Knowing the key factors of RFID readers will allow you to properly assess their performance and choose the most appropriate one according to your needs.
The core of a RFID reader, in essence, is a radio signal transcriber that simultaneously transmits and receives radio signals with the RFID tag.
This indicates that a RFID reader has to face a combination of usual technological challenges of radio systems with other not so common challenges, which are typical of wireless communication but well known to radar technicians and experts in passive communications, as is the case with RFID.
When choosing a RFID reader, in addition to ensuring it meets the basic characteristics of accuracy, efficiency, flexibility and low radiation noise, you must take into account 6 fundamental and practical factors that will help you determine which RFID reader is the most suitable for your work:
- Sensitivity The reader should be able to detect signals coming from the RFID tag of up to -80 dBm of power, which is the minimum power that can reach it from a RFID tag. Today, it is possible to detect signals of up to -115 dBm. Good RFID readers reach -90 dBm.
- Selectivity It should be able to select the signal from the RFID tag within a vast spectrum of signals, some much more powerful than the later. This aspect is of vital importance, since RFID frequencies work close to telephony frequencies and, if not taken into account, interferences may occur.
- Dynamic reach The RFID reader must be able to simultaneously detect and select signals from several RFID tags that are at different distances, so that the emission powers of the tag can differ by a factor greater than 10,000 difference.
- Work under regulations In Europe, RFID standard allows operating between a 865.6-867.6 MHz frequency band, with a maximum RFID reader power of 2 W ERP. The regulatory entity in Europe is ETSI (European Telecommunications Standard Institute) which follows the EN 302 208 norm.
- Operation in dense environments of RFID readers It is a supplementary standard, not mandatory as legislation, but very useful to be able to withstand interference with other RFID readers. To be in compliance with the EPC Global Gen2 standard, it is necessary to comply with this standard.
- Multi-manufacturer inter-operation It is also a supplementary norm, very useful to be able to work with all types of RFID chip manufacturers and RFID readers, their products being interchangeable without any problem. EPC Global has an inter-operability certification available to the market.
