Millimeter- and Submillimeter-Wave Applications in Biology: Potential and Challenges

Peter H. Siegel
California Institute of Technology

The millimeter and submillimeter wave regimes, roughly spanning 30-3000 GHz, have moved to the forefront of recent expansion and innovative use of the RF spectrum. Traditional motivations for working at millimeter wavelengths have tended to focus mainly on commercial and defense-motivated wireless applications, such as communications, radar and to some extent, imaging. At higher THz frequencies, despite considerable commercial pressure, most of the emphasis is still on basic science, with a strong concentration in fundamental physics and chemistry, spectroscopy, and ground and space-based astrophysics, planetary atmospheres, and Earth science. As we move from the “Space Age” into the “Age of Biology” it is appropriate to take a closer look at what we can already do with millimeter and submillimeter-wave technology, and whether we might turn up any interesting new applications, or at least find some low hanging fruit which might be easily plucked, by simply refocusing some existing circuits and techniques. On the way, there are essential tweaks that have to be made to common devices and circuits, particularly antennas, in order to accommodate the constraints of water-based tissue.