202 results about "Acoustic filters" patented technology

Various patient monitoring systems, devices, and methods are disclosed for monitoring physiological parameters of a patient. A noninvasive blood pressure monitor can include an inflatable cuff, a pressure transducer, an air pump, and a plurality of air paths connecting the inflatable cuff, the pressure transducer, and the air pump. The monitor can also include an acoustic filter provided along at least one of the air paths. In some cases, the monitor can include first and second air pumps, as well as a processor to independently control operating characteristics of the air pumps. The processor can also control the air pumps so as to provide a first inflation rate for the inflatable cuff during a non-measurement portion of an inflation phase and a second, higher inflation rate during a measurement portion of the inflation phase.

An incubator can include a body, a bed supported by the body, and a canopy defining an interior chamber that includes the bed. The incubator can include any combination of various features configured to reduce sound energy inside the incubator. The incubator can include a passive radiator, a Helmholtz resonator, a meta material absorber, an active noise cancelation system, a vented door latch assembly, an acoustically permeable seal, a pressure relief valve, a lift mechanism that uses a belt drive, double paned canopy walls, a bin with insulating compliant elements, a manual pressure release valve, a pressure differential notification system, non-parallel or curved canopy walls, a mattress with reticulated foam, and / or an acoustic filter.

Various embodiments of an ear-wearable electronic device are disclosed. The device includes a housing having a top shell and a bottom shell, a microphone disposed within the housing, and an acoustic path disposed at least partially within the housing and extending between an acoustic port disposed at an outer surface of the housing and an outlet disposed within the housing that acoustically couples the acoustic path to an inlet of the microphone. The device further includes an acoustic filter disposed at least partially within an inner surface of the top shell and includes a neck and a resonance cavity acoustically coupled to the neck. The acoustic filter is acoustically coupled to the acoustic path via the neck. Further, the acoustic filter is configured to reduce an intensity of acoustic waves sensed by the microphone in a first frequency range.

The invention relates to a radial frequency-doubled sound filtering metamaterial and a topological optimization design method thereof.The radial frequency-doubled sound filtering metamaterial comprises scatterers which are arranged on a base body and distributed in a concentric circle mode, and the topological optimization design method comprises the following steps that a two-dimensional axial symmetry model is established, the two-dimensional axisymmetric model corresponds to the cross section of the radial frequency-doubled sound filtering metamaterial in the radius direction and comprises periodically arranged unit structures, and each unit structure comprises a main board and a square design domain; a Floquet periodic boundary condition is applied to parallel boundaries of a unit structure in the radius direction, other boundaries are set as free boundaries, a genetic algorithm is adopted to carry out iterative optimization on the material distribution topology of a square design domain, the optimal material distribution topology of the square design domain is obtained, and then the final optimized shape of the radial double-frequency sound filtering metamaterial is obtained. Compared with the prior art, the invention has the advantages of capability of realizing omni-directional sound wave frequency doubling filtering, high design reliability and the like.

A protection circuit for an acoustic filter and / or a power amplifier is disclosed. In one aspect, the protection circuit includes a bidirectional coupler that helps secure a measurement of power at an antenna. The power measurement is compared to a threshold by a detector, and if the power measurement is above the threshold, a signal is sent that causes debiasing of a power amplifier stage, which reduces power levels of signals being amplified by the power amplifier stage and correspondingly lowers the power level going through a filter associated with the power amplifier stage. By lowering the power level going through the power amplifier stage and the filter, both elements are protected against over power conditions allowing functionality to be maintained.

An acoustic control apparatus includes a processor with hardware. The processor calculates a first relational expression between acoustic filter coefficients of acoustic filters to be applied to voice signals containing information of sounds played back by two or more sound sources, based on an amplification magnification in a sound amplification control point with respect to the sounds played back by the two or more sound sources, and on transfer functions between the sound amplification control point and the two or more sound sources. The processor calculates a second relational expression between the acoustic filter coefficients, based on information of a frequency of the voice signals, and on an interval between the two or more sound sources. The processor calculates the acoustic filter coefficients based on the first relational expression and the second relational expression.

An acoustic device includes circuit elements, such as analog circuit components, between the first and second substrate and coupled to an acoustic resonator to form an acoustic filter within the acoustic device. In some examples, forming the circuit elements between the first substrate and the second substrate includes forming the first circuit elements in insulating material on the second substrate before coupling the second substrate to a first side of the first substrate. The circuit elements disposed between the first and second substrates may include capacitors, inductors, and electrical interconnects coupled to the acoustic resonator on the first substrate. Additional features may be included in the insulating material. The acoustic device avoids the need for bulky analog components coupled to the acoustic resonator via long interconnects through a package substrate, making it possible to reduce an acoustic device's package size.

A substrate that includes an encapsulation layer, a first acoustic resonator, a second acoustic resonator, at least one first dielectric layer, a plurality of first interconnects, at least one second dielectric layer, and a plurality of second interconnects. The first acoustic resonator is located in the encapsulation layer. The first acoustic resonator includes a first piezoelectric substrate comprising a first thickness. The second acoustic is located in the encapsulation layer. The second acoustic resonator includes a second piezoelectric substrate comprising a second thickness that is different than the first thickness. The at least one first dielectric layer is coupled to a first surface of the encapsulation layer. The plurality of first interconnects is coupled to the first surface of the encapsulation layer. The plurality of first interconnects is located at least in the at least one first dielectric layer.

Aspects of this disclosure relate to a multiplexer with an acoustic assisted trap circuit. The multiplexer includes an acoustic wave filter with an acoustic wave resonator and an impedance network that together provide a trap for a harmonic associated with another acoustic wave filter of the multiplexer. The acoustic wave filter can have an edge of a passband that is farther from the harmonic than other acoustic filters of the multiplexer.

The invention relates to a double-frequency filtering metasurface design method based on topological optimization. The method comprises the following steps: establishing a two-dimensional simulation model comprising a double-frequency filtering metasurface matrix and a scatterer; according to a preset target forbidden band, taking a forbidden band frequency covering frequency doubling target interval as a fitness function, coding the binary matrix representing material distribution as a chromosome to perform optimization iteration of the chromosome, and obtaining the chromosome with the maximum fitness function value; in optimization iteration, material distribution corresponding to chromosomes is constructed on a two-dimensional simulation model, an energy band structure of the two-dimensional simulation model is obtained, and a fitness function value is calculated; and according to the binary matrix of the chromosome with the maximum fitness function value, outputting final optimized material distribution of the double-frequency filtering metasurface, and performing performance verification on a result through simulation to obtain the double-frequency filtering metasurface of which a fundamental frequency wave can be blocked through a double-frequency wave. Compared with the prior art, systematic optimization of the frequency doubled sound filtering scene is realized.

Embodiments of this application provide a bulk acoustic resonator, an acoustic filter, and an electronic device, to improve performance of the acoustic filter. The bulk acoustic resonator includes a piezoelectric material layer, an interdigital transducer, and a dielectric layer. The interdigital transducer is disposed on the piezoelectric material layer. The interdigital transducer includes a first busbar and a second busbar that are disposed opposite to each other, a plurality of first electrodes, and a plurality of second electrodes. The plurality of first electrodes sequentially protrude from the first busbar to the second busbar along an extension direction of the first busbar. The plurality of second electrodes sequentially protrude from the second busbar to the first busbar along an extension direction of the second busbar. The plurality of first electrodes and the plurality of second electrodes are sequentially arranged in a staggered manner between the first busbar and the second busbar.

A micro-acoustic filter includes a piezoelectric layer having a crystalline structure that may be laterally excited in a plate mode. The piezoelectric layer is formed on a layer stack that reflects acoustic energy back toward the piezoelectric layer. Acoustic waves are excited in the piezoelectric layer by voltages provided in interdigital transducers (IDTs) on an exposed surface of the piezoelectric layer. The electrode fingers of the IDTs are spaced from the exposed surface rather than being in contact with the exposed surface of the piezoelectric layer to avoid losses and spurious modes. In some examples, the electrode fingers may be supported on one end in a cantilevered configuration to maintain a first distance from the exposed surface of the piezoelectric layer. In some examples, the electrode fingers may also be supported on a second end by a pillar extending the first distance to the exposed surface.

An apparatus for filtering is disclosed that implements an electrode structure with corrosion resistance and power durability. In an example aspect, the apparatus includes an acoustic filter with a piezoelectric layer and the electrode structure. The electrode structure is formed by a metal layer comprising copper and silicon and by an adhesion layer. The adhesion layer is deposited between the metal layer and the piezoelectric layer.

Filters and methods of making filters are disclosed. A filter device includes a substrate, a piezoelectric plate, and an acoustic Bragg reflector between a surface of the substrate and a back surface of the piezoelectric plate. A first portion of the piezoelectric plate has a first thickness, and a second portion of the piezoelectric plate has a second thickness less than the first thickness. A conductor pattern on front surfaces of the first and second portions of the piezoelectric plate includes a first interdigital transducer (IDT) with interleaved fingers on the first portion, and a second IDT with interleaved fingers on the second portion.

Filter devices and fabrication methods are disclosed. A filter device includes a piezoelectric plate and a conductor pattern on a front surface of the piezoelectric plate. The conductor pattern includes interdigital transducers (IDTs) of a plurality of transversely-excited film bulk acoustic resonators (XBARs) and a plurality of conductors connecting the plurality of XBARs in a ladder filter circuit architecture. The plurality of conductors includes a first conductor adjacent to a second conductor. An opening is provided through the piezoelectric plate between the first conductor and the second conductor.

A multi-band acoustic multiplexer filter circuit is provided. The multi-band acoustic multiplexer filter circuit includes multiple single-band acoustic filters and a multi-band filter circuit that can pass a signal in multiple passbands. In embodiments disclosed herein, the single-band acoustic filters and the multi-band filter circuit can be configured to collectively attenuate the signal in some of the passbands to thereby prevent the signal from becoming a blocking signal to any other passbands (e.g., adjacent passbands). By employing the multi-band filter circuit to provide a portion of the required attenuation to the blocking signal, each of the single-band acoustic filters can be subject to more relaxed attenuation requirements, thus making it possible to reduce complexity of the single-band acoustic filters and improve overall band rejection performance of the multi-band acoustic multiplexer filter circuit.

An apparatus for implementing a microacoustic filter having an acoustically decoupled electrode structure is disclosed. In an example aspect, a device includes a microacoustic filter having a piezoelectric layer (126), a substrate (316), and an electrode structure (308-1, 308-2, 308-3, 308-4). The piezoelectric layer has a crystal structure for a lateral excitation plate mode. The electrode structure is positioned between the piezoelectric layer and the substrate and has a first surface (504-1) facing the piezoelectric layer. The microacoustic filter also includes at least one spacer (136-1, 136-2) extending from the substrate through a plane (508) defined by the first surface of the electrode structure and toward the piezoelectric layer to form a cavity (318) between the electrode structure and the piezoelectric layer.

Embodiments of this application provide an acoustic filter, a production method therefor, and an electronic device, to relieve impact of a transverse mode excited in an acoustic resonator. The acoustic filter includes a piezoelectric substrate and an interdigital transducer located on a side of the piezoelectric substrate. The interdigital transducer includes a first bus bar and a second bus bar. An edge region, a gap region, a central region, and a slant region that are arranged in a first direction are included between the first bus bar and the second bus bar. Parts that are of a first electrode finger and that are located in the edge region, the gap region, and the central region are parallel to the first direction, and a part that is of the first electrode finger and that is located in the slant region is slanted relative to both the first direction and a second direction. A sound speed of an excited surface acoustic wave at the part that is of the first electrode finger and that is located in the slant region is reduced, so that the part forms a waveguide, to adjust charge distribution of an interdigital electrode and suppress excitation of the transverse mode. Based on the foregoing disposal, only extension directions of parts of the first electrode fingers need to be adjusted. This helps reduce an area occupied by a resonator.

A micro-acoustic filter includes a piezoelectric layer (408) having a crystalline structure that may be laterally excited in a plate mode. The piezoelectric layer is formed on a layer stack (410) that reflects acoustic energy back toward the piezoelectric layer. Acoustic waves are excited in the piezoelectric layer by voltages provided in interdigital transducers, IDTs, on an exposed surface (406) of the piezoelectric layer. The electrode fingers (404A, 404B) of the IDTs are spaced (414) from the exposed surface rather than being in contact with the exposed surface of the piezoelectric layer to avoid losses and spurious modes. In some examples, the electrode fingers may be supported on one end (420) in a cantilevered configuration to maintain a first distance from the exposed surface of the piezoelectric layer. In some examples, the electrode fingers may also be supported on a second end by a pillar extending the first distance to the exposed surface.

A micro-acoustic RF filter comprises first and second ports (101, 102). First and a second signal paths (120, 110) are coupled between the first and second ports and include a corresponding resonator (111, 121). The resonator of at least one of the signal paths is a micro-acoustic resonator. One of the signal paths includes also a phase shifter (232) serially connected with the resonator (111). The micro-acoustic RF filter achieves a broad passband determined by the resonance frequencies of the micro-acoustic resonators. The filter allows flexible adaption of the passband and stopband performance.

The invention provides an elastic wave resonator and a communication device thereof, the elastic wave resonator comprises an interdigital electrode, a piezoelectric film, a suspension electrode and a filling material, the filling material is adopted to replace part of the suspension electrode, or different filling materials are arranged near the suspension electrode, and the line width of the suspension electrode is selectively set; the method is used for changing the frequency or displacement distribution of a parasitic mode with vibration distribution in an area outside a longitudinal electric field, so that the aim of removing the parasitic mode or completely inhibiting the parasitic mode is fulfilled. The scheme is an optimization scheme on the basis of not changing the structure of the piezoelectric film, is more beneficial to structure stability and can be used for manufacturing the high-frequency large-bandwidth acoustic wave filter with high performance on a large scale.

The invention relates to the technical field of semiconductors, in particular to an acoustic resonator, an acoustic filter and an acoustic filter module. The acoustic resonator at least comprises a piezoelectric film and an interdigital electrode; a preset crystal axis in the piezoelectric film serves as a first reference axis, the normal direction of the interdigital electrode pair serves as a second reference axis, and a preset included angle is formed between the first reference axis and the second reference axis; the average tangential direction of the first gap track and the average tangential direction of the second gap track in the interdigital electrode meet a preset condition. The electromechanical coupling coefficient of the acoustic resonator is adjusted by changing the acoustic wave propagation direction in the acoustic wave surface. Moreover, by designing a first gap track tangential angle and a second gap track tangential angle, the electromechanical coupling coefficient of the acoustic resonator is changed, and energy leakage caused by an overlarge energy flow incident angle is avoided. Therefore, acoustic wave resonators with different electromechanical coupling coefficients can be realized on the same piezoelectric film, and then acoustic wave filters with different relative bandwidths are realized.

A sound pickup device includes a processor with hardware. The processor calculates a first relational expression between acoustic filter factors of acoustic filters applied to microphone acquisition signals acquired by two or more microphones, based on a multiplication factor at a sensitization control point with high sound pressure sensitivity by the two or more microphones and a transfer function between each of the two or more microphones and the sensitization control point. The processor calculates a second relational expression between the acoustic filter factors, based on information of a frequency of a sound source and an interval between the two or more microphones. The processor calculates each of the acoustic filter factors, based on the first relational expression and the second relational expression.

The application relates to the fields of material preparation technology and radio frequency devices, in particular to a thin film substrate structure and an acoustic filter. The thin film substrate structure comprises a supporting substrate, an interface layer, an insulating layer and a functional layer; the supporting substrate has opposite first and second surfaces, and the interface layer is located on the second surface; the insulating layer is located on the side surface of the interface layer away from the supporting substrate; the functional layer is located on the side surface of the insulating layer away from the supporting substrate; and the interface layer has at least one of a deep energy level defect and a preset band gap width. The application plays a pinning effect on the Fermi level of the device by the interface layer having at least one of a deep energy level defect and a preset band gap width. The surface local conductance effect of the supporting substrate when working at a high frequency is effectively inhibited, the generation of high-order harmonics is inhibited, and the linearity of the device is optimized.

The application relates to the field of wireless communication technology and provides an acoustic filter and a preparation method thereof.The preparation method comprises the following steps: S1, providing a substrate, forming an acoustic layer on the surface of the substrate, and forming an effective acoustic structure by using the acoustic layer; wherein the effective acoustic structure comprises an acoustic resonance structure, an input end part, an output end part and a ring-shaped grounding end; S2, forming a separation layer on the side of the effective acoustic structure away from the substrate, so that the separation layer completely covers the acoustic structure, and etching an electrical connection window through the separation layer; S3, forming a connecting layer on the side of the separation layer away from the effective acoustic structure, so that the connecting layer completely covers the separation layer, and the connecting layer is connected with the ring-shaped grounding end of the acoustic layer after penetrating through the electrical connection window, thereby obtaining the acoustic filter; wherein the thickness of the connecting layer is the same as the thickness of the acoustic layer.The acoustic filter has low manufacturing cost and is miniaturized as a whole.

The invention discloses a lumped element and acoustic resonator mixed filtering balun and radio frequency front end system, which comprises a first module, a second module, a third module, a fourth module, a fifth module, a sixth module and a seventh module, and is characterized in that the first module, the third module and the fourth module are acoustic-electric mixed modules and comprise lumped elements and acoustic resonators; the first module, the fifth module, the sixth module and the seventh module are used for forming a plurality of transmission zero points outside a passband of the filtering balun so as to enhance the selectivity and out-of-band rejection of the edge of the passband, and the second module, the fifth module, the sixth module and the seventh module are electric modules, are formed by lumped elements and are used for realizing the passband of the required filtering balun. Reflection loss caused by impedance mismatching when discrete devices are cascaded can be avoided, insertion loss of a system is remarkably reduced, the size and cost of the system are reduced, the broadband advantage of an electrical filter and the high selectivity advantage of an acoustic filter are integrated, and meanwhile the high-performance filtering balun which is miniaturized, large in bandwidth and high in selectivity is achieved.

The invention discloses an acoustic filter screen capable of adjusting power distribution. The acoustic filter screen comprises a filter screen body used for covering a sound outlet of a loudspeaker box and a through hole formed in the filter screen body. The filter screen body comprises a sector, a short arc edge and a long arc edge which are positioned at two ends of the sector, and a diameter edge for connecting the short arc edge and the long arc edge; the sector is bent downwards from the center of the sector to the two diameter sides to form a conical surface shape; the multiple through holes penetrate through the sector, and the hole diameters of the through holes are gradually increased in the direction from the short arc edge to the long arc edge. The invention also provides a sound box. According to the acoustic filter screen capable of adjusting power distribution, distribution and diffusion of acoustic energy are adjusted through the through holes, the diameters of the through holes are gradually increased from inside to outside, namely from the short arc edge to the long arc edge, and the perforation rate of the acoustic filter screen is gradually increased. By adjusting the acoustic filter screen, the sound energy is spread more uniformly, the unevenness of the sound pressure level of the listening surface is reduced, and the sound quality of the sound equipment is improved.

An acoustic transformer in a transmitter chain is disclosed. In one aspect, a differential power amplifier may produce a differential signal that is provided to a first transformer. A differential output of this first transformer is provided to an acoustic transformer that provides a single ended output signal for use by an acoustic filter. By making the second transformer an acoustic transformer, the second transformer may be integrated into the same circuitry that forms the acoustic filter, thereby simplifying the die. Further, the acoustic transformer may be tuned if ferroelectric resonators are used, which provides strong out-of-band signal cancelation.

An acoustic filter, a production method therefor, and an electronic device are provided. The acoustic filter includes a piezoelectric substrate and an interdigital transducer located on a side of the piezoelectric substrate. The interdigital transducer includes a first bus bar and a second bus bar. An edge region, a gap region, a central region, and a slant region that are arranged in a first direction are included between the first bus bar and the second bus bar. Parts that are of a first electrode finger and that are located in the edge region, the gap region, and the central region are parallel to the first direction, and a part of the first electrode finger and that is located in the slant region is slanted relative to both the first direction and a second direction.

Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern comprising an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate.