PURPOSE: To obtain an output composite signal of a high level by delaying a signal from plural signal processing systems with a simple constitution and correcting a loss at the time of matching time base.

CONSTITUTION: Receiving signals S1a, S1b from parabolic antennas 21, 22 are processed through mixers 23, 24, a local oscillator 25, an infinite phase shifter 26, variable amplifiers 27, 28, and an amplification controller 32, and a level of an IF signal of an input/output end part of delay lines 33, 34 is detected by executing an envelope detection by diodes 40, 41, 44 and 45. By this detected voltage, amplification controllers 42, 46 vary an amplification degree and correct a loss being an input/output end level difference of the delay lines 33, 34. Thereafter, the phase is controlled to the same phase by a phase difference detector 37 and the infinite phase shifter 26, and also, by synthesizing them, a composite output signal so is obtained.