Changde He

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A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V) characteristic curve shows that the(More)
An ultrasonic transducer is a key component to achieve ultrasonic imaging. This paper designs a new type of Microelectromechanical Systems (MEMS) based capacitive ultrasonic transducer and a linear array based on the transducer. Through directivity analysis, it can be found that its directivity is weak due to the small size of the designed transducer, but(More)
A 1 × 16 capacitive micro-machined ultrasonic transducer linear array was designed, fabricated, and tested for underwater imaging in the low frequency range. The linear array was fabricated using Si-SOI bonding techniques. Underwater transmission performance was tested in a water tank, and the array has a resonant frequency of 700 kHz, with pressure(More)
A fast integrated gate driver with amorphous silicon thin film transistor (a-Si:H TFT) is proposed in this paper. To improve the circuit speed, a new input scheme is designed to provide a full scale pre-charge voltage. So the loss of pre-charge voltage, a challenge in the conventional designs, is avoided. Simulations show that the proposed gate driver has a(More)
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