P2P-4 Calculation of Transformer Ratio in Mason´s Equivalent Circuit for cMUTs

We present a new method to calculate the transformer ratio of a cMUT in Mason´s equivalent circuit model. The effect of the spring softening capacitance is also included in the analysis. We use the existing turns ratio calculation methods as a starting point to calculate the force-voltage ratio at the secondary of the transformer and the input port of the circuit. We use this ratio and the capacitances in the Mason´s circuit to find the actual turns ratio. Different methods are discussed for the calculation of the equivalent circuit parameters. We show that the transformer ratio has a bounded maximum at collapse voltage. We also investigate the effect of electrode size on the transformer ratio. Transformer ratio decreases with decreasing electrode size