VARIABLE PHASE SHIFT CIRCUIT

摘要

PROBLEM TO BE SOLVED: To easily use a variable phase shift circuit for communication units driven by a low voltage by constituting vector synthesis transistor couples and variable gain transistor couples with the transistors of one stage. SOLUTION: Two signals which are inputted from input terminals 1-4 and whose phase difference is not zero degree or 180 degrees are current-converted by the vector synthesis transistor couples 11-18 as collector current. The sum and the difference of converted currents are converted into voltage in resistance groups 29-32 and are taken out from output terminals 7-10. Two groups of gain control transistor couples 19-21 and 20-22 control a vector synthesis ratio (k) in accordance with gain control voltage inputted from gain control terminals 5 and 6. Thus, a low voltage operation can be executed compared to a former circuit by providing transistor vertical loading two-stage constitution.