RFID antennas are components used to transmit and receive radio-frequency signals between RFID readers and RFID tags. They come in various shapes and sizes, including linear polarized, circular polarized, patch, and dipole antennas, each suited for different RFID applications and environments. RFID antennas play a crucial role in determining the read range, data transfer rate, and reliability of RFID systems. They are designed to optimize RF energy transfer and ensure efficient communication between RFID readers and tags in diverse operating conditions.