Perspective on active submillimeter electromagnetic wave imaging using CMOS integrated circuits technologies

Abstract

The performance of CMOS transmitters and receivers operating at the submillimeter electromagnetic wave frequencies have sufficiently improved for use in active transmission and reflection-mode imaging applications that have the potential for broad deployment and utilization. Imaging integrated circuits have the potential to be large in area to support a high number of pixels along with digital backend processing circuits. For high volume imaging applications that may eventually be included in automobiles, smartphones, laptops, tablets, and others, a large manufacturing capacity to support the volume of large area ICs is necessary. For this, the use of CMOS technologies with a much larger manufacturing capacity is favored. It should be possible to improve the performance of CMOS circuits to increase the range, and operation margin and frequency. The electronically steerable submillimeter-wave reflector technology holds the promise for improving the performance and energy efficiency of submillimeter-wave imaging systems by multiple orders of magnitude, and it is a critical research area. Increasing the operating frequency from 430 to 850 GHz using CMOS integrated circuits to improve the angular resolution by 2X at a given form factor (∼0.15° for a reflector diameter of 15 cm) can make the submillimeter-wave imaging competitive to the LIDAR angular-resolution performance, while providing superior capabilities in visually impaired conditions and making the imaging devices more affordable.

Enabling Applications of Electromagnetic Waves at 0.3–1.0 THz Using Silicon Electronic Integrated Circuits

“…A 320 GHz, 8-element array in SiGe BiCMOS, a 240 GHz, 32-element array, and a compact pixel at 605 GHz in CMOS with improved sensitivity are demonstrated, suggesting the feasibility of coherent imaging with higher SNRs using silicon IC technologies. The SNR that can be achieved using silicon ICs is better than that of commercially available systems operating around ∼300 GHz , for inspections in laboratories, warehouses, and factories. The expected number of systems manufactured and sold, however, is not very high.…”

“…More in-depth discussions of CMOS SMMW imaging can be found in a paper published by the authors. 10 Electronic Smelling Using Rotational Spectroscopy. Electronic smelling can be emulated by gas sensing utilizing rotational spectroscopy, 4 which can be used to identify a wide variety of gases and to quantify their concentrations.…”

“…This suggests that SMMW imagers can be integrated into a form factor consistent with that of smartphones. More in-depth discussions of CMOS SMMW imaging can be found in a paper published by the authors …”

“…Both electrical and optical technologies are adopted to generate and detect terahertz signals, as will be discussed in the second section. The submillimeter electromagnetic waves have a variety of applications, − including those that can be potentially used in everyday life. − The waves can be used for real-time imaging, including 3D through walls for locating wires and pipes; through decorative pieces to detect air voids and cracks; and through low visibility weather conditions like fog, rain, smoke, dust, and others. ,, These waves can also be utilized for electronic smelling using rotational spectroscopy to detect harmful gases, for breath analysis to monitor health, and more . Additionally, the wide bandwidth available in this part of the spectrum can be used for high data-rate wireline and wireless , communication to help meet the ever-increasing demand for bandwidth in the connected world.…”