32 results about "Piezoelectric coupling" patented technology

An acoustic resonator with improved quality factor and electro-mechanical coupling is disclosed. In one embodiment, the acoustic resonator includes an acoustic mirror formed on the top surface of a substrate or in the substrate, a first electrode having a end portion, formed on the acoustic mirror, a piezoelectric layer formed on the first electrode; and a second electrode formed on the piezoelectric layer, where at least one of the first electrode and the second electrode and the piezoelectric layer define a gap in a region that overlaps the end portion of the first electrode. In one embodiment, a dielectric film is deposited on the surface of the end portion of the first electrode to form completely planarized surface before the piezoelectric layer deposition. In another embodiment, a gap between the second electrode and the piezoelectric layer, so that the piezoelectric coupling in the end portion area of the first electrode is minimally contributed into the whole resonator.

The invention provides an accurate controllable non-contact test piece rotary magnetic field fatigue excitation and vibration test device. The device comprises a vibration damping insulation clamp, a vibration damper, a dynamic balance device, a vibration exciter, an electromagnetic piezoelectric coupling vibration sensor, a test station, a transmission device and an accurate control device. The excitation and vibration test device is suitable for rotary test pieces and especially suitable for vibration characteristic researches on a wind power blade, an engine, a turbine blade, a helicopter rotor and a tail rotor blade, the excitation and vibration test device can vividly simulate vibration fatigue states of rotary test pieces respectively under conditions of 360-DEG all directions, same rotating speed and different excitation forces, same excitation force and different rotating speeds, and different rotating speeds and different excitation forces, the excitation and vibration test device can monitor related vibration characteristic parameters such as the excitation force, the vibration displacement, the vibration speed and the vibration acceleration continuously, and the excitation and vibration test device is suitable for vibration fatigue characteristic analysis on stationary test pieces.

The invention discloses a ray pectoral fin-imitated piezoelectric coupling propulsive mechanism. The ray pectoral fin-imitated piezoelectric coupling propulsive mechanism comprises a crankshaft, guide rods, a swinging block, a piezoelectric compound fin, a fish body pedestal, a crankshaft support, a driving motor, a battery pack and a main control panel, wherein the crankshaft is arranged on the crankshaft support; the swinging block comprises a pin shaft and a swinging block support; the pin shaft is arranged on the swinging block support; the crankshaft support and the swinging block support are fixedly arranged on the fish body pedestal; one of the guide rods is arranged between one end of the swinging block and the crankshaft; the driving motor and the crankshaft are connected through a gear; the piezoelectric compound fin is arranged at the other end of the swinging block; the battery pack can provide a direct current power source; the main control panel is electrically connected with the piezoelectric compound fin; the crankshaft is a four-turn crankshaft; the guide rod is arranged on each turning shaft of the four-turn crankshaft. The ray pectoral fin-imitated piezoelectric coupling propulsive mechanism can reduce the structural size, the weight of the fish body, and can realize chordwise fluctuation propulsion.

The invention provides a multi-arm coupled collision piezoelectric energy collection device and is intended to solve the technical problem that an existing piezoelectric energy collection device has low energy collection efficiency; the multi-arm coupled collision piezoelectric energy collection device comprises an outer frame, piezoelectric vibrators, a first base, a simple pendulum structure, a first magnet and a second magnet; the piezoelectric vibrators at least include a first piezoelectric vibrator and a second piezoelectric vibrator, the bottom ends of the vibrators are fixed to the first base and may generate high mutual coupling upon resonance, the simple pendulum structure comprises a second base, a link, a rocker and a striker ball, the bottom end of the link is fixed to the second base, the top end of the link is movably connected with the upper end of the rocker, the striker ball is fixed to the lower end of the rocker, and the striker ball may collide with the free end of the first piezoelectric vibrator or second piezoelectric vibrator while rocking, the first base and the second base are fixed to the bottom of the outer frame, the side of the outer frame close to the simple pendulum structure is fixedly provided with the first magnet, and the top of the outer frame close to the piezoelectric vibrators is fixedly provided with the second magnet. The multi-arm coupled collision piezoelectric energy collection device has effectively improved energy collection efficiency.

The present invention provides a duplexer, comprising: a transmit filter, which is connected between a transmit end and an antenna end and includes a series resonator and a parallel resonator connected in a ladder form; and a receive filter, so The receiving filter is connected between the receiving end and the antenna end and includes a series resonator and a parallel resonator connected in a trapezoidal form, wherein the LWR resonator is connected on the series branch of the TX or RX or the LWR resonator is connected on the The parallel branch of TX or RX is connected to the ground terminal; this application introduces LWR resonators in the structural design of filters and duplexers and applies them to piezoelectric filters and duplexers to improve piezoelectric filters, The performance of the duplexer, by using the impedance characteristics of the LWR resonant frequency point, flexible frequency and the characteristics of piezoelectric coupling coefficient adjustment, use different combinations of frequencies and piezoelectric coupling coefficients to achieve the required impedance transformation at a specific frequency point. .

The invention discloses a method for preparing textured lead zirconate titanate ceramic, namely a method for preparing highly textured PZT piezoelectric ceramic with a (001) direction. The method for preparing the textured lead zirconate titanate ceramic comprises the following steps of: preparing a strontium titanate template with a laminated microstructure from strontium carbonate and titanium dioxide serving as raw materials by using a two-step molten salt method; adding the template into PZT powder, casting, tabletting and sintering to prepare a PZT block material with higher texturing, piezoelectric coefficient and electromechanical coupling coefficient; and adding the strontium titanate template in microscopic directed arrangement into the PZT ceramic, making the template have directivity in the PZT ceramic by using a casting method, and making the PZT ceramic grow directionally along the template direction to have a highly textured structure similar to a single-crystal structure. The piezoelectric ceramic has higher orientation degree, and has the piezoelectric property greatly improved in the aspects such as piezoelectric constant, piezoelectric coupling coefficient and the like compared with the common PZT.

A method for determining parameters of the equivalent circuit of a piezoelectric vibration generator includes fixing one end of piezoelectric vibration generator on vibration source, making the otherend, maintaining constant sinusoidal vibration acceleration amplitude a, and obtaining relation curve between output voltage and vibration frequency of piezoelectric vibration generator under different load resistances RL by sweeping frequency; determining the short-circuit resonant frequency fsc, the static capacitance Cmc, the mechanical quality factor QML, the maximum power value Popt, the resistance value RML, the short-circuit resonant voltage VML ([omega] sc); and calculating the equivalent inductance Lm, the equivalent capacitance Cm, the equivalent resistance Rm, the equivalent input stress VF, the piezoelectric coupling coefficient A and the static capacitance Cmc. The invention can accurately describe the relationship between the output voltage characteristic of the piezoelectricvibration generator and the load, the ambient vibration frequency and the acceleration, and the electric measuring instrument required for measuring is low in cost.

The present invention provides a duplexer, including: a transmitting filter connected between a transmitting end and an antenna end and including series resonators and parallel resonators connected in a trapezoidal form; and a receiving filter, the The receiving filter is connected between the receiving end and the antenna end, wherein, the transmitting end, the receiving end, the antenna end or the transmitting end and the receiving end respectively lead a branch to the ground end, and the LWR resonator and the passive device are connected in series In this branch; the application introduces the LWR resonator in the structural design of the filter and the duplexer to be applied in the structure of the piezoelectric filter and the duplexer to improve the performance of the piezoelectric filter and the duplexer, by Utilizing the impedance characteristics of the LWR resonant frequency point, flexible frequency and the characteristics of piezoelectric coupling coefficient adjustment, different combinations of frequency and piezoelectric coupling coefficient are used to achieve the required impedance transformation at a specific frequency point.