44results about How to "Applicable frequency range is wide" patented technology

The invention provides a magnetorheological elastomer intelligent vibration absorber used for ships, which comprises an outer shell, a magnetorheological elastomer, a magnetic coil group and an internal iron core. The outer shell, the magnetorheological elastomer, the magnetic coil group and the internal iron core are together distributed on the same concentric circle. The inner surface of the outer shell is tightly connected with the outer surface of the magnetorheological elastomer by a bond. The inner surface of the magnetorheological elastomer is stuck into a whole body with the inside iron core by the bond. The coils are divided into four groups and are respectively twisted on the internal iron core. The invention is prepared by using the characteristic that the magnetic shearing rigidity of the magnetorheological elastomer is changed with the changing of the current, and has the advantages of simple structure, good vibration absorption effect, broad applicable frequency bands(using frequency bands of several HZ to scores of HZ), strong environment adaptive capacity(resisting oil stain and dampness), good stability (the control effect is not reduced after being used for a long period), etc.

This is the producing method of a kind of polymer / inorganic mineral compound foam sound absorption material. Mix round equably following components as weight proportions: resin 20 - 50%, rubber 0 - 50%, inorganic mineral 20 - 60%, vesicant 3 - 5%, fire retarder 0.5 - 3%, and stabilizing agent 1- 4%; mixed smelt the said mixture on mixing roll for 5 - 20 minutes at 90 - 140 Deg. C to produce needed flan; chemistry froth produced flan in drying oven for 5 - 15 minutes at 150 - 220 Deg. C. According to the theory that different polymers and inorganic substances have different responses to sound frequency, the invention adopts the multi-component polymer and inorganic substance mixing method, and has both advantages of organic and inorganic materials, so it improves sound absorption performance in the middle and low frequency range.

The invention discloses a substrate integrated waveguide filter with the characteristic of controllable hybrid electromagnetic coupling. The substrate integrated waveguide filter comprises a substrate integrated waveguide resonance cavity. The substrate integrated waveguide resonance cavity consists of a dielectric substrate, two metal layers arranged at the front side and the back side of the dielectric substrate, and peripheral metallic through holes that are formed along the edges of the dielectric substrate and penetrate the two metal layers. An input port and an output port are arranged at the two ends of the substrate integrated waveguide. A plurality of internal metallic through hole groups are formed in the area encircled by the peripheral metallic through holes and include internal metallic through holes that are arranged at two columns in a collinear mode; a sensitive window is formed between the two columns of the internal metallic through holes. A non-resonant node structure arranged above the sensitive window is arranged on the upper metal layer. According to the invention, the electric coupling strength is controlled by adjusting the non-resonant node structure and the magnetic coupling strength is controlled by adjusting the width of the sensitive window, so that whether the transmission zero point is arranged on an upper stop band or a lower stop band can be controlled.

The invention discloses a self temperature compensation round waveguide TE011 mode resonant cavity which can obviously decrease the influence of the temperature on the resonant frequency of the resonant cavity. In the resonant cavity, a metal cavity (1) is a hollow cylinder; a short-circuit board (2) is arranged in the metal cavity (1); the short-circuit board (2) is connected with an upper bottom cavity wall (5) of the metal cavity (1) by a support (3); the coefficient of thermal expansion of the support (3) is more than the coefficient of thermal expansion of the metal cavity (1); one end of the support (3) is fixed on the upper bottom cavity wall (5) of the metal cavity (1) while the other end is fixed on the short-circuit board (2); the short-circuit board (2) is of a round disc shapeand is slightly smaller than the upper bottom cavity wall (5); the short-circuit board (2), an upper bottom cavity wall (6) of the metal cavity (1) and a side wall (7) of the metal cavity (1) form anelectromagnetic wave resonance space (8); and an input output coupling device (4) is arranged on the side wall (7) or the upper bottom cavity wall (6) of the metal cavity (1) of the electromagnetic wave resonance space (8).

The invention discloses a self-temperature compensating rectangular waveguide resonant cavity, which relates to the waveguide resonant cavity and can remarkably decrease the influence of temperature on the resonance frequency of the resonant cavity. A short circuit board (2) is positioned in a metal cavity (1). The thermal expansion coefficient of a support body (3) is greater than that of the metal cavity (1). The short circuit board (2) is connected with the top cavity wall (5) of the metal cavity (1) through the support body (3) and is of a shape similar to that of the top cavity wall (5) and in a size slightly smaller than that of the top cavity wall (5). The short circuit board (2), and another top cavity wall (8), the narrow cavity wall (6) and the wide cavity wall (7) of the metal cavity (1) form a resonant space (9) of electromagnetic waves. An input and output coupling device (4) is positioned on the top cavity wall (8) or the narrow cavity wall (6) or the wide cavity wall (7) of the metal cavity (1) in the resonant space (9).

The invention discloses an online monitoring and diagnosing method for common faults of marine medium-speed diesel engine combustion chamber parts. Acoustic emission sensors are arranged on an enginecylinder cover and the outer side of an engine body correspondingly, feature parameters representing the different faults are extracted from fault mechanisms, and the common faults of the marine medium-speed diesel engine combustion chamber parts are monitored and diagnosed on line. The different faults of the diesel engine combustion chamber parts can be monitored and diagnosed only through the two acoustic emission sensors, the types of sensors are less, the number of the sensors is small, monitoring is comprehensive and efficient, and the method is easy to implement and has wide applicationprospects.

The organic polymer as electromagnetic shielding material and its preparation process belongs to the field of material science and technology. The organic polymer as electromagnetic shielding material has organic polymer of polymerization degree n of 20-400 in the shown structure as the main component. It is prepared with the monomer with aniline and ferrocene as main material, and through slowly dropping oxidant solution into the monomer solution to polymerize and adding proper amount of dopant. The polymer has in its molecular structure polyaniline as the conducting mother substance and ferrocene as the magnetic radical, so that it has both electric conductivity and magnetism. It has high comprehensive shielding effect, low density, wide applicable frequency range, low temperature coefficient, low magnetic loss and other excellent characteristics, and may find wide application in electromagnetic shielding, wave absorption, etc.

The invention discloses a Gysel-type power divider based on a substrate integrated waveguide, and the power divider comprises a first port, a second port, a third port, a fourth port, and a fifth port. The first port is disposed on a central line of the power divider, and the power divider is symmetric relative to the central line. The first port is a common port, and the second and third ports are branch ports. The fourth and fifth ports are load ports. The power divider employs a substrate integrated waveguide structure, and comprises an upper metal surface, a central dielectric plate, and a lower metal surface. Two rows of second metal post line columns are disposed between the upper metal surface and the lower metal surface. Each row of second metal post line columns comprises a plurality of metal columns, and each metal column contacts with the upper metal surface and the lower metal surface. The power divider meets the actual demands of high power and high isolation, is small in size, is light in weight, and is suitable for the power combination and distribution of various types of SIW systems.

The invention relates to a miniature piezoelectric and capacitance composite vibration energy harvester, belonging to the technical field of MEMS (micro electro mechanical system) and micro energy. A piezoelectric energy harvesting unit is connected with the upper part of a support body, the lower part of the support body is bonded on a base body, and the interior of the support body is provided with a capacitance energy harvesting unit in which electrolyte is provided. The harvester has the advantages that a same mechanism is adopted to realize the energy harvesting of two different mechanisms, so as to achieve the effect of superimposing and magnifying the output energy, the energy conversion efficiency of a device is improved further by the structures of piezoelectric and capacitance energy harvesting units, broadband vibration energy harvesting can be realized efficiently, and the harvester is especially suitable for the vibration energy harvesting in a low-frequency small-amplitude environment.