10 MHz to 1.1 THz Vector Network Analyser

The low THz band of the electromagnetic spectrum covers frequencies from around 100 GHz to around 1 THz. In terms of wavelengths, this corresponds to 3 mm down to 0.3 mm, in between the radio and optical ranges. This creates a special set of application opportunities and engineering problems, making this band a specialism in its own right. At Birmingham University, we are already working on potential future applications of this band, including short range exceptionally broad bandwidth communications, tiny high resolution radar systems for moving platforms such as autonomous vehicles, novel sensors based on atomic and molecular quantum states, and artificial metamaterials that allow shielding from electromagnetic waves and new forms of antennas. In this project we are establishing an advanced measurement facility that will enable researchers to test and characterise novel low THz devices and systems. The vector network analyser measures scattering parameters throughout this band of interest.

Scattering parameters represent the transmission and reflection of THz waves through and from multiple port circuits and transmission media. They enable researchers to test their novel component designs precisely against the theoretical performance predicted by a simulator. This is very important in the low THz bands, because the sensitivity to random surface roughness and slight structural misalignment in electronic components is very high. Scattering parameter measurements also enable researchers to evaluate the electromagnetic properties of new materials, to test new forms of sensors and to characterise the transmission of electromagnetic waves through antennas and propagation media.

The measurement and use of scattering parameters at lower frequencies, in the microwave bands, is common practice, but in the low THz bands it requires highly specialised equipment to generate the high frequency oscillations with the required frequency and phase accuracy, by multiplying up the output frequency of a lower frequency vector network analyser (VNA) before transmission, and converting the resulting reflected or transmitted received THz signals back down to the lower frequency.

This project will involve procuring and setting up the VNA and multiplier/downconverter heads, and making this equipment available to researchers in Birmingham University and in the wider academic community and in industry, to encourage and facilitate research and development of systems and components designed to exploit a currently almost unused range of frequencies.

Continued growth is predicted in demand for the internet, including the emerging Internet of Things, in demand for high data rate communications and high resolution sensing systems. Exploitation of the THz frequency spectrum will contribute to meeting this demand, because THz communications offers very high bandwidth and THz sensors can provide high resolution images, even in bad weather or environmental conditions.

The availability of the equipment proposed here will impact strongly on UK (and European) Industry, and ultimately the customers and society that they serve. The impacts will be both direct, as industrial companies become users of the equipment on their own projects, and indirect, as the flow of innovative technologies based on increased academic research in THz technology, leads to new communication and sensing products. Examples include the potential industrially based beneficiaries that have provided letters of support, all anticipating future requirements for using the equipment at Birmingham, which are included in the attached documents

Jaguar Land Rover particularly note the importance of supporting THz technology in the UK, in the context of strong competition from EU automotive companies. They also point out the route by which adoption of new automotive sensing technology flows, from the luxury car market where it originates, to the volume market, spreading the societal benefits (eg in road safety, fuel efficiency and capacity) more widely.

NEC Europe Ltd point out the need for research in the low THz bands to serve growing demands for communications capacity, both in channel characterisation and component development. They envisage NEC and other members of the ETSI mWT ISG using the Birmingham facility and supporting others to do so for this purpose.

The National Physical Laboratory (NPL) is fully supportive of the bid, envisaging a significant increase in research activities in this field, and pointing out the benefits for the quality and impact of UK research.

QinetiQ points out the benefits in terms of UK competiveness in both commercial and military equipment.

The equipment will impact directly on the several existing research projects at Birmingham and will therefore enhance their impacts.

The TRAVEL grant (EP/L019078/1) has partners BAE Systems, Thales, JLR and two SME RF device manufacturers (L3-TRL Technology and Elite Antennas), and will strongly impact future automotive radar technology.
Micromachined Circuits for Terahertz Communications (EP/M016269/1) also has BAE Systems as a partner and a further three RF device manufacturers (Plextek, Farran Technology and Teratech Components). The latter grant, looking at the design, construction and testing of a communications system at 300 GHz, is also with Rutherford Appleton Laboratory and the Fraunhofer institute, Germany. Sponsors of the Quantum Hub include e2v, DSTL and Msquared Lasers. Particular applications for new communications devices are communication systems (naturally), radar and sensing scenarios, space and metrology. Successful micromachining of electronic circuits at frequencies over 300GHz has been demonstrated at The University of Birmingham. As an example, prototype hollow waveguide tube-based resonant cavities using a new interconnect principle to link Schottky diodes and transistors have been produced.
PATHCAD (EP/N012372/1), in which next generation 300GHz to 1THz radar sensors will be used as part of an intelligent imaging system, which will greatly benefit from use of the VNA, will impact strongly on the development of future autonomous vehicles and other platforms.