Abstract: Disclosed are a device and a method for calibrating a frequency of a transponder applicable to an RFID system. The device may comprises: a pulse generating unit configured to generate a sequence of pulses based on a PIE symbol sequence from an interrogator of the RFID system; a counting unit configured to count clock cycles of a clock signal based on the generated pulses, wherein the transponder operates based on the clock signal; and a calibrating unit configured to calibrate a frequency of the clock signal towards a target frequency based on a comparison of the counted number of clock cycles with a reference number associated with the target frequency.