Queensland company Mesaplexx is using the Australian Synchrotron to develop the next generation of microwave filters for improved mobile phone signal quality and data bandwidth.
The ceramic filters are used in microwave communications systems by telecommunications manufacturers such as Nokia, which incorporates hardware components from other manufacturers into its own-branded products. Mesaplexx's first microwave filter is currently being trialled by several telecommunications manufacturers.
The properties of the ceramics used in these microwave filters depend on manufacturing conditions, so one approach to product development would be to vary the manufacturing conditions to create lots of slightly different ceramics.
In such a competitive field, however, quick results are essential. That's why Mesaplexx materials scientist Toru Yamashita and Mesaplexx consultant solid-state scientist John Barry recently visited the Australian Synchrotron to use x-ray absorption fine structure (XAFS) on the x-ray absorption spectroscopy beamline. XAFS will enable them to gain a more detailed understanding of how the localised atomic structure of the ceramics, particularly the titanium-oxygen bonds, responds to changes in manufacturing conditions - and provide valuable clues about how to produce better ceramics. Standard laboratory x-ray diffraction techniques don't pick up the subtle changes that they are interested in, such as the way the titanium-oxygen bonds respond to the introduction of small quantities of other metal ions.
Mesaplexx had previously used the powder diffraction beamline at the Australian Synchrotron to determine the 'unit cell' - the primary building block - of the polycrystalline ceramic structure. Although the question of which ceramic structures work best as microwave filters is yet to be answered in full, materials with a 'superlattice' (an extra degree of symmetry) are know to perform better than those without. The synchrotron results showed that the superlattice was mainly located along one axis of the crystal structure.
The synchrotron findings will be combined with other test results and computer models to provide insights into the relationship between ceramic structure and performance.
Improved microwave filters could be used to boost data transfer speeds and improve reliability in existing telecommunications networks in Europe, for example, reducing the number of voice calls that drop out due to system congestion. The filters could also be used to increase the range of new base stations being established for wireless communications in markets such as China and India.
"The Australian Synchrotron is very impressive," John said. "It's equal to any overseas user facility, it's much better organised than some, and the equipment is top rate."
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Queensland company Mesaplexx is using synchrotron techniques to develop the next generation of microwave filters. |