| 摘要 |
PURPOSE:To easily cope with multiple beams with an antenna system and, at the same time, to improve the beam scanning characteristic of the device, by providing an auxiliary parabolic reflection mirror which commonly uses a focal point with a main parabolic reflection mirror and exciting the auxiliary parabolic reflection mirror by means of a Luneberg lens and feeding antenna. CONSTITUTION:A main parabolic reflection mirror 1 and auxiliary parabolic reflection mirror are provided with a focal point being commonly used by them and a Luneberg lens 7 and feeding antennae 81 and 82 which excite the reflection mirror 2 are installed. By means of the antenna 81 the lens 7 generates excited plane waves and the waves are again converted into plane waves by the reflection mirror 2 and radiated to the space from the effective area of the reflection mirror 1. Moreover, by arranging the antenna 82, beams corresponding to rays 52-62 can be obtained easily. When the radius of the lens 7 and wavelength are represented by R and lambda, respectively, the maximum distance (d) between the lens 7 and reflection mirror 2 is set to one which is equal to or smaller than the value shown by the formula and the maximum diameter of the lens 7 is set to one equal to or smaller than the maximum diameter of the reflection mirror 2. In this way, this antenna system can be used for multiple beams easily and its beam scanning characteristic can be improved. |
