New resources section

New resources section for notes, examples and other material.

I have added a resources section section to the website, accessible from the navigation bar at the top, where I shall put notes and other material that others may find useful.

As a start, I have added some notes on small aperture theory that I made while implementing small aperture models in the Vulture FDTD code and the AEG power balance solver. These notes are a summary of the key steps in the theoretical development of the aperture polarisabilities and equivalent dipole moements. There is a wide variation in the conventions used in the literature for defining the polarisabilties making it remarkably easy to incur “factor of two/half” errors in the transmitted fields. These notes outline all the stages of the development starting from Maxwell’s equations using a consistent set of conventions in an endeavour to provide a correct implmentation.