The kinetic energy of electrons in conductors of all types is generally neglected when computing the intrinsic impedance of structures and devices. Except at very high frequencies this is a good approximation. In superconductors the kinetic energy contributes a strong kinetic inductance contribution to the impedance. We report use of the kinetic inductance to both generate and detect ultrafast voltage transients in superconducting device structures. Superconducting micro-bridge structures are fabricated from Tl <sub>2</sub>Ba<sub>2</sub>CaCu<sub>2</sub>O<sub>10</sub> thin films which are then used to demonstrate ultrafast voltage sampling. A simple model for sampling is explained in terms of hot electron dynamics in the presence of a superconducting energy gap.
We have conducted numerical and experimental studies of a simple metamaterial structure formed from 'C' shaped copper rings. Our study focuses on the investigation of the individual resonant elements by surface current and Q factor. We have also analysed wavelike signal propagation along these structures' axes recently predicted theoretically - so called magneto-inductive waves (MIWs). Computer based finite difference electromagnetic methods have been employed to both visualize the surface currents and investigate the effects of varying coupling within the structures. Experimental work has closely followed the theoretical work with measurements carried out using a Vector Network Analyzer to determine the frequency dependent scattering parameters. Applications of these structures are also considered in our work and the aim is to develop a robust, reliable design tool that enables rapid determination of the appropriate dimensions to enable operation of a magneto-inductive waveguide at a desired frequency. The simulation work demonstrates the possibilities for wave propagation in curved guides formed from stacks and rows of elements. And these may form the basis for a new class of microwave filter offering tunability and flexibility and requiring no direct connections to the driving circuits.