| 摘要 |
PURPOSE: To provide merits on transformer manufacture, to prevent the occurrence of distortion and to improve transmission characteristics by using a DC voltage differential amplifier in combination with plural resistors and providing a capacitor between respective inputs. CONSTITUTION: In this negative immittance converter provided with a first transformer I and a second transformer II, the DC voltage differential amplifier 9 is used in combination with the resistors 15, 17, 23 and 28 and the phase shift of 180 deg. is generated between voltages U2 and U1 . Thus, the need of an additional coil in the transformer II is eliminated and the transformers I and II are turned to the same constitution. Also, as the result of feedback by the resistors 16, 17, 23 and 28, the converter does not generate the distortion even at an upper limit value at the time of being driven by full voltage swing. Also, the capacitor 19 between the inputs 29 and 30 of the amplifier 9 cancels negative admittance in frequency conversion larger than 10KHz and even slight instability is suppressed by inserting the capacitors 26 and 27. Thus, the merits on the transformer manufacture are obtained, the generation of the distortion is prevented and the transmission characteristics are improved. |
