US 12,131,215 B2
Radio frequency signal modulation by impedance variation
Ivan Olchevski, Geneva (CH); Stefan Meyer, Donneloye (CH); Matthieu Boubat, Lausanne (CH); and Jean-Paul Sandoz, Cormondrèche (CH)
Assigned to MHM Microtechnique Sàrl, Echallens (CH)
Appl. No. 17/312,729
Filed by MHM Microtechnique Sàrl, Echallens (CH)
PCT Filed Nov. 14, 2019, PCT No. PCT/IB2019/059792
§ 371(c)(1), (2) Date Jun. 10, 2021,
PCT Pub. No. WO2020/121085, PCT Pub. Date Jun. 18, 2020.
Claims priority of application No. 18211751 (EP), filed on Dec. 11, 2018.
Prior Publication US 2022/0027583 A1, Jan. 27, 2022
Int. Cl. G06K 7/10 (2006.01); G06K 7/00 (2006.01); G06K 19/067 (2006.01)
CPC G06K 7/10356 (2013.01) [G06K 7/0008 (2013.01); G06K 7/10019 (2013.01); G06K 19/0675 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for transmitting a code comprising a series of juxtaposed symbols from a device to a reader as a RF backscattered radiation comprising:
providing an RFID tag device configured to transmit RF backscattered radiation in response to an impinging RF signal,
emitting with the reader a reference interrogation RF signal at a reference frequency to the RFID tag,
receiving a reference backscattered signal at the reference frequency from the RFID tag in the reader,
emitting with the reader at least a transmission signal at one trans mission frequency to the RFID tag, the transmission frequency being different from the reference frequency,
receiving at least a coding backscattered signal at the transmission frequency from the RFID tag in the reader,
comparing an amplitude of the reference backscattered signal with an amplitude of the coding backscattered signal,
defining a symbol based on whether the amplitude of the reference backscattered signal is greater, equal, or smaller than the amplitude of the coding backscattered signal,
wherein the symbol represents more than one digital bit.