| 摘要 |
A communications apparatus 10 has an aerial 12 suitable for transmitting and receiving signals in a near-field communication (NFC) frequency band. A resonant network or tank circuit is connected to the antenna 12, which is configured to adjust a self-resonant frequency of the antenna 12 such that it may transmit or receive in a standard frequency modulated (FM) band. The resonant network may be connected in either a single-ended or differential mode, as may the NFC terminal 18, and may be connected at the antennaâ s common mode point 28 or at points equidistant from the common mode point 18, such as points half way between the electrical centre 18 and the antenna ends 14, 16. Switches may alter the resonant network from a series-resonant circuit when transmitting FM signals or a parallel-resonant circuit when receiving FM signals. An integrated circuit may be provided with the communication apparatus 10. |
