| 摘要 |
An FSK transceiver (21) for use in a hearing aid has means for automatic tuning of the transceiver frequency. The automatic tuning means comprises a phase difference detector (26, 27, 28, 29) and a tuning manager (25) adapted to control the frequency of a resonant circuit of the FSK transceiver (21) according to information received from the phase difference detector (26, 27, 28, 29). The phase difference detector (26, 27, 28, 29) measures the phase difference across a component (Ci) of the resonant circuit of the FSK transceiver (21). If the phase difference (A) of a binary FSK symbol is equal to the phase difference (B) of the opposite binary FSK symbol, the resonant circuit is tuned, otherwise the tuning manager (25) performs a tuning procedure in order to minimize the difference |
