An apparatus in one example comprises a piezoelectric layer, an input transducer, an output transducer, and at least one electrode set. The input transducer is configured to convert an input signal from an input source to a surface acoustic wave and send the surface acoustic wave from an input portion of the piezoelectric layer to an output portion of the piezoelectric layer. The input transducer comprises a set of input passbands. The output transducer is configured to receive the surface acoustic wave from the output portion of the piezoelectric layer. The output transducer comprises a set of output passbands. The at least one electrode set is configured to apply at least one voltage bias to at least one portion of the piezoelectric layer to create an electric field that controls an acoustic velocity of the surface acoustic wave through the at least one portion of the piezoelectric layer. The at least one electrode set is configured to control one or more of the set of input passbands and the set of output passbands by adjustment of the at least one voltage bias.