Evaluation of CMUT Performance Under Different Excitation Signals and Electrode Coverage

CMUT output characteristics with different top electrode coverages were investigated by driving different excitation signals. Membrane displacements were obtained using a Simulink model. Membrane displacements were examined for three cases of electrode coverage, one-quarter, half and entire of the membrane area. The diameter and thickness of the CMUT membrane used in the simulation were 60 pm and 2.6 pm. First, the collapse voltages were found by using numerical calculations. Then these values were analyzed using the Simulink model. It was understood that electrode coverage affected the collapse voltage of CMUT. After that, analyzes were made for AC signals of different types (sawtooth, sine, and square) and different amplitudes DC bias voltages and AC excitation signals. Our results showed that CMUT has the highest displacement in the case of 100% electrode coverage when excited in square signal is used.