NEAR FIELD RF COMMUNICATORS AND NEAR FIELD COMMUNICATIONS ENABLED DEVICES

• US 20100167644A1
• Filed: 08/15/2007
• Published: 07/01/2010
• Est. Priority Date: 08/16/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Lefley, Alastair, Winter, Ian, Wilson, Robin
• Granted Patent: US 8,150,321 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• CPC Class Codes: H04B 5/45 Transponders
• CPC Class Codes: H04B 5/48 Transceivers

Abstract

A near field RF communicator has: an antenna operable to generate an RF signal to enable inductive coupling via the magnetic field of the RF signal between the antenna and another near field RF communicator or RF transponder in near field range; and a signal generator operable to generate a multi-level digital sine wave drive signal to drive the antenna to generate the RF signal, wherein the signal generator comprises a selector operable to select one or more digital sequences to provide one or more digital signals from which the digital sine wave drive signal is generated.

Claims

1-32. -32. (canceled)

33. A near field RF communicator comprising:

an antenna to generate an RF signal to enable inductive coupling via the magnetic field of the RF signal between the antenna and another near field RF communicator in near field range; and

a signal generator to generate a digital drive signal to cause the antenna to generate the RF signal, wherein the signal generator comprises a selector to select one or more digital sequences to provide one or more digital signals from which the digital drive signal is generated.

34. A near field RF communicator according to claim 33, wherein the signal generator is configured to generate a digital sine wave drive signal, for example wherein the selector is configured to select two digital sequences to provide the one or more digital signals.

35. A near field RF communicator according to claim 33, wherein the signal generator is configured to generate the digital drive signal as a discretised representation of an oscillatory waveform with a sampling frequency greater than the frequency of the oscillatory waveform so that the discretised representation comprises series of increasing signal levels alternating with series of decreasing signal levels, for example wherein the sampling frequency is 8, 16 or 24 times the frequency of the oscillatory waveform.

36. A near field RF communicator according to claim 33 wherein at least one of:

the selector is configured to combine digital sequences to generate the digital drive signal; and

the selector is configured to average the combined digital sequences to generate the digital drive signal.

37. A near field RF communicator according to claim 33 wherein at least one of:

one or more digital sequences are pre-stored in a store of the near field RF communicator; and

one or more digital sequences are stored in a look-up table; and

one or more stored digital sequences are variable; and

the communicator is configured to generate one or more digital sequences.

38. A near field RF communicator according to claim 33 wherein the communicator is arranged to receive one or more digital sequences from a host or an external device.

39. A near field RF communicator according to claim 33 wherein the selector is configured repeatedly to select a digital sequence or sequences to generate the digital sine wave signal.

40. A near field RF communicator according to claim 33 wherein the signal selector is configured to select elements of the digital sequence or sequences at a frequency determined by a clock signal.

41. A near field RF communicator according to claim 33 wherein the signal generator is arranged to generate the digital drive signal such that a degree of over sampling is the same as or a multiple of the length of a digital sequence.

42. A near field RF communicator according to claim 33 wherein the communicator is configured to alter the digital drive signal in response to changing environmental influences.

43. A near field RF communicator according to claim 33 wherein the signal generator is operable to generate the digital drive signal in accordance with data to be communicated by the near field RF communicator.

44. A near field RF communicator according to claim 33 wherein the selector is configured to, at least one of:

to select digital sequences in accordance with data to be communicated by the near field RF communicator; and

select and multiplex digital sequences representing different signal amplitudes to effect amplitude modulation; and

select respective digital sequences to represent corresponding amplitude modulation levels.

45. A near field RF communicator according to claim 33 wherein the near field RF communicator is at least one of an NFC communicator, and an RFID reader or transceiver.

46. A near field RF communicator according to claim 33 wherein the NFC communicator is operable under ISO/IEC 18092 and/or ISO/IEC 21481.

49. An electrical device comprising a near field RF communicator according to claim 33, for example wherein the near field RF communicator is integrated within or dispersed within the functionality of the electrical device.

50. An electrical device according to claim 49, wherein the near field RF communicator comprises at least one integrated circuit within the electrical device.

51. An electrical device according to claim 49, wherein the device comprises at least one of a mobile telephone, a personal digital assistant, notebook, a personal or desk top computer, a computer peripheral such as a printer, or other electrical device such as a portable audio and/or video player.

52. A portable communications device incorporating a near field RF communicator according to claim 33.

47. A near field RF communicator comprising:

an antenna operable to generate an RF signal to enable inductive coupling via the magnetic field of the RF signal between the antenna and another near field RF communicator or RF transponder in near field range; and

a signal generator operable to generate a multi-level digital drive signal representing a sine wave to cause the antenna to generate the RF signal.

48. A near field RF communicator according to claim 47, wherein the signal generator comprises a selector operable to select one or more digital sequences to provide one or more digitals from which the digital drive signal is generated.