In one implementation, a matching network is provided comprising a pair of input terminals; a pair of output terminals; and at least two reactive components disposed between the pair of input terminals and the pair of output terminals. At least one of the reactive components comprises a coupled-inductor. In various implementations, the second reactive component can be a capacitor, and the capacitor can be at least partially realized using the parasitic capacitances of the environment. The matching network may be disposed in a capacitive wireless power transfer (WPT) system. In other implementations, inductors and coupled-inductors are further provided. In some implementations, for example, an inductor, such as but not limited to a coupled-inductor, may comprise a toroidal or semi-toroidal core comprising foil wire interleaved without notches.