequency, modulation, and antenna conditions. European UHF RFID systems must also comply with the applicable regional frequency and radiated-power limits.
When selecting an RFID reader, verify that its power settings and antenna configuration comply with the regulations in your target market. The appropriate transmit power should also match your required read range, tag type, antenna placement, and operating environment.
