Abstract-340-GHz 3-D Imaging Radar With 4Tx-16Rx MIMO Array

Binbin Cheng,  Zhenmao Cui, Bin Lu,  Yuliang Qin,  Qiao Liu,  Peng Chen,  Yue He,  Jun Jiang,   Xiaoyang He, Xianjin Deng, Jian Zhang, Liguo Zhu, 

https://ieeexplore.ieee.org/document/8404082/

A standoff 3-D imaging radar for security body scan at 340 GHz has been described. This terahertz imager incorporates a multiple input multiple output (MIMO) array as an electronic beam former in a horizontal dimension and an elliptic cylinder as a focusing reflector in elevation. Frequency-modulated continuous-wave (FMCW) emission with 16-GHz bandwidth caused a 10-mm-range resolution after calibration for nonlinearities of the distorted radar signals. The horizontal MIMO array contains 4 transmitters and 16 receivers (4Tx-16Rx) to generate a 64-Tx/Rx full virtual array corresponding to an antenna size of approximately 128 mm, which caused a horizontal resolution of about 14 mm at a distance of 3 m. FMCW signals were transmitted from the 4-Tx sequentially and focused as narrow beam lines by the elliptic reflector to get a 12-mm vertical resolution at 3 m. A fast-scanning mirror swings in the light path to make these beam lines screen in the vertical direction. A 4-Hz frame rate is now possible for a personal screen with a field of view of 2 m × 0.6 m.

Abstract- A Side-Lobe Suppression Method Based on Coherence Factor for Terahertz Array Imaging

Yanwen Jiang,  Yuliang Qin,  Hongqiang Wang,  Bin Deng,  Kang Liu, Binbin Cheng

An imaging method with side-lobe suppression based on coherence factor is proposed to improve the image quality of Terahertz (THz) array imaging, which is validated by simulation and experiments. The imaging results of real-world data demonstrate that the side-lobe can be suppressed by 29 dB using the proposed method.

http://ieeexplore.ieee.org/document/8272383/

Terahertz (THz) arrays can be used to improve the data acquisition speed considerably in realtime imaging applications. However, the THz array imaging usually suffers from the side-lobe artifacts, which leads to a severe decline in the image quality. In this paper, a side-lobe suppression method based on coherence factor is proposed to improve the image quality. The influences of signal-to-noise ratio on the imaging results are analyzed by simulation. Furthermore, the results based on the real-world data validate the effectiveness of the proposed method, which indicates that the side-lobe is suppressed by 29 dB. This paper can benefit the development of THz imaging technique and its applications in real-time imaging realms.

Abstract-Terahertz detectors arrays based on orderly aligned InN nanowires

Xuechen Chen, Huiqiang Liu, Qiuguo Li, Hao Chen, Rufang Peng, Sheng Chu, Binbin Cheng

http://www.pubfacts.com/detail/26289498/Terahertz-detectors-arrays-based-on-orderly-aligned-InN-nanowires

Nanostructured terahertz detectors employing a single semiconducting nanowire or graphene sheet have recently generated considerable interest as an alternative to existing THz technologies, for their merit on the ease of fabrication and above-room-temperature operation. However, the lack of alignment in nanostructure device hindered their potential toward practical applications. The present work reports ordered terahertz detectors arrays based on neatly aligned InN nanowires. The InN nanostructures (nanowires and nano-necklaces) were achieved by chemical vapor deposition growth, and then InN nanowires were successfully transferred and aligned into micrometer-sized groups by a "transfer-printing" method. Field effect transistors on aligned nanowires were fabricated and tested for terahertz detection purpose. The detector showed good photoresponse as well as low noise level. Besides, dense arrays of such detectors were also fabricated, which rendered a peak responsivity of 1.1 V/W from 7 detectors connected in series.