Internal mirrors for time-reversal optimisation

This study reports on the use of time-reversal techniques for the design and optimisation of microwave components. Loss of spatial resolution due to evanescent mode decay in the presence of finite machine precision restricts the scope for optimising large complex devices. This serious problem is addressed by introducing internal time-reversal mirrors for the first time. In conjunction with an explicit local modal decomposition, these mirrors ensure that the evanescent fields scattered from a component are correctly captured. Although equally applicable to any time-domain simulation technique, in this work the transmission-line modelling method is used to implement the necessary forward and reverse-time simulations.