High Resolution Passive Imaging Using III-V Monolithic Millimetre Integrated Circuits (MMICs) Operating at 200GHz

这是格拉斯哥大学和QinetiQ在毫米波成像领域的联合项目，主要用于安全和安保应用-这是学术界和工业界共同努力实现可操作的下一代领先功能原型成像系统的一个很好的例子。格拉斯哥大学是世界领先的纳米纤维技术和毫米波元件设计中心。Qinetiq是一家国际领先的英国高科技公司，特别擅长生产先进的成像系统。毫米波雷达和成像系统在100-300 GHz频率范围内工作，有多种应用。与红外线不同，毫米波可以穿透雾、灰尘、烟雾和小雨，这使其适用于目标捕获、飞机导航、零能见度条件下的着陆和无人驾驶飞机。毫米波能够被动检测隐藏在衣服下的塑料和金属物体，这使其成为大众运输安全应用的理想选择。此外，用非电离毫米波和太赫兹波研究化学和生物现象，可能导致危险物质的紧凑探测器，并将为医疗诊断工具带来新的机会。此外，毫米波能够穿透几厘米厚的沙子，使其能够进行遥感和排雷作业。工作在100 GHz以上频率的成像和传感系统的关键是实现超高灵敏度的单片毫米波集成电路（MMIC），其中低噪声放大器（LNA）、探测器和天线结合在单个半导体芯片上。LNA的功能是放大从天线接收的信号，使背景噪声保持在低水平。二极管探测器将接收到的信号转换为具有不同阴影强度的像素，从而在天线扫描目标时重建真实的图像。由于当前纳米技术的性能限制以及在超过100 GHz的毫米波频率下的大部分未开发的设计挑战，直接探测技术主要仅在100 GHz以下的频率下被证明。实现超过100 GHz的毫米波频率的优点是：更高的分辨率成像，减少杂波，更小的组件尺寸;因此可以实现更高的图像清晰度，更少的误报警，增加安全系数，降低成本，以及更小的系统体积。MMIC设计用于上述毫米波频率超过100 GHz的应用，特别是工作在200 GHz的下一代成像系统，在技术和设计方面都提出了重大挑战。在技术上，要求晶体管的临界尺寸为50 nm（人类头发直径的0.001倍）和三维纳米结构。在100 GHz以上的集成电路设计中，芯片上生产的所有元件对其周围环境（包括寄生效应）都非常敏感，因此必须考虑每一个毫微微法拉电容和欧姆电阻。为了确保成功的结果，整个项目已被分解为若干任务，每一个任务都将被独立验证。工作在200 GHz的最终原型成像系统将由格拉斯哥大学和QinetiQ公司共同组装和测试，这两家公司都是国际公认的研究小组，拥有成功生产演示系统所需的技术和设计专业知识。该项目将实现更紧凑、更高成像分辨率的系统，为下一代单芯片单元件和阵列成像系统铺平道路。

This is a joint University of Glasgow, QinetiQ project in millimetre-wave imaging, primarily for safety and security applications - an excellent example of academia and industry working together to realise an operational, next generation, leading edge, functional prototype imaging system. The University of Glasgow is a world leading Centre in nanofabrication technology and millimetre-wave component design. Qinetiq is an internationally leading UK high technology company with particular specialism in producing advanced imaging systems.Millimetre-wave radar and imaging systems which operate in the 100-300 GHz frequency range, have numerous applications. Unlike infrared, millimetre-waves can penetrate fog, dust, smoke and light rain which makes them suitable for target acquisition, aircraft navigation, landing in zero visibility conditions and in unmanned autonomous aircraft.Millimetre-waves are able to passively detect concealed plastic and metal objects under clothing making them ideal for mass transportation security applications. In addition, the investigation of chemical and biological phenomena with non-ionising millimetre and terahertz waves may lead to compact detectors of dangerous substances and will enable new opportunities in medical diagnostic tools. Further, the ability of millimetre-waves to penetrate through few centimetres of sand render them capable of remote sensing and landmine clearing operation.The key to imaging and sensing systems operating at frequencies above 100 GHz is the realisation of ultra-high sensitivity Monolithic Millimetre-wave Integrated Circuits (MMIC's) in which low noise amplifiers (LNA's), detectors and antennas are combined on a single semiconductor chip. The function of the LNA is to amplify the received signal from the antenna, keeping the background noise at low level. The diode detector transforms the signals received into pixels with different shading intensities, and hence reconstructing a real image as the antenna scans across the target.Direct detection techniques have primarily been demonstrated only at frequencies below 100GHz, due to the performance limitations of current nano technologies and the largely unexplored design challenges at mm-wave frequencies beyond 100GHz. The advantages for implementing mm-wave frequencies beyond 100GHz are; higher resolution imaging, reduce cluttering, and smaller component size; hence a higher image definition, fewer false alarms, increasing safety factor, reduced cost, and less bulky systems can be realised. MMIC design for the applications mentioned above at millimetre-wave frequencies beyond 100 GHz, and specifically, next generation imaging systems operating at 200 GHz, presents major challenges in both technology and design. In technology, transistors with critical dimensions of 50nm (0.001x the diameter of a human hair), and three dimensional nano structures are required. In integrated circuit design beyond 100 GHz, all components produced on the chips are highly sensitive to their surroundings, including parasitic effects, so that every last FemtoFarad of capacitance an Ohm of resistance has to be considered. To insure a successful outcome, the overall project has been broken down into a number of tasks, each of which will be verified independently. The final prototype imaging system operating at 200GHz will be assembled and tested as a joint effort between the University of Glasgow and QinetiQ, both of whom are well established and internationally recognised research groups with the required technology and design expertise to successfully produce the demonstrator system. This project will allow the realisation of more compact, higher imaging resolution systems, paving the way for the next generation of single element and array imaging systems on a single chip.