| 摘要 |
<p>PURPOSE:To detect a jamming signal direction, by mounting a jamming wave analyzing circuit for analyzing the rough azimuth and frequency of a jamming signal and a jamming direction detecting circuit for determining the beam number of the jamming signal direction. CONSTITUTION:An auxiliary antenna 21 has fan beam wide within a vertical plane but narrow within a horizontal plane and receives the frequency and azimuth data of a jamming signal. Said frequency and azimuth data are analyzed by a jamming wave analyzing circuit 22 utilizing that a processing time is long as compared with narrow beam electronic scanning. A reference signal generating circuit 19 sets a transmission pulse repeating cycle to one wherein a jamming signal observing time is added to the time necessary for the reception of a usual target signal and generates local oscillation frequency for making said time synchronous to jamming signal frequency. A jamming direction detecting circuit 20 determines the beam showing the max. value in the jamming signal output of each beam with the vertical plane. A signal detecting circuit 24. observes and operates a jamming signal direction from the jamming wave output signal during a jamming wave observing time. By this constitution, the observation of the jamming signal in a band different from target searching frequency.</p> |
