Space diversity in-phase synthesis circuit

摘要

PURPOSE:To improve the in-phase accuracy and to prevent an antiphase pulling-in state by performing the phase control with a phase control signal in an in-phase state. CONSTITUTION:1st and 2nd reception signals S1 and S2 are synthesized via the phase shifting means 2 and 3 respectively and outputted as a synthetic signal S3. The means 2 shifts the phase in the direction opposite to that of the means 3, and the means 3 controls the phase of the signal S2 so as to secure the same phase between both signals S1 and S2. A phase comparator means 4 compares the output signals of both means 2 and 3 with each other. Based on the comparison result, a synchronous phase control means 5 holds the phase shifting direction set right before an in-phase state when the state is detected. At the same time, the means 5 produces the control signals to shift the phases of the reception signals at a low phase shifting speed set previously and then stops the production of these control signals when no synchronous state is detected through the preceding comparison. Then the control signals are sent to the means 2 and 3 from the means 5 in a synchronous state for execution of the phase shifting control.