In order to efficiently model electromagnetic propagation in large complex environments, power balance methods can be used. The objective of this project is to develop new aspects of the power balance model to allow it to give improved results in a number of scenarios such as:
- radio propagation in buildings and vehicles for communications and wireless sensor networks;
- coupling of Electromagnetic Interference (EMI) into equipment.
A student undertaking this project would be expected to develop new power balance methods, validate the results using other simulation methods and by measurement, and incorporate the methods in our existing Matlab based modelling tools.
More about power balance:
The origins of the Power Balance (PWB) approach are in the work of Hill et. al. in a paper that showed how to divide the power loss in a cavity into four component parts: power lost through apertures; power absorbed by receiving antennas in the cavity; power absorbed in lossy objects and power absorbed in the cavity walls (Hill et al. 1994). Further theoretical work was carried out at NIST and the method was developed into a systematic simulation technique overlaid on the Electromagnetic Topology (EMT) methodology by Parmantier and Junqua at ONERA (Junqua et al. 2005; Parmantier & Junqua 2007). The PWB code developed at ONERA treats the problem space as a topological model of shielded cavities, coupled with wires, apertures, antennas etc. Each of these is assigned a model for its coupling cross section, and the power transferred and the resulting power density in each cavity is calculated over a broadband range using BLT solver. A very similar approach has recently being reported in (Tait et al. 2011). At York we have developed an in-house circuit based PWB solver implemented in MATLAB. One of the limitations of the power balance method is that it does not consider the shadowing effect of objects and we wish to explore ways of solving this problem, our recent work suggest diffusion based models may be suitable (Flintoft et al 2016 and Yan et al 2018).
Yan, J, Dawson, J. & Marvin, A., "Estimating reverberant electromagnetic fields in populated enclosures by using the diffusion model" , Electromagnetic Compatibility (EMC), 2018 IEEE International Symposium on , 363-367 , July 30 - August 3, 2018 , DOI: 10.1109/EMCSI.2018.8495445 , Available: http://eprints.whiterose.ac.uk/130846/
Flintoft, I. D., Marvin, A. C., Funn, F. I., Dawson, L., Zhang, X., Robinson, M. P. & Dawson, J. F. , "Evaluation of the Diffusion Equation for Modelling Reverberant Electromagnetic Fields" , Electromagnetic Compatibilty, IEEE Transactions on , vol. 59, no. 3 , 760-769 , June, 2017 , DOI: 10.1109/TEMC.2016.2623356 , Available: http://eprints.whiterose.ac.uk/106570/ Junqua, I., Parmantier, J.-P. & Issac, F., 2005. A network formulation of the power balance method for high-frequency coupling. Electromagnetics, 25(7-8), pp.603–622.
Hill, D.A. et al., 1994. Aperture excitation of electrically large, lossy cavities. IEEE Transactions on Electromagnetic Compatibility, 36(3), pp.169–178.
Junqua, I., Parmantier, J.-P. & Issac, F., 2005. A network formulation of the power balance method for high-frequency coupling. Electromagnetics, 25(7-8), pp.603–622.