INPUT DEVIATION COMPONENT ELIMINATION METHOD FOR CAPACITOR-COUPLING TYPE DIFFERENTIAL INPUT CIRCUIT AND CARRIER COMPONENT OUTPUT PREVENTING METHOD FOR PSK MODULATOR USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To eliminate a transient deviation component at input and end of a signal in the differential input circuit employing a coupling capacitor. ;SOLUTION: A step voltage output circuit 9 that inputs a step voltage u(t) via a coupling capacitor 6' is connected to another input terminal Q' of a differential amplifier circuit, where another input terminal Q is connected with a signal source 2 via a coupling capacitor 6. Then, a voltage, including a transient deviation component in the same phase as the input terminal Q, is inputted to the input terminal Q' by raising the step voltage u(t) in synchronization with the time, when the input from the signal source 2 starts and descending the step voltage u(t) in synchronization with the time, when the signal from the signal source 2 ends, so as to allow the differential input circuit to eliminate the transient deviation component.;COPYRIGHT: (C)1998,JPO