Shaped load modulation in a near field communications (nfc) device
AssigneeBroadcom Corporation
InventorDavid S. CLARKE
Life of this patent
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Abstract
A method and apparatus is disclosed to compensate for overshoot and/or undershoot in a transmission sequence by shaping the transmission sequence according to a shaping envelope to lengthen its rise time and/or fall time to provide a modified transmission sequence. The shaping envelope may represent a trigonometric function, a polynomial function, a piecewise function or any other function that lengthens the rise time and/or the fall time of the transmission sequence. The modified transmission sequence adjusts an impedance of an antenna to load modulate a carrier wave that is inductively coupled to it.
Claims20
A near field communications (NFC) device, comprising:
- a controller configured to provide a transmission sequence to be transmitted to another communications device;
- and
- an envelope shaping module configured to shape the transmission sequence according to a shaping envelope to provide a modified transmission sequence and to load modulate an antenna with the modified transmission sequence.
A method of communication in a near field communications (NFC) device, comprising:
- (a) generating, by the NFC device, a transmission sequence to be transmitted to another communications device;
- (b) shaping, by the NFC device, the transmission sequence according to a shaping envelope to provide a modified transmission sequence;
- and
- (c) modulating, by the NFC device, a carrier wave from another NFC device with the modified transmission sequence.
Dependencies are inferred from the claim text.