The Theory Studies And Realization Of Synthetic Wideband On Millimeter-Wave Seeker

The synthetic wide-band technique is a hot point of radar system research. Making use of the synthetic wide-band technique can decrease difficulty of realization of the whole radar system and it can achieve high range profile of targets. Based on high range profile, the angle tracking of high resolution can be obtained. There are several ways to achieve high range resolution. In this dissertation ,not only the theory analysis ,but also engineering application study of both a stepped frequency and an intra-pulse chirp and inter-pulse stepped frequency are completed. In this dissertation, it's focused on the theory and application study of both a stepped frequency and an intra-pulse chirp and inter-pulse stepped frequency signals. the theory of stepped frequency is firstly discussed. The inter-parameter relationships of frequency interval, pulse width, sampling interval and sampling time are analyzed and some analysis results are given. Besides above all, speed effect on synthetic wide band is discussed. Future more, the signal of the intra-pulse chirp and inter-pulse stepped frequency is analyzed and its ambiguity function is derived to show that the signal can obtain high range resolution. Feasibility of making use of the signal to achieve synthetic wide band is proved and the way of engineering realization is discussed. The relation between frequency interval and bandwidth is analyzed and analytical results are given. The compensation methods for moving target echoes are widely described and some new methods are put forward. Then several concrete questions to realize millimeter seeker based on the theory of the intra-pulse chirp and inter-pulse stepped frequency are described in detail, such as the correction method of amplitude and phase for three channel receiver, the error research for I/Q detector, the effect study of digital phase detector on angle tracking, the detection methods for small targets and so on. Concerned with actual seeker system, the radar three-dimension imaging is discussed. Some results of simulations are shown for three-dimension imaging and several actual millimeter three-dimension images are given. At last the design and realization of millimeter seeker are described. Some systematic parameters and chief sub-systems are briefly analyzed and the realization diagrams are given. A series of tests are finished for the developed millimeter seeker and the main test results are given. The results show that the theory of intra-pulse chirp and inter-pulse stepped frequency is correct and feasible.