近程谐波目标探测器技术研究

【作者】 陈昌益；

【导师】 庄志洪；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2007， 硕士

【摘要】 近程非线性目标探测器利用目标的非线性特性，通过接收经目标的非线性作用产生的二次散射波来对目标进行探测和识别。一般人工非线性金属结谐波转换效率较低，只适用于近程探测。由于多数自然物并不产生谐波，故探测器的灵敏度只决定于信噪比而与信杂比无关，这样依靠目标的非线性特性就很容易区分目标回波和杂波，提高了目标的识别能力。本文结合目标的非线性模型，分析和推导了谐波目标探测器的散射功率公式；讨论了谐波探测器的系统实现方案；针对发射通道谐波抑制关键技术，对线性功放技术进行了讨论，并重点对前馈技术进行了研究；分析了频综源的相位噪声和环路最佳带宽的计算方法；分析了接收通道的实现方法和提高接收机灵敏度的技术途径，并在此基础上采用ADS软件建立锁相环和接收机前端的仿真模型，对仿真结果作了简要分析。更多还原

【Abstract】 Short rang non-linear detector uses non-linear characteristic of thetarget, and it gets the characteristic information of the target byreceiving the re-radiation wave produced by the target’s non-lineareffect. Then we can identigy the target. Genenrally, the harmonicconversion efficiency of non-linear junction is too low, and it can justguarantee certain operation range. So it fits the short range radar.Because most natural things can not produce harmonic waves, thesensitivity of the detector lies on the SNR but not the singnal-to-clutterratio. So it is easy to distiguish target echo and clutter, and improve thetarget identifying ability.This paper analyses and make a deduction of the second radiationcalculate expression of the target of harmonic detector, And discussesthe realization project of harmonic radar system. Harmonic restraint ofthe transmitter is one of the key techniques of the system, and PA is theprimary nonlinear component of the transmitter system, so thelinearization technique of PA is very important. The report summarizesand compares several usually used linearization techniques, and primarilyinvestigates feedforward technique, lt analyzes phase noise of frequencyproducer and calculation method of best loop bandwidth, and also analysesrealization way of receiver channnel and ways of improving receiversensitivity. Then briefly analyzes the simulation result after makingsimulation models Of PLL and receiver with ADS software;更多还原