Performance Parameters and Frequency Response of CMUTs in Transmit, Receive, and Pulse-Echo Operation

摘要: Models of electrostatic transducers that assume a constant shape function for the plate’s deflection facilitate derivation closed-form design expressions. This work analyses static and frequency-response characteristics capacitive micromachined ultrasonic (CMUTs) using shape-function based model. analysis shows across all CMUT designs given plate shape, CMUT’s parameters vary with bias voltage in same manner. Normalizing by pull-in gap height enables this result. The examined are deflection, capacitance, transformer ratio, spring softening, coupling coefficient. As shown here, assuming basic second-order model CMUT, these along resonance frequency quality factor describe response. specifically examines ideal parallel-plate clamped circular CMUTs, but it extends to other shapes substitution different expressions capacitance as deflection.