Subsea radiowave propagation
The frequency dependent attenuation of radiowave propagation in seawater has traditionally restricted undersea radio wave communication to very low carrier frequencies or very short link distances. Recently the proposal to adapt modern wireless communication and networking technology to the underwater environment has generated renewed interest in short range radiowave links. Accurate knowledge of the propagation characteristics, in particular attenuation and phase velocity, or alternatively the sea water media's conductivity and permittivity, is essential for accurate radiowave link analysis and design. This project will investigate the dependence of sea water conductivity and permittivity on frequency, salinity, temperature and electric field strength, and examine the consequences for radiowave link design. This will require an in-depth study of the relationship between the chemistry of aqueous solutions and their effective electrical parameters. An essential aspect of this project is experimental validation of theoretical and electromagnetic simulation predictions.
Expected Background knowledge and skills:
- Good theoretical understanding of electromagnetic and microwave engineering.
- Good programming skills and experience with one or more computational tools (Matlab, C, Fortran, etc).
- Experience with commercial circuit and full wave simulation tools desirable.
Description of work:
- Study the fundamental behaviour of salt water chemistry to gain a deep level understanding of the electromagnetic properties of salt water solutions.
- Develop laboratory based simulation and measurement methods for characterising the electrical properties of salt water solutions.
- Apply this knowledge of the salt water's electrical behaviour to design radiowave links that exploit the dispersive media properties to achieve desirable link performance.
- Devise and conduct open-water experiments to validate analytical predictions of radio path behaviour.