Millimetre waves are suitable for a large range of aplications. In radar and imaging their shorter wavelength compared to microwaves offers higher resolution and greater bandwidth, as well as narrower beamwidths and physically smaller hardware. Millimetre waves are also better than terahertz (THz), the infrared and the visible parts of the spectrum at penetrating obscurants such as dust and cloud. They also have better penetration through tissue and many materials than optical wavelengths.

The high frequency also makes mm-waves attractive for communications systems due to the high bandwidths that can be obtained, and frequencies on the order of 30GHz are used for both terrestial and satellite communications.

The mm-wave regime is particularly useful for spectroscopy of materials, both in Fourier transform type systems and for very high frequency magnetic resonance studies, where the higher fields that accompany measurements at high frequencies offer improved spectral resolution and experimental sensitivity.

Another area which exploits mm-waves is plasma diagnostics, where techniques such as reflectometry, polarimetry and radiometry are used to reveal the properties of plasmas in nuclear fusion experiments. Very high power mm-wave sources such as gyrotrons are used to heat the plasma in fusion experiments.

Millimetre waves at St Andrews

At St Andrews, we use mm-waves for imagingradaratmospheric studies and electron paramagnetic resonance spectroscopy. More on our research may be found using the links at the top.