The velocity and attenuation of a surface acoustic wave on a piezoelectric semiconductor may be controlled by adjusting the bias of a reverse‐biased distributed diode. With the proper choice of resistivity and operating frequency, changes in velocity of 1% and attenuation of 300 dB/cm may be achieved inc‐axis cadmium sulfide for bias voltages under 30 V. Theoretical behavior is presented and initial experimental results are summarized.