太赫兹(THz)成像技术是一种新发展的高频段成像技术，在军事和安全领域具有重要的应用价值。文中的实波束THz异物探测(FOD)系统未进行宽带幅相失真补偿时,一维像主副瓣比较差，微小目标无法成二维像。考虑到该成像系统采用了高频段易于实现的调频连续波自混频去斜方法，传统的宽带成像系统在信号产生时所实施的宽带幅相预失真补偿方法无法起效，为此，文中给出了实波束THz FOD 系统的一种硬件幅相失真补偿方法。该方法通过对接收机数字下变频的正交数据实施先相后幅的通带失真补偿，完成了THz FOD系统的幅相失真补偿。采用该补偿方法的THz FOD 系统一维像加海明窗主副瓣比>40 dB，可实现对微小目标成二维像。

Terahertz (THz) imaging technology is a newly developed high frequency band imaging technology, which has important application value in military and security fields. When the real wave velocity THz foreign object detection (FOD) system in this paper is not compensated for wideband amplitude and phase distortion, the ratio of sidelobe to mainlobe of one-dimensional image is bad, and the two-dimensional image of tiny target can′t be obtained. Considering that the imaging system adopts the self-mixing dechirp method of frequency modulation continuous wave which is easy to realize in high band, the amplitude and phase predistortion compensation method of the traditional wideband imaging system in signal generation cannot take effect, therefore a hardware amplitude and phase distortion compensation method for the real wave velocity THz FOD system is proposed in this paper. In this method , the amplitude and phase distortion is compensated by implementing the first phase and then amplitude passband distortion compensation to quadrature data of receiver′s digital down conversion in the THz FOD system. After using this method, the ratio of sidelobe to mainlobe with Hamming window of one-dimensional image is more than 40 dB, and two-dimensional image of tiny target can be obtained in the THz FOD System.

TN958