10 MHz to 1.1 THz Vector Network Analyser

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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.