| 摘要 |
<p>PURPOSE:To detect an object with a low elevation angle, by dividing a element antenna and a power supply circuit into a center part and a peripheral part, and connecting the input terminal of the power supply circuit of the center part to the input terminal of the power supply circuit of the peripheral part with hybrid circuits respectively. CONSTITUTION:The antenna element is divided into the center part 7a and the peripheral part 7b, and sub array antenna 8a and 8b are formed respectively. Distributors 9a and 9b are connected to the sub array antennae 8a and 8b, and furthermore, they are connected to the hybrid circuits HYDs 10a and 10b, then a sum signal and a differential signal are obtained. By inputting the sum signal and the differential signal to the HYDs 11 and 12, sum signals and differential signals A, D can be obtained. An antenna characteristic is reversible at the time of transmission and reception. At this time, by inputting a high frequency signal to the sum signal terminals A and C, it is distributed to the same phases with the HYDs 10a and 10b, and is distributed to the same phases with the distributors 9a and 9b at the center part and the peripheral past, and prescribed distribution are performed on the antenna devices 7a and 7b at the center part and the peripheral part. In such way, it is possible to obtain a radiation pattern formed symmetrically in an upward and a downward directions having the maximum value in a front direction, and to detect the object with the low elevation angle.</p> |
