Patent ID: 11960955
Assignee: IMPINJ, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A Radio-Frequency Identification (RFID) reader that transmits commands to an RFID tag using amplitude modulation (AM) of a radio frequency (RF) waveform and is configured to avoid powering-down the RFID tag when changing a frequency of the RF waveform, the reader comprising:
a transceiver configured to transmit RF waveforms; and
a processor coupled to the transceiver and configured to:
transmit an RF waveform at a first frequency, the RF waveform amplitude-modulated with a command;
identify a modulated portion of the RF waveform whose amplitude and duration are suitable for frequency switching;
during the identified modulated portion, switch the frequency of the RF waveform to a second frequency different from the first frequency; and
transmit the RF waveform at the second frequency, wherein an average power of the entire modulated RF waveform is sufficient for the tag to receive the command.