| 摘要 |
<p>PURPOSE:To detect an object with a low elevation angle, by dividing a element antenna and a power supply circuit into center parts and peripheral parts, and connecting one of the input terminals of the power supply circuit of the center part to one of the input terminals of the power supply circuit of the peripheral part with a hybrid circuit. CONSTITUTION:The element antenna is divided into the center part 7a and the peripheral part 7b, and distributors (power supply circuits) 8 and 9 are connected to them respectively. One of the input terminals of the distributor (power supply circuit)8 and one of the input terminals of the distributor(power supply circuit)9 are connected to the hybrid circuit 10, then, a sum signal and a differential signal can be obtained. By inputting a high frequency signal to a sum signal terminal, it is distributed to two with the same phase, and prescribed distribution are performed on antenna devices 7a and 8a by the power supply circuit 8 at the center part and the power supply circuit 9 at the peripheral part respectively, and a radiation pattern formed symmetrically in upward and downward directions and having the maximum value in a front direction is obtained. A transmission characteristic and a reception characteristic are reversible in the antenna. In such way, it is possible to detect the direction of the object in a direction of the low elevation angle.</p> |
