| 摘要 |
PURPOSE:To reduce a carrier leak by enlarging the capacity between a base and a collector of a bidifferential transistor. CONSTITUTION:Bidifferential transistors 9-12 constitute an operational amplifier for suppressing the same phase input signal component to the utmost by an output, and obtaining an output to a differential input signal component. In this regard, capacities 13-16 are added between each collector-base of the differential transistors 9-12. In such a state, input signals from carrier input terminals 1, 2 are impressed to each base of the bidifferential transistors 9-12 through emitter follower circuits 3, 4, respectively, analog multiplication is executed by these bidifferential transistors 9-12 and a base band input 19, and a multiplication output is obtained in output terminals 17, 18. In such a way, a carrier leak caused by asymmetry of an element for constituting an analog multiplier of a gilbert cell type can be reduced. |
