| 摘要 |
PURPOSE:To reduce the deterioration in a radiation pattern by adopting a part of a sub reflection mirror as a frequency selective reflection mirror so as to make the beam width of each frequency band nearly equal to each other. CONSTITUTION:The frequency selecting reflection mirror FSR11 acts like reflecting a radio wave in frequency f1 and transmitting that in frequency f2, and a radio wave irradiated to the sub reflection mirror 2 from a primary radiator 3 with an apparent angle of thetam0 of a main reflection mirror 1. The radio wave irradiated with an apparent angle of thetam1 is irradiated in the main reflection mirror Dm1 in an angular range smaller than the angle thetam1 and transmitted through without being reflected on the FSR11 in an angular range larger than the thetam1. Further, the radio wave reflected from the mirror 1 is blocked by the mirror 2 and since the FSR11 shows transmittivity to the f2, the equivalent blocking area is Ds1. Then the relation of Ds0/Dm0approx.=Ds1/Dm1 with respect to the f1, f2 is established. Thus, the relation of lambda1/Dm0approx.=lambda2/Dm1 is obtained, the lambda/D is made nearly equal in the common frequency and the deterioration in the radiation pattern is reduced. |
