| 摘要 |
PURPOSE:To cancel the detection distortion, by setting the resistance ratio between the emitter and the collector of the transistor of the inversion amplifier of a phse compensating circuit, which is connected in series to a linear amplifier, to N>=1 in case that a video is detected with an artificial synchronizing detecting circuit. CONSTITUTION:An input signal is divided into two by buffers 2 and 3 consisting of transistors (TR) Q15 and Q16, and one is inputted to a linear inversion amplifier 9a consisting of TRs Q17 and Q18 and resistances R13-R16, and the number of inversion stages is matched to that of a carrier amplifier system 5 to eliminate the variance of phase difference due to the degree of modulation. Further, a phase delay due to collector resistances R13 and R14 and capacities C3 and C4 is generated in 9b to eliminate an absolute phase difference between the carrier amplifier 5 and the linear amplifier 7. When the obtained input is inputted to bases of TRs Q3 and Q6 of a multiplying circuit 6, the ratio of resistances R13 and R14 of TRs Q17 and Q18 of the inversion amplifier 9a to resistance R15 and R16 is set to N>=1, and the product for the capacity or the parasitic capacity is enlarged to delay the phase furthermore, and the gain of the amplifier 9a is enlarged to reduce the difference between amplifiers 5 and 7. By this constitution, the detection distortion is cancelled. |
