Tube-type double-parabolic-reflector ultrasonic transducer (T-DPLUS)

Theory of a Double-diaphragm Mems Ultrasonic Transducer

Conventional capacitive MEMS transducer designs feature a single flexible diaphragm acting as a moving plate and an electrode patterned on the substrate acting as a stationary plate. Such devices generally function adequately as receivers. However, such devices show poor transmission efficiency when the gap dimension is limited by the manufacturing process and when the diaphragm would suffer “p...

Horn-Type Piezoelectric Ultrasonic Transducer: Modelling and Applications

UWB Spiral Antenna with Parabolic Reflector

A cavity-backed spiral antenna with ultra-wide band width is presented. By using a parabolic reflector, the radiation of the antenna becomes uni-directional, and the gain is promoted. The antenna is fed by a coaxial cut-away balun with fan-shaped patch which keeps a wideband impedance matching. The simulated bandwidth for VSWR < 2 covers 0.36 ~ 6.83GHz or bandwidth ratio of 19:1, and the gain a...

Design and Fabrication of a Longitudinal-Torsional Ultrasonic Transducer

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...

Design and Fabrication of a Longitudinal-Torsional Ultrasonic Transducer

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...