The present invention relates to a circuit for processing radio frequency signals. The resonant circuit includes a substrate. The substrate can be a meta material and can incorporate at least one substrate layer. A resonant line and at least one ground can be coupled to the substrate. An end of the resonant line can electrically shorted to the ground or electrically open with respect to ground. The substrate layer can include a first region with a first set of substrate properties and at least a second region with a second set of substrate properties. At least a portion of the resonant line can be coupled to the second region. The first and/or second set of substrate properties can be differentially modified to vary a permittivity and/or a permeability over a selected region. A third region can be provided with a third set of substrate properties as well.