In one general aspect, an apparatus can include a shield dielectric disposed within a trench aligned along an axis within an epitaxial layer of a semiconductor, and a shield electrode disposed within the shield dielectric and aligned along the axis. However, upon confinement into the cylindrical pores, of average diameter 20 nm, of a porous membrane such features of microphase separation do not occur. The plate stack can include two plates which are connected at their longitudinal edges to form a flat tube which contains a turbulator through which exhaust gas flows. By implementing a filter at the corresponding frequency, data having that frequency will be transmitted.