公开(公告)号：US20200187032A1

公开(公告)日：2020-06-11

申请号：US16690210

申请日：2019-11-21

Applicant: NXP B.V.

Inventor： Steve CHARPENTIER ,  Ulrich Andreas Muehlmann ,  Stefan Mendel

IPC: H04W24/08 ,  H04B5/00 ,  H04L29/06

Abstract: A contactless communication device includes a near field communication (NFC) module for generating an electromagnetic carrier signal and modulating the carrier signal according to data to be transmitted, and an antenna circuit coupled to and driven by said NFC module with the modulated carrier signal. The device includes an RF front end coupled between said NFC module and said antenna circuit and further includes a protocol detection circuit for detecting a protocol mode in response to an incoming signal received by the device. The protocol detection circuit includes a plurality of filters being adapted to generate an envelope of the incoming signal; a plurality of decoders being adapted to generate an output in response to a respective envelope generated by a corresponding one of the plurality of filters; and a decision unit being adapted to detect a protocol mode based on the output from each of the plurality of decoders.

公开(公告)号：US20190190554A1

公开(公告)日：2019-06-20

申请号：US15907544

申请日：2018-02-28

Applicant: NXP B.V.

Inventor： Radha SRINIVASAN ,  Ulrich Andreas MUEHLMANN ,  Frederic BENOIST ,  Stefan MENDEL ,  Steve CHARPENTIER

IPC: H04B1/12 ,  H04B5/00 ,  H04B17/318

Abstract: Embodiments are provided for a method of operating a receiver system, the receiver system comprising one or more channels, the method comprising: monitoring a residual DC (direct current) offset in a present channel by sampling an output of an analog-to-digital converter (ADC) of the present channel; adjusting a DCO (direct current offset) correction signal that corresponds to the residual DC offset in response to an absolute value of the residual DC offset exceeding a programmable DCO threshold; and subtracting the DCO correction signal from an analog signal provided to the ADC to reduce the residual DC offset below the programmable DCO threshold.