Gain uncertainty in commercial uhf rfid fixed reader antennas and its effect on tag read accuracy

Abstract

Ultra High Frequency (UHF) Radio Frequency Identification (RFID) is a type of RFID technology that is being widely used in recent days. The fixed UHF RFID readers use tuned antennas for far-field power transmission. The gain specified in the reader antennas’ datasheets are often not accurate and vary between manufacturers. This paper presents an experimental method to analyze the gain uncertainty through the path loss measurements. Four commercially available similar sized fixed UHF RFID reader antennas are chosen for this experimentation. The commercial antennas are also benchmarked using an RFID tag for its read rate, read count and the tag`s return signal strength. The impact on the gain uncertainty in RFID applications is also discussed.