The influence of fringing electric fields at the edges of the Capacitance Micromachined Ultrasonic Transducer’s (CMUT’s) gap and insulation layers are included into the parallel plate capacitance phenomenon. Its effect on various CMUT parameters are derived and compared to Finite Element Analysis (FEA) predictions. This gives rise to excess capacitances. A correction factor due to the finiteness of the electrode’s diameter in nanostructure devices is introduced for accurate prediction. Inclusion of an insulation layer helps in improving the performance of the ultrasonic transducer in comparison to a structure devoid of it. Analytical modelling of the structure as ultrasound transmitter consisting of 110 µm diameter membrane arrays exhibits a resonance of 1.65 MHz, which closely matches with published experimental data is carried out. CMUT with Si₃N₄ as insulation layer has higher device capacitance, increased membrane displacement, higher coupling factor, and lower collapse voltage as compared to a structure without insulation at the same bias, structural dimensions, and material properties. The characteristics exhibited by the insulated structure are advantageous as a transducer. All the results are compared with FEA where excellent agreement is observed.

电容微加工超声换能器（CMUT）的间隙和绝缘层边缘的边缘电场的影响被包括在平行板电容现象中。得出其对各种CMUT参数的影响，并将其与有限元分析（FEA）预测进行比较。这产生了多余的电容。为了精确预测，引入了由于纳米结构器件中电极直径的有限性而产生的校正因子。与没有绝缘层的结构相比，包含绝缘层有助于改善超声换能器的性能。超声发射器由直径为110 µm的膜阵列组成的结构的分析模型表现出1.65 MHz的共振，与已发表的实验数据非常吻合。含硅的CMUT与具有相同偏压，结构尺寸和材料特性的无绝缘结构相比，作为绝缘层的₃ N ₄具有更高的器件电容，更大的膜位移，更高的耦合系数和更低的崩溃电压。绝缘结构表现出的特性作为换能器是有利的。将所有结果与观察到极佳一致性的FEA进行比较。