三毫米波目标RCS测量雷达信号处理机的设计与实现

Design and implementation of signal processor of 3mm millimeter wave radar for RCS measurement

毫米波频段目标的雷达截面积(RCS)特性,对于目标识别与分类、飞行器隐身及雷达反隐身等研究工作具有重要意义。实验测量是获得目标RCS特性的有效方法。本文介绍了三毫米波目标RCS测量雷达系统中信号处理机的设计和实现。该信号处理机由数据采集硬件模块和信号处理软件构成,对实时数据采集后进行离线信号处理。信号处理机对非相参输入信号过采样后完成数字下变频和抽取,将基带数据通过USB总线送入计算机处理,采用傅立叶变换(FFT)实现相参积累,并在积累后通过相对标定来测量目标RCS。理论分析和实测结果表明,可提高接收机灵敏度33dB,对目标RCS测量的相对误差小于5%。

The Radar Cross Section （RCS） charateristic of the target in the millimeter wave band is useful in many research fields such as target identification and discrimination, radar anti-stealth techniques, and so on. To obtain the RCS of a target, practical measurement is an effective method. The design and implementation of a signal processor which is used in a 3mm millimeter-waves radar for RCS measurement is introduces. This processor consists of signal processing software and data acquisition module, and accomplishes off-line signal processing after real-time data acquisition. After the oversampling, the noncoherent input signal passes through the DDC module, and is converted into base band data. The base band data is transferred to the computer by USB bus and processed by the software. The processor adopts Fast Fourier Transform （FFT） to undertake the coherent integration. Based on the integration result, the processor obtains the RCS by means of relative calibration measurement. The theoretical analysis and test result show that since the processor can improve the receiver sensitivity about 33dB, the relative measurement error is less than 5% and satisfies the system request.