| 摘要 |
PURPOSE:To introduce AC component of a detected output only, by mixing each DC component of an output from two branched detection circuits in substantially to the same level and phase relation. CONSTITUTION:An AM input signal applied to an input terminal IN11 is amplified into a prescribed level via an AGC amplifier A11, applied to an AM detection circuit DET and AM-detected. The detected output from the DET is divided into two; one is applied to an input terminal of a differential amplifier A12 directly and another is inverted at a buffer amplifier A13 and applied respectively. Since the two branched outputs are substantially mixed in the amplifier A12 with the same DC level and phase relation, the DC component of the detected output is cancelled and only the AC component is introduced, allowing to keep the DC level to a constant level without dependency on the input signal carrier level substantially. |
