| 摘要 |
<p>AP-78951 NOISE PROTECTION CIRCUIT FOR AM STEREO COSINE CORRECTION FACTOR The cosine correction factor of a receiver for compatible AM stereo reception is controlled by the amount of high frequency energy present in the demodulated signal. Large amounts of such energy indicate a low signal to noise ratio and cosine correction under such conditions is then not desirable. During periods of excessive high frequency energy, a filter circuit output causes a switching circuit to remove the derived cosine correction factor and cause division of the demodulated signal by a factor of one instead.</p> |
