| Radar digitization is a development trend of radar. Radar digitization includes digital components replacing most simulation components , digitization generation of radar signal, digital beam forming and digital processing of radar signal, etc. Meter wave radar of circular receiver arrays adopt digitization technique, generating complex waveforms of single carrier frequency pulse and CHIRP with DDS technology, digitization processing echo signal with digital receiver, forming digital beam with DBF technology.Multistatic antenna elements and multichannel receivers are adopted to the metre wave radar of circular receiver arrays, which bring to the array systemic errors. Though engineerings try their best to ensure the coherence among the channels in hardware designing circuit making machine machining, but some errors are avoidless. For example , environmental temperature and humidity, antenna element mutual coupling, the aging of active components and the characteristic with temperature change of active components, etc. Varrious modern advanced signal processing arithmatics form this efect of the errors is sensitive , sometime system errors will result in invalidation of these arithmatics.Because error is an important factor that restricts the radar system, in this thesis , we analyse the efect of amplitude and phase errors to the metre wave radar of circular receiver arrays. The amplitude and phase errors among the channels not only influence the antenna gain, beam width and sidelobe level,but also debases the signal-to-Noise, influence the effects of airspace filter. We used the technique to the amplitude and phase equalization among the channels, introduces the calibrating principle and the system achievement. AT last, this thesis precents the testing results of DBF on the new type radar. In the process of reseach, the thesis adopt statistical analysis to deduce the statistical characteristics of the beam pattern ,and pass most of the simulation test. |
PDF Full Text Request