Signal Analyzer Design Of CW Ranging Radar And Study For Relation Theory And Algorithm

In order to accommodate new requirement of shooting range, modern radar can not only measure velocity and angle of targets, but also measure range of targets. So it is very important to menufacture multiple frequency continuous wave (CW) ranging radar. All work of this thesis surrounds pivotal technics of multiple frequency CW ranging radar and design of signal analyzier. Following issues are investigated.On the principle of multiple frequency CW ranging, the thesis presents a new multiplefrequency ranging method------quadratic difference frequency ranging. These aspects such asranging principle, rules of frequency selection, requirement of signal-to-ratio (SNR) satisfied with solving unambiguity and ranging precision are discussed in detail. By comparing with uneven multiple frequency ranging, their advantage and disadvantage are given. It provides stable theory basis for design of multiple frequency CW ranging radar. On the basis of analyzing the localization of dual frequency ranging and multiple frequency ranging, the paper presents a new ranging approach that first captures target using multiple frequency ranging, then tracks target using dual frequency ranging. The new approach effectively solves the localization in enlarging maximum unambiguous range while improving ranging precision.On the acceleration compensation, the thesis analyzes the effects of target's acceleration on several outputs of a linear-phase matched filter based on FFT, such as the output SNR loss and the constraint on optimal accumulative time. Then basic principle of dual frequency ranging when target is maneuverable is analyzed. Detection performance based on peak value detection in frequency domain is deduced in detail. A new method for parameters estimation of LFM signals is presented at low SNR using non-stationary signal processing technology. Ranging performances are compared before and after acceleration compensation by simulation.On the correction of quadrature demodulation errors, the thesis analyzes the effect of channels imbalance of quadrature demodulation receiver on dual frequency ranging. A new correction method is presented based on time average. Simulation results prove the validity of correction methods.On the quantization noise, the thesis analyzes quantization noise of two kinds of quantization models including uniform quantization and local minimization quantization.Variances of quantization noise and their according SNR losses are obtained for the Guass noise. Losses of ranging performance for low bits quantization are analyzed by simulation. It can be concluded that using low bits quantization (one bit or two bits) can be satisfied when the requirement of ranging precision is low. So memory space of sampling data is reduced and observation time of target is extended.On the design of signal analyzer, first the thesis gives makeup and connection relation of multiple frequency CW ranging radar terminal system. Then collective design and makeup of signal analyzer are simply introduced. Finally software and hardware design of signal analyzer are researched deeply.