Terahertz Technology for Future Road Vehicles

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.

Ultimately the beneficiaries of this research will be all road users. The high resolution imaging systems made possible by the sensors which form the subject of this research will be deployed in road vehicles to enhance safety, for road users both inside and outside of the vehicle, and to improve the efficiency of vehicles, thereby reducing the effect of road traffic on the environment. These impacts will begin when the first systems come to market, probably in luxury vehicles initially, within about 5 years of the end of the project, and will grow as the technology penetrates into the mass market for vehicles, over about a 10 year period.

Vehicle manufacturers within the UK such as Jaguar LandRover will benefit from the opportunity to maintain their advantages in the commercial automotive market, by being amongst the first in the world to market these advanced systems.

Imaging systems based on low THz technology will also be of interest to manufacturers of military systems and unmanned vehicles, such as BAE Systems and Thales.

The work will benefit UK and EU policy makers who have a strategy to reduce dependance on the USA in this strategic technology area. Transport system researchers and policy makers would benefit from early indications of the capabilities of these imaging systems and their potential impact on future road infrastuctures for intelligent transport systems.

Researchers in THz active and passive component technologies will benefit from the research outcomes. The work described here will provide a pathway to what could be the first mass market application for low THz technology. As such, during this programme, the research will provide benchmarks for the assessment of the performance of such device technologies, in terms of basic link budget parameters such as transmitter power and phase noise, and receiver noise figures. Beyond the completion of this programme, the research will lead to a mass market application for such devices. Automotive systems typically have a very long gestation period, because of the need to establish safe, reliable operation subject to international standards, along with minimum manufacturing costs in high volume. Therefore a 10 year timescale might be expected for the development of this mass market. Existing UK companies and new spin-out companies specialising in the design and manufacture of mm-wave and THz circuit modules would benefit from the growth of this new market.

The researchers working on this project will gain valuable technical and professional experience from working in this important and rapidly developing area of technology, which could provide a springboard for longer term research and/or academic careers. The reputational benefit of the work will provide the investigators with opportunities to continue recruiting and training doctoral and masters level students. Masters level teaching informed by the outcomes of the research will further strengthen the University's reputation in this area.