13.56 MHz Card RFID

13.56 MHz refers to a frequency of 13.56 million cycles per second. It's commonly used in various wireless communication technologies, especially in RFID (Radio Frequency Identification) systems. This frequency is widely used for contactless smart cards, key fobs, and payment systems. The 13.56 MHz frequency is part of the ISM (Industrial, Scientific, and Medical) radio band, which means it's designated for unlicensed use, making it ideal for devices that need short-range, low-power communication without requiring special permissions.