PURPOSE: To attain frequency conversion under the same condition at plural antenna terminals and to eliminate complicated wiring between receivers by generating a reference oscillating frequency signal from one of the antenna terminals and using the signal so as to make frequency conversion under the same condition at the other antenna terminal.

CONSTITUTION: Antennas 1A, 1B parted spatially in antenna terminals 7A, 7B receive a radio wave respectively. A frequency conversion signal is fed to signal branch circuits 9A, 9B via coaxial cables 4A, 4B and fed to a signal selection circuit 5 in a receiver, in which a reception signal with a more excellent characteristic is selected. In this case, only the antenna terminal 7A being a master is provided with a reference frequency signal oscillation circuit 8 and a reference oscillation frequency signal fc outputted from the reference frequency signal oscillation circuit 8 is used to make frequency conversion in the antenna terminals 7A, 7B, then the frequency conversion is implemented entirely under the same condition.