| 摘要 |
PURPOSE:To increase the beam width at a high frequency band without deteriorating the radiation characteristics of a low frequency band, by using a frequency selecting surface plate FSRS to form a subreflector and also providing another subreflector at the rear side of the first subreflector. CONSTITUTION:An FSRS plate forming a subreflector 2' functions as an HPF to reflect a low frequency band Fl of the radio wave radiated from a primary radiator system 3 and to transmit a high frequency band Fu. Thus the FSRS plate gives the radiation characteristics of the normal beam width to a low frequency band. While a concave subreflector 4 irradiates through its radius (ru) the center part of a main reflector 1 against a radio wave of a band Fu. The beam width of an antenna is adversely proportional to the opening radius of the reflector 1. Thus it is possible to increase the beam width at a high frequency band by reducing the radius (ru) of a reflector 3. |
