To provide a technique for easily adjusting a received polarized wave angle in a state where a coverter integrated primary radiator is fixed to an arm.

A dielectric plate 3 is fixed at the inner side of a water proof cap 2 and the dielectric plate 4 is fixed to a circular waveguide 1 in a rear part 1c so as to make 45° against respective probes 5a and 5b. The water proof cap 2 is turned and the dielectric plate 3 is adjusted to the position of 45° against the respective H-polarized wave and V-polarized electric wave to be received. H-polarized wave is converted into right-hand circularly polarized wave and V-polarized wave ais into left-hand circularly polarized wave in the center part 1b of the circular waveguide 1 being out of the dielectric body 3. The right-hand circularly polarized wave and the left-hand circularly polarized wave of the center part 1b of the circular waveguide 1 are respectively converted by the dielectric plate 4 which is fixed to the rear part 1c of the circular wave guide 1, the right-hand circularly polarized wave becomes linear polarized wave in a probe 5a direction, the left-hand circularly polarized wave becomes that in a probe 5b firection and they are efficiently received by the respective probes.