262 results about "Cavity resonance" patented technology

A measurement system and method of conducting cavity resonance and waveguide measurements is disclosed. The cavity or waveguide may be used to monitor the amount, composition, or distribution of a material or sample contained in the cavity or waveguide or passing through the cavity or waveguide. Improved means for operating the measurement system to reduce measurement variability, improve measurement accuracy, and decrease measurement response times are described. The invention's broad applications range from measurements of filters, catalysts, pipe, and ducts where the material collected in or passing through the cavity or waveguide exhibits dielectric properties different from the material which it displaces.

The invention relates to a fluctuating pressure and pneumatic noise suppression device for three-dimensional cavity resonates, belonging to flow control technical field, comprising an aligned array groove, an actuating reed, a piezoelectric ceramic piece, an installing seat, a special high voltage power supply for piezoelectric ceramic, a dynamic pressure transducer and a computer with an A / D acquisition card. The dynamic pressure transducer is arranged under the cavity, and is connected with the computer with A / D acquisition card by the through hole under the cavity. The actuating reed is arranged in the aligned array groove. The piezoelectric ceramic piece is pasted on the bottom of the reed to be the excitation element. The piezoelectric ceramic piece is connected with the special high voltage power supply for piezoelectric ceramic. The piezoelectric ceramic piece produces extensional deformation under the control signal excitation, and drives the actuating reed to vibrate, the oscillation frequency of the shear layer is changed, the cavity resonates is broken down, and the cavity pneumatic noise is suppressed. The fluctuating pressure and pneumatic noise suppression device for three-dimensional cavity resonates has the advantages of wide adjustable range, realizing the accurate control of the phased array for the three-dimensional space of the cavity by the real time feedback of the fluctuating pressure of cavity.

The present invention provides a new approach for subwavelength cavity solutions. Employment of a reflecting metasurface based on plasmonic nanostructure elements changes the cavity resonance condition that currently causes restrictions on minimum length. The short length of wave propagation between the cavity walls is compensated by strong localization of electromechanical energy near the metasurface walls, which experience considerable phase shifts over a very small distance. Subwavelength 2D and 3D cavities find implementation as laser sources, optical parametric oscillators, interferometers, laser phase and frequency stabilizers, laser spatial and temporal filters, adaptive beam, and pulse shaping devices.

Disclosed is a low noise pneumatic tire having a configuration where, while installation work of a strip-shaped sound absorbent is simple, it is possible to simultaneously reduce cavity resonance and high-frequency noise, and thereby to effectively reduce noise when a vehicle is traveling. In the low noise pneumatic tire of the present invention, the strip-shaped sound absorbent is attached to an annular elastic fixing band, and then is installed onto an inner surface of a tread of the tire taking advantage of the elastic force of the annular elastic fixing band. The strip-shaped sound absorbent is formed of at least two kinds of porous materials whose sound absorption characteristics with respect to frequencies are different from one another.

A method for producing a pneumatic tire in which a noise damper in the form of at least one continuous ribbon for reducing cavity resonance in a tire cavity is provided on the internal surface of a tire on the inside in the radial direction of the tire corresponding to the tire tread, including, providing a vulcanized and shaped tire; mixing a composition for forming the noise damper with a foaming agent to produce a liquid composition; rotating the tire in an upright state by means of a tire holding and rotation device, and introducing the liquid composition onto the tire internal surface by a device for introducing the liquid composition; varying the relative positional relationship of the pneumatic tire and the introduction implement in the axial direction of the tire while introducing the liquid composition is introduced onto the tire internal surface, and forming the liquid composition into a gel; and foaming and drying the gelled liquid composition.

The invention relates to a novel bending micro-strip ridge substrate integrated gap waveguide structure. In a double-layer dielectric plate bending micro-strip ridge substrate integrated gap waveguide formed by bonding a via hole layer dielectric plate and a gap layer dielectric plate, a metal layer is printed on the upper surface of the via hole layer dielectric plate, an arc bending first micro-strip line is arranged on the lower surface of the via hole layer dielectric plate, the first micro-strip line adopts an arc bending design, a first via hole, a second via hole, a micro via hole and a first micro-strip line form a bending micro-strip ridge structure, a plurality of periodical via holes are uniformly formed in two sides of the bending micro-strip ridge structure respectively, a metal circular patch is arranged under the periodical via holes, an arc bending second micro-strip line is arranged on the upper surface of the gap layer dielectric plate, a first gradual change line and a second gradual change line are arranged at two ends of the second micro-strip line respectively, and a metal layer is printed on the lower surface of the gap layer dielectric plate. According to the structure, the problems of bending discontinuity and cavity resonance are solved, and meanwhile, the structure has the advantages of simple structure, easy integration, simple processing, small size, wide broadband, low loss and structure stability and the like.

Disclosed are a pneumatic tire and a tire cavity resonance suppression device in which noise by cavity resonance is effectively reduced without any changes in tire and rim production facilities. The pneumatic tire is constituted by that an object, which is changed in sectional area in accordance with a position in a tire circumferential direction, is fixed to a tread inner surface by a ring-shaped jig made of an elastic body. The tire cavity resonance suppression device includes an object changed in sectional area in accordance with a position in a tire circumferential direction and a ring-shaped jig made of an elastic body for locking the object to a tread inner surface of the tire.