A system that incorporates teachings of the present disclosure may include, for example, a first solid electrode, a second electrode separated into subsections, and a dielectric medium separating the subsections from the first solid electrode, where the subsections of the second electrode include a first group of subsections and a second group of subsections, where the first group of subsections are connectable with a first terminal for receiving an input signal, and where the second group of subsections is connectable with a second terminal for providing an output signal. Other embodiments are disclosed.