Embodiments of the invention include a waveguide structure that includes a first piezoelectric transducer that is positioned in proximity to a first end of a cavity of an organic substrate. The first piezoelectric transducer receives an input electrical signal and generates an acoustic wave to be transmitted with a transmission medium. A second piezoelectric transducer is positioned in proximity to a second end of the cavity. The second piezoelectric transducer receives the acoustic wave from the transmission medium and generates an output electrical signal.