| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a pulse Doppler radar apparatus which can track a frequency stably when a mounted mother machine is in a state that it nearly tracks a target by a method wherein an adjusting means is controlled in such a way that the amplitude of the composed signal of outputs from a main antenna and from a guard antenna becomes minimum. SOLUTION: The amplitude and the phase of a received signal at a wide directivity guard antenna 16 installed in the opening central part of a main antenna 4 are adjusted by a variable attenuator 18 and a variable phase shifter 19. An obtained signal S20 and a received signal S18 from the main antenna 4 are composed by an electric power composer 20. A receiver 6 to which a composed signal S21 is input generates a video signal S13. A signal processor 8 to which the signal is inputted computes the guide lobe angle of the guard antenna 16 anticipating a side lobe clutter region which radiates the same component as the Doppler frequency of a moving target when a mounted mother machine is in a state that it nearly tracks the target. Then, both adjusting means 18, 19 are controlled by a set value which is computed in such a way that the amplitude of a composed signal 21 in its angle of depression becomes minimum. As a result, a frequency can be tracked stably when a side lobe clutter receiving level is lowered and when the mounted mother machine is in a state that it nearly tracks the target.</p> |
