| 摘要 |
PURPOSE:To realize the titled circuit with a large dynamic range and an excellent carrier suppressing ratio by interposing a conversion circuit between 2 2nd input terminal pair receiving either balanced or unbalanced carrier signal and a corresponding 2nd input pair of a double-balanced differential amplifier circuit comprising a Gilbert multiplier cell. CONSTITUTION:An output of the differential amplifier circuit is connected to each base of twin differential pair transistors (TRs) 1-4 of the Gilbert multiplier cell via a 3rd emitter follower TR comprising a TR 9 and a resistor 38 and a 4th emitter follower TR comprising a TR 10 and a resistor 39. A carrier signal fed to the bases of the TRs 1-4 is subjected to amplitude limit because the resistance of resistors 32, 33 is selected to be small, its peak factor is small and the maximum amplitude level is brought to a low voltage level as stated above, then a large output signal amplitude is obtained by resistors 30, 31 under a limit where the base-collector voltage of the TRs 1-4 is not inverted.
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