Near field RFID system with multiple reader coils

• US 20070171992A1
• Filed: 03/02/2007
• Published: 07/26/2007
• Est. Priority Date: 01/26/2006
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Maryam, Rofougaran, Ahmadreza, Safarian, Aminghasem, Shameli, Amin, Flaviis, Franco
• Application Number:
  US11/713,285
• Publication Number:
  US 20070171992A1
• Time in Patent Office: Days
• US Class Current: 375/257
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence

Abstract

A near field RFID system includes an RFID reader and an RFID tag. The RFID reader includes a transmit path and a receive path, wherein the transmit path includes: an encoding section coupled to convert data into encoded data; a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal; a power amplifier coupled to amplify the analog encoded signal; and a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal. The RFID tag that includes: a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields; a power recovery circuit coupled to generate a voltage from the current; and a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.

Claims

1. A radio frequency identification (RFID) system comprises:

an RFID reader that includes;

an encoding section coupled to convert data into encoded data;

a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal;

a power amplifier coupled to amplify the analog encoded signal; and

a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal; and

an RFID tag that includes;

a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields;

a power recovery circuit coupled to generate a voltage from the current; and

a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.

2. The RFID system of claim 1 comprises:

the RFID reader implemented on a first integrated circuit; and

the RFID tag implemented on a second integrated circuit.

3. The RFID system of claim 1, wherein the RFID reader comprises:

a coil controller coupled to the plurality of coils, wherein the coil controller enables the plurality of coils in accordance with an electromagnetic field cancellation avoidance scheme.

4. The RFID system of claim 3, wherein the magnetic field cancellation avoidance scheme comprises at least one of:

frequency diversity; and

time diversity.

5. The RFID system of claim 1, wherein the coil of the RFID tag comprises:

a plurality of traces on a plurality of layers of an integrated circuit.

6. The RFID system of claim 1, wherein the coil of the RFID tag comprises:

system parameters for operating as the coil for a near field RFID communication and as an antenna for a far field RFID communication.

7. A radio frequency identification (RFID) reader comprises:

an encoding section coupled to convert data into encoded data;

a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal;

a power amplifier coupled to amplify the analog encoded signal; and

a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal.

8. The RFID reader of claim 7 further comprises:

a coil controller coupled to the plurality of coils, wherein the coil controller enables the plurality of coils in accordance with an electromagnetic field cancellation avoidance scheme.

9. The RFID reader of claim 8, wherein the magnetic field cancellation avoidance scheme comprises at least one of:

frequency diversity; and

time diversity.

10. A radio frequency identification (RFID) tag comprises:

a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields;

a power recovery circuit coupled to generate a voltage from the current; and

a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.

11. The RFID tag of claim 10, wherein the coil comprises:

a plurality of traces on a plurality of layers of an integrated circuit.

12. The RFID tag of claim 10, wherein the coil comprises:

system parameters for operating as the coil for a near field RFID communication and as an antenna for a far field RFID communication.