Power management in radio frequency devices
First Claim
Patent Images
1. A radio frequency identification (RFID) tag for identification of animals, comprising:
- a first antenna;
a memory, the memory being configured to store data;
a storage unit, the storage configured to receive and store power from a current induced in the first antenna;
a transmission unit, the transmission unit being configured to retrieve the data stored in the memory and to transmit at least a portion of the data via the first antenna on a first carrier frequency; and
a power circuitry, the power circuitry configured to determine the power stored in the storage unit and to supply the power from the storage unit to the transmission unit at intermittent intervals only when sufficient power is stored to enable the transmission unit to retrieve data from memory and to transmit the data successfully.
8 Assignments
0 Petitions
Accused Products
Abstract
The invention is directed to an improved RFID system. The system provides a tag having a power management unit that selectively powers a transmission unit to transmit at least a first signal having a first frequency. The tag can be configured to transmit a second signal having a second frequency as well. The power management unit selectively powers the transmission unit based on the level of power stored in the tag, a duty cycle associated with the tag, or a combination of the two.
80 Citations
29 Claims
-
1. A radio frequency identification (RFID) tag for identification of animals, comprising:
-
a first antenna; a memory, the memory being configured to store data; a storage unit, the storage configured to receive and store power from a current induced in the first antenna; a transmission unit, the transmission unit being configured to retrieve the data stored in the memory and to transmit at least a portion of the data via the first antenna on a first carrier frequency; and a power circuitry, the power circuitry configured to determine the power stored in the storage unit and to supply the power from the storage unit to the transmission unit at intermittent intervals only when sufficient power is stored to enable the transmission unit to retrieve data from memory and to transmit the data successfully. - View Dependent Claims (2, 3)
-
-
4. A method of operating an RFID tag having an antenna and a transponder, the method comprising:
-
entering an energy transfer phase for a first time period, the energy transfer phase including; receiving a carrier signal at the antenna of the RFID tag; inducing a current from the carrier signal received at the antenna; storing power from the current induced at the antenna; and entering a transmit phase for a second time period, the transmit phase including; powering the transponder with the stored power; and transmitting a response signal from the antenna. - View Dependent Claims (5, 6, 7, 8)
-
-
9. A monitoring system comprising:
-
a base station, the base station configured to transmit a carrier signal and to receive response signals; a first RFID tag, the first RFID tag including; an antenna, the antenna configured to receive the carrier signal from the base station and to transmit a response signal to the base station; wherein the first RFID tag begins transmitting the response signal to the base station after receiving the carrier signal from the base station; and wherein the first RFID tag stops transmitting the response signal to the base station at a predetermined time. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A radio frequency identification (RFID) tag for identification of animals, comprising:
-
a first antenna; a memory, the memory being configured to store data; a storage unit, the storage configured to receive and store voltage from a current induced in the first antenna; a transmission unit, the transmission unit being configured to retrieve the data stored in the memory, to transmit at least a portion of the data via the first antenna on a first carrier frequency, and to transmit at least a portion of the data via the first antenna on a second carrier frequency; a power circuitry, the power circuitry configured to determine the voltage stored in the storage unit, and to supply the voltage from the storage unit to the transmission unit and to the memory at intermittent intervals only when sufficient voltage is stored in the storage unit to enable the transmission unit to retrieve data from memory and to transmit the data successfully. - View Dependent Claims (21)
-
-
22. A method of operating an RFID tag having an antenna and a transponder, the method comprising:
-
receiving at the antenna of the RFID tag a carrier signal from a base station; inducing a current from the carrier signal;
storing a voltage from the induced current in the transponder;powering the transponder with the stored voltage at predetermined intervals; transmitting a first response signal on a first carrier frequency during some of the intervals during which the transponder is powered; and transmitting a second response signal on a second carrier frequency during others of the intervals during which the transponder is powered. - View Dependent Claims (23, 24, 25, 26, 27, 28)
-
-
29. A monitoring system comprising:
-
a base station, the base station configured to transmit a carrier signal and to receive response signals; and a first RFID tag, the first RFID tag including; an antenna, the antenna being configured to receive the carrier signal from the base station, and a transponder, the transponder including; a memory, the memory being configured to store data, a power storage unit, the power storage unit being configured to store power obtained from the carrier signal received from the base station, a first transmission unit, the first transmission unit being configured to use the antenna to transmit a first response signal to the base station on a first carrier frequency only if a first level of power sufficient to successfully complete the transmission is stored in the power storage unit, and a second transmission unit, the second transmission unit being configured to use the antenna to transmit a second response signal to the base station on a second carrier frequency only if a second level of power sufficient to successfully complete the transmission is stored in the power storage unit.
-
Specification