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Professor Christopher Railton

Professor Chris Railton received his PhD degree in ‘Boxed Microstrip Circuits’ from the University of Bath in 1984, and then joined the University of Bristol. In 1999, he was appointed Professor in Computational Electromagnetics.

His research interests are focussed  on the development of novel and efficient algorithms for a wide variety of electromagnetic modelling scenarios . Professor Railton’s main area of activity is in extending the Finite Difference Time Domain (FDTD) method  to allow larger and more complex problems to be solved using readily available computer power. In addition, he has worked on other techniques including the Spectral Domain Method, the Partial Element Equivalent Circuit (PEEC) method and the Transmission Line Matrix (TLM) method. Much of his research has involved combining different methods in order to exploit the best properties of each.

Significant research achievements include:
The improvement of the FDTD method by the incorporation of Static Field Solutions in order to account for metal edges without the requirement for large computer resources. This novel work has led to a number of publications in which, for the first time, it has been possible to demonstrate a numerically stable and accurate edge correction algorithm for the FDTD method which ais applicable to practical applications. Despite considerable effort from a number of international research groups,  the problem of efficiently treating curved structures in the Cartesian mesh of the FDTD method has not been completely solved. The methods which had been put forward by renowned  international experts had an unrecognised but fundamental flaw that caused late time instability. Professor Railton’s work  has recently successfully resolved this  problem  and provided many new research opportunities as a result.

An alternate approach to dealing with difficult structures has more recently produced excellent results. This techniques uses Modified Assigned Material Parameters (MAMPs) which are calculated prior to the FDTD computationrun so that the overhead penalty is very low. This novel technique has already led to the publication of several international journal papers and has been demonstrated for a range of applications ranging from complex planar antennas to the calculation of the Earth’s currents resulting from lightning strikes.Investigations into ways of combining FDTD and PEEC methods to achieve the benefits of both methods without the drawbacks has recently produced results with the development of a proposed novel method. The research has led to a number of publications and attracted great interest and positive comment from eminent researchers in the USA and Europe.

A decomposition technique for FDTD involving Huygens equivalent surfaces is being developed which is expected to facilitate the analysis of large complex antenna arrays that cannot be modelled in any other practical way. Preliminary results are extremely encouraging and the aim is to apply the method to antenna array for breast cancer detection and high-speed data transfer in a complex environment.

The work of Professor Railton and his team on electromagnetics is widely used, and underpins, the research of other groups in the Centre eg. Photonics, and that of the Communications Systems & Networks Group work on antennas and breast cancer detection.

View a Selection of Professor Chris Railton's publications

Research keywords

  • electromagnetics
  • Microstrip Circuits
  • algorithms