Patent ID: 9586233
Date: 2017-03-07
CPC Classifications: B06B

Claim:
1. A capacitive micromachined ultrasonic transducer (CMUT), comprising: a. a substrate; b. a bottom conductive layer, wherein said bottom conductive layer is disposed on a bottom surface of said substrate; c. a cavity, wherein said cavity is disposed into a top surface of said substrate; d. a nonconductive layer, wherein said non-conductive layer is disposed on said substrate top surface and on said cavity; e. a CMUT plate, wherein said CMUT plate is disposed on said nonconductive layer and across said cavity; f. a top conductive layer, wherein said top conductive layer is disposed on a top surface of said CMUT plate; g. a pressure control via, wherein said pressure control via spans from said cavity to a bottom surface of said bottom conductive layer; and h. an active pressure controller, wherein said active pressure controller is connected to said pressure control via, wherein said active pressure controller is capable of actively varying a pressure differential across said CMUT plate according to an ambient pressure, wherein said pressure differential is from 1.01 bar to 20 bar, wherein said CMUT is configured to form a mechanical resonance of said CMUT plate and an acoustic Helmholtz resonance with said cavity and said via, wherein said CMUT plate resonance is a dominant mode at said 1.01 bar ambient pressure, where said CMUT plate resonance becomes weaker while said Helmholtz resonance dominated mode becomes stronger as said active pressure controller increases to said 20 bar ambient pressure.