To continuously cause directivity to change, with a simple configuration.

A radar transmission signal, sent from a transmission signal generating means 1, is given to a power distribution revision means 2 through a circulator 5. The power distribution revision means 2 dynamically changes power distribution of a radar transmission signal to a feeding point, so as to be fed to a plurality of feeding points A, B, C configuring a feeding means 3 with a desired power in real time. Thus, the directivity of an antenna 4 can be changed continuously.