| 摘要 |
<p>Conventional modulation envelope demodulators for amplitude modulated signals (e.g. ASK coded signals RX) contain rectifier elements which extract a baseband signal BB. Disadvantageously, due to a non-linear characteristic of the rectifier elements, an amplitude of the baseband signal BB depends on an amplitude of the high-frequent carrier signal. The present invention discloses an improved demodulation circuit for demodulating of ASK coded or amplitude modulated signals. This is achieved by using a sampling mixer 4 and a phase adjusting regulation loop (5) by means of which the sampling of the ASK coded signal RX at its maxima is performed with high accuracy. Due to the absence of any rectifying elements, the baseband signal BB can be fully extracted from the ASK coded signals RX.</p> |
