US 11,853,826 B1
RFID tag clock frequency reduction during tuning
John D. Hyde, Corvallis, OR (US); Shailendra Srinivas, Seattle, WA (US); Jay Kuhn, Seattle, WA (US); Ronald A. Oliver, Seattle, WA (US); Harley Heinrich, Snohomish, WA (US); Theron Stanford, Seattle, WA (US); and Christopher J. Diorio, Shoreline, WA (US)
Assigned to Impinj, Inc., Seattle, WA (US)
Filed by Impinj, Inc., Seattle, WA (US)
Filed on Jul. 19, 2022, as Appl. No. 17/868,504.
Application 17/868,504 is a continuation of application No. 17/179,546, filed on Feb. 19, 2021, abandoned.
Application 17/179,546 is a continuation of application No. 16/597,866, filed on Oct. 10, 2019, granted, now 10,929,734, issued on Feb. 23, 2021.
Application 16/597,866 is a continuation of application No. 15/985,054, filed on May 21, 2018, granted, now 10,445,535, issued on Oct. 15, 2019.
Application 15/985,054 is a continuation of application No. 14/820,502, filed on Aug. 6, 2015, granted, now 10,002,266, issued on Jun. 19, 2018.
Claims priority of provisional application 62/035,305, filed on Aug. 8, 2014.
This patent is subject to a terminal disclaimer.
Int. Cl. G06K 19/07 (2006.01); G06K 7/01 (2006.01); G06K 7/016 (2006.01); G06K 7/10 (2006.01)
CPC G06K 19/0712 (2013.01) [G06K 7/016 (2013.01); G06K 7/10148 (2013.01); G06K 7/10198 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A Radio Frequency Identification (RFID) integrated circuit (IC) requiring a minimum clock frequency to operate according to a protocol (MFOP), the RFID IC comprising:
a variable impedance;
an antenna port coupled to the variable impedance and configured to be coupled to an antenna; and
a tuning circuit coupled to and configured to tune the variable impedance, wherein the RFID IC is configured to:
extract a first power from an RF wave incident on the antenna;
operate using a first clock frequency less than the MFOP and the first power; and
cause the tuning circuit to tune the variable impedance to increase power extracted from the RF wave; and
after the tuning circuit tunes the variable impedance:
extract a second power higher than the first power from the RF wave; and
operate using a second clock frequency greater than or equal to the MFOP and the second power; wherein
the first power is insufficient for the RFID IC to operate according to the protocol; and
the second power is sufficient for the RFID IC to operate according to the protocol.