Galliumnitride-based Gunn Diodes for active imaging scanners
In many applications in the field of sensor and imaging technologies small Terahertz (THz)-radiation sources are required to emit stable in frequency narrowband electromagnetic radiation. For the envisaged frequency range between 100 GHz to 700 GHz there are presently no cost-effective, compact and narrow-band THz sources with high output power available.
The THz sources based on the new GaN Gunn Diodes will fill this gap and help the THz-radiation to become a breakthrough technology especially for the following spectroscopic and imaging applications:
Non-destructive material testing
Similar to ultrasonic radiation the THz radiation is reflected on boundary layers and therefore allows, for example, to determine delamination in integrated circuits as well as quality control of weld seams. Due to the high THz output level of the GaN Gunn Diode of this research group it becomes possible to detect hidden and deep lying structural damages. A particularly promising field of application is the usage of the GaN Gunn Diode for quality control of plastic and composite materials. There it will become possible to control weld seams as well as detect inclusions and cavities.
The Gunn diode’s high output level allows direct inline-quality control, for example on plastic materials, also in high throughput processes. Also many other important industrial processes, for example the proper filling of packages can be controlled directly with the GaN Gunn Diode in the production line.
THz scanners for medical applications
In medicine THz radiation can be used to detect changes of the H2O concentration in human tissue. By this, healthy tissue can be differentiated from diseased tissue.
Food quality control
The combination multiple GaN Gunn Diodes for different frequencies allows to determine spectral information for freshness-control of packaged food (e.g. meat).
Gas and molecular sensors
Polar molecules show characteristic absorption spectra in the THz area. By means of combination of multiple Gunn Diodes, which are exactly tuned to the absorption maxima of selected molecules, cost-effective detectors for selected critical substances (e.g. gases, drugs, biomolecules) can be provided.
Within the Pioneer Fund Project an important step towards a marketable THz-source based on GaN Gunn Diodes will be made. A prototype with integrated antenna will be aimed at to increase the interest of companies and investors to facilitate further funding from industry and turn this technology into a marketable product.