Near field communications reader

摘要

The present application relates to a near field communications (NFC) reader having a power amplifier which has an output that connects to an input terminal of an antenna by means of an antenna filter made up of one or more series resistors and one or more series capacitors. The NFC reader includes means for adjusting the Q factor of the antenna so as to increase the available transmit bandwidth and/or improve the efficiency of the reader. The means for adjusting the Q factor of the antenna may be, for example, a variable resistive component or one or more switches.

主权项

1. A near field communications (NFC) reader, comprising:
an amplifier configured to drive an antenna of the NFC reader; a first antenna filter comprising a first variable resistance and a first capacitor connected in series with the antenna; a first switch connected in parallel with the first capacitor; a controller configured to:
adjust a quality factor of the antenna by adjusting the first variable resistance; andcontrol an operation of the first switch based on a data rate of data to be transmitted by the NFC reader; a second antenna filter comprising a second variable resistance and a second capacitor connected in series with the antenna; and a second switch connected in parallel with the second capacitor and configured to increase the bandwidth available for data transmission by the NFC reader by short-circuiting the second capacitor.