0.67 THz高分辨力成像雷达

0.67 THz high resolution imaging radar

摘要:

为达到厘米甚至亚厘米级的成像分辨力，从电子学角度出发，设计并构建了0.67 THz线性调频连续波(FMCW)成像实验平台。平台通过将Ka波段带宽1.2 GHz、功率2 W的线性调频信号24倍频，获得0.66 THz~0.688 8 THz的发射信号，功率约为1.2 mW，接收端的回波经过谐波混频完成去斜(Dechirp)形成2.4 GHz中频信号，二次变频后经高速采样送入信号处理机箱完成成像。雷达发射信号带宽为28.8 GHz，经系统非线性校正处理后，成像分辨力达到1.3 cm，验证了太赫兹雷达的高分辨成像能力。

Abstract:

A 0.67 THz imaging radar is designed and constructed by using Frequency Modulated Continuous Wave(FMCW) technique. The peak output power of the transmitting signal is about 1.2 mW with a bandwidth of 0.66 THz-0.688 8 THz, which is attained by using a×24 frequency multiplication chain fed by a Ka-band 27.5 GHz-28.7 GHz linear frequency-modulated input source with 2 W driving power. After reflecting, the received signal is de-chirped by a×12 multiplier chain pumping Subharmonic Receiver Mixer(SHM) to get a 2.4 GHz IF signal. With an operating bandwidth of 28.8 GHz, the range resolution of terahertz radar is about 1.3 cm after calibration procedure compensating for signal distortion from radar waveform nonlinearities. Experiment results demonstrate the high resolution imaging ability of terahertz radar.