| 摘要 |
PURPOSE:To obtain a stereo demodulation circuit with excellent characteristics, by using a PPM signal from a pulse count detector as a switching signal for direct demodulation. CONSTITUTION:A detector 10 outputs a PPM signal and positive and negative phase PPM signals B and C, and applies a pilot signal D to a subcarrier signal generator 11. Positive and negative phase sinusoidal subcarrier signals E and F obtained from the said generator 11 are respectively applied to switches SW1, SW2, SW3 and SW4 and are switched with the positive and negative PPM signals. In multiplication signals H.I.G and J between the positive and negative PPM signals and positive and negative side carrier signals obtained from the switching, the signals H and G and the said PPM signal A are added to form R-ch signal output and similarly, the signals I and J and the PPM signal A are added to form L-ch signal output. |
