Method and system for transmitting the power of a radio frequency type signal received by a radio frequency receiver

Patent metadata

Field	Value
Publication number	US-11190056-B2
Application number	US-202016835945-A
Country	US
Kind code	B2
Filing date	Mar 31, 2020
Priority date	Apr 17, 2019
Publication date	Nov 30, 2021
Grant date	Nov 30, 2021

Abstract

A method and device for transmitting (20) to an electrical element (4) the power of a radio frequency type signal received by a radio frequency receiver (1), e.g., a radio frequency identification (RFID) chip, the receiver (1) having a receiving antenna (2) and a voltage rectifier (3) of the signal received by the antenna (2), the transmission device (20) including a voltage converter (30) connected to the rectifier (3) of the chip and to the electrical element (4). The device includes a control system (40) configured to momentarily derive the signal from the rectifier (3) in order to define an optimal input voltage of the converter (30) for which the input impedance of the converter corresponds to the output impedance of the rectifier (2), and to redirect the DC signal to the voltage converter (30) by providing the converter with an input voltage setpoint corresponding to the optimal voltage.

First claim

The invention claimed is:

1. A method for transmitting, to an electrical element, power of a radio frequency (RF) signal received by an RF receiver, the RF receiver comprising a receiving antenna and a voltage rectifier, the method being performed by a transmission device comprising a control system and a voltage converter, the method comprising:
deriving a direct current (DC) signal from the rectifier to the control system to define an optimal input voltage of the converter for which an input impedance of the converter corresponds to an output impedance of the rectifier,
redirecting the DC signal from the control system to the voltage converter and simultaneously providing the converter with an input voltage setpoint corresponding to the optimal input voltage to permit maximum power to be transmitted to the converter,
converting a signal voltage by the voltage converter, an output voltage of the converter being predefined depending on the electrical element, and
transmitting the DC signal, converted by the converter, to the electrical element,
wherein the control system comprises:
a reference resistance, voltage at terminals of which defines the optimal input voltage, and
a first condenser connected in parallel with and downsteam of the reference resistance to store the optimal input voltage.

2. The method according to claim 1 , wherein the optimal input voltage is obtained by connecting the DC signal from the rectifier to the reference resistance.

3. The method according to claim 1 , wherein the deriving, the redirecting and the simultaneously providing, the converting, and the transmitting are periodically repeated in order to adapt the input impedance of the converter to transmit maximum energy of the DC signal.

4. The method according to claim 1 , wherein the deriving is performed for a first period and the redirecting and the simultaneously providing, the converting, and the transmitting are performed for a second period.

5. The method according to claim 1 , further comprising:
comparing an input voltage of the converter to the input voltage setpoint defined by the system for controlling and modifying a variable resistance of the converter to modify the input voltage of the converter according to the input voltage setpoint.

6. A device for transmitting, to an electrical element, power of a radio frequency (RF) signal received by an RF receiver, the RF receiver comprising a receiving antenna and a voltage rectifier of a signal received by the antenna, the device comprising a voltage converter connected to the voltage rectifier and to the electrical element, wherein the device comprises a control system configured to derive a direct current (DC) signal from the rectifier to the control system in order to define an optimal input voltage of the converter for which an input impedance of the converter corresponds to an output impedance of the rectifier, and to redirect the DC signal from the control system to the voltage converter and simultaneously provide the converter with an input voltage setpoint corresponding to the optimal input voltage,
wherein the control system comprises:
a reference resistance, voltage at terminals of which defines the optimal input voltage, and
a first condenser connected in parallel with and downsteam of the reference resistance to store the optimal input voltage.

7. The device according to claim 6 , wherein the control system comprises the reference resistance arranged between a phase input of the converter and a neutral branch.

8. The device according to claim 7 , wherein the control system comprises a first switch between the first condenser and the reference resistance.

9. The device according to claim 8 , wherein the control system comprises a second switch between the reference resistance and the neutral branch.

10. The device according to claim 9 , wherein the control system comprises a second condenser in parallel and upstream of the reference resistance, and a third switch between the second condenser and the neutral branch.

11. The device according to claim 10 , wherein the control system is configured to control the first switch, the second switch, and the third switch.

12. The device according claim 7 , wherein the converter comprises an operational amplifier connected to an input of the voltage converter, and to the control system to compare an input voltage of the converter with the input voltage setpoint defined by the control system.

13. The device according to claim 12 , wherein the converter comprises a variable resistance connected in series to an output of the operational amplifier.

14. An electronic assembly comprising an electrical element and a radio frequency (RF) receiver, the RF receiver being provided with a receiving antenna and a voltage rectifier of a signal received by the antenna, wherein the assembly comprises a transmission device comprising a voltage converter connected to the voltage rectifier and to the electrical element, wherein the device comprises a control system configured to derive a direct current (DC) signal from the rectifier to the control system in order to define an optimal input voltage of the converter for which an input impedance of the converter corresponds to an output impedance of the rectifier, and to redirect the DC signal from the control system to the voltage converter and simultaneously provide the converter with an input voltage setpoint corresponding to the optimal input voltage,
wherein the control system comprises:
a reference resistance, voltage at terminals of which defines the optimal input voltage, and
a first condenser connected in parallel with and down steam of the reference resistance to store the optimal input voltage.

Assignees

• Em Microelectronic Marin Sa

Inventors

• Saby Jerome
• Petit Maeve
• Coulot Thomas

Classifications

• H02J50/20 Primary

  using microwaves or radio frequency waves · CPC title

• G06K19/0715

  the arrangement including means to regulate power transfer to the integrated circuit · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• H04B1/16

  Circuits · CPC title

• H02J50/12

  of the resonant type · CPC title