| 摘要 |
<p>PURPOSE:To make the equipment low in cost, to detect a target with high accuracy over a wide range, by constituting the equipment so that a narrow band filter is scanned, and also a scan mode can be selected by an antenna elevation angle. CONSTITUTION:A Doppler signal which has been extracted by a phase detector 11 from a received target signal is converted 14 to a digital value and stored temporarily in a memory 18, and it is outputted to match a scan period of a narrow band filter 12, and also, mixed with a frequency of the second local oscillator 20 and generates a center frequency of a filter bank 13, and made to pass through the filter bank 13. In this case, the frequency of the second local oscillator 20 is switched to match a scan mode of the filter bank 13 which has been set in advance by a controlling circuit 25, based on an antenna elevation angle, and mixed with an output signal from the memory 18 and generates a center frequency of the filter bank 13, and made to scan and pass through the narrow band filter 12. Accordingly, by an operation sequence of the controlling circuit 25, it can be detected that how many times of the scan, and how many outputs of the narrow band filter at any degree of the antenna elevation angle have been executed.</p> |
