Terahertz Technology for Future Road Vehicles

这项计划将为新一代传感器系统奠定科学基础，该系统将安装在车辆上，以提高安全性和效率。这些传感器足够小，可以不引人注意地安装在车辆上，它将允许实时产生高分辨率图像，智能车辆系统可以读取和解释这些图像，以确定在危险情况下的适当行动，并动态控制车辆以降低燃油消耗。与基础设施和其他车辆共享图像或从图像中获得的信息，也将使整个车辆群的安全和效率得到共同提高。基于这项技术的传感器将对未来的集成汽车交通系统产生影响，支持高效利用可再生能源、低碳排放和增强所有道路用户安全性的智能交通理念。新传感器将利用0.3太赫兹至1太赫兹频率范围的电路和设备技术。虽然这一范围介于无线电频谱的上端和红外线的下端之间，目前还没有被广泛使用，但设备和电路技术将在未来十年内成熟。与较低频率的微波和毫米波或红外和光学频段相比，使用这一频段有几个潜在的优势。与波长成比例，低太赫兹频段所需的天线比微波和毫米波频段的天线小。提高了可实现的图像分辨率。造成这种情况的原因有两个。首先，当波长很短(不到1毫米)时，使用合理的小天线可以产生更窄的波束。其次，当使用如此高的频率时，可用的高带宽使得有可能区分反射信号中更紧密间隔的特征。同时，与红外线和光学系统不同，该波段中的波不容易被道路污垢或降水完全遮挡。在这项工作之前和期间，将高度关注车辆系统的应用，并由汽车行业专家提供输入，以确定未来车辆系统的具体要求。为了生成所需的图像，必须从车辆传输低太赫兹波，在周围环境中传播，并从物体和表面散射。散射波传播回车辆并被传感器天线接收，提供了形成图像所需的信息。该项目的主要研究工作都与成像系统的这些物理方面有关。首先，将确定道路环境的特性，以找到低太赫兹信号可以通过空气、降水、汽车尾气、道路喷雾和空气中的尘埃和砂砾传播的特定频率窗口。这将包括在实验室创造的受控、封闭的人工环境中进行测量和实际道路试验相结合。然后，将分析典型道路场景和表面的散射特性，以确定用于成像的最合适的频率和波形。研究的主要部分将涉及在车辆上实施低太赫兹成像系统所需的天线和波束形成网络的研究。在射频频谱和光学频谱之间的工作提供了开发和合并基于透镜和天线的发射机概念的机会。将研究系统要求，以得出可使用新兴电路和器件技术实现的发射器和接收器架构的建议。

This programme will lay the scientific foundations for a new generation of sensor systems that will be mounted in vehicles to enhance the safety and efficiency. The sensors, small enough to be mounted unobtrusively on vehicles, will allow high resolution images to be produced in real time, that can be read and interpreted by intelligent vehicle systems to determine appropriate actions in hazardous circumstances and to dynamically control the vehicle to reduce fuel consumption. Sharing the images, or the information obtained from them, with the infrastructure and with other vehicles, will also make it possible to enhance safety and efficiency collectively within whole cohorts of vehicles. Sensors based on this technology will impact on future integrated automotive transport systems, supporting an intelligent transport philosophy with efficient use of renewable energy sources, low carbon emissions and enhanced safety for all road users.The new sensors will exploit the technology of circuits and devices in the 0.3 THz to 1 THz frequency range. Although this range, falling in between the upper end of the radio spectrum and the lower end of the infra-red, is currently not widely used, the device and circuit technology will mature over the next decade. There are several potential advantages in the use of this frequency band, as opposed to the lower frequency microwave and mm-wave bands or the infra-red and optical bands. The antennas required in the low THz band are smaller than those in the microwave and mm-wave bands, in proportion to the wavelength. The image resolution achievable is improved. There are two reasons for this. Firstly, narrower beams can be produced while using reasonably small antennas, when the wavelength is so short (less than 1 mm). Secondly, the high bandwidths available when using such high frequencies make it possible to distinguish between more closely spaced features in the reflected signal. At the same time, waves in this band are not susceptible to complete obscuration by road dirt or precipitation, as infra-red and optical systems would be.Before and during this work, there will be a strong focus on vehicle system applications, with input from automotive industry experts, to identify the specific requirements of future vehicle systems.To generate the required images, low THz waves must be transmitted from the vehicle, propagate through the surrounding environment and be scattered from objects and surfaces. Scattered waves propagating back to the vehicle and received by the sensor antenna provide the information required to form an image. The main research work activities in this project all relate to these physical aspects of the imaging systems. Firstly, the properties of the road environment will be determined to find the specific frequency windows in which low THz signals can propagate through air, precipitation, vehicle exhaust gases, road spray and airborne particles such as dirt and grit. This will involve a combination of measurements in controlled, enclosed artificial environments created in the laboratory, and real road trials. Then, the scattering properties of typical road scenes and surfaces will be analysed to determine the most appropriate frequencies and waveforms to use for imaging. A major part of the research will involve the study of the antennas and beamforming networks that will be required to implement low THz imaging systems on vehicles. Working at the boundary between the radio frequency spectrum and the optical spectrum provides opportunities to exploit and merge transmitter concepts based on both lenses and antennas. The system requirements will be studied to arrive at recommendations for transmitter and receiver architectures that could be realised using the emerging circuit and device technologies.