233results about How to "Improve filter characteristics" patented technology

Compositions, methods and kits for purifying and clarifying and / or nutrifying contaminated drinking water and which comprise a primary coagulant material, a microbiocidal disinfectant and an oxidant system. Highly preferred compositions also contain one or more of a bridging flocculent material, the levels and ratios of coagulant to flocculent preferably falling within certain ranges, a cationic coagulant aid, especially chitosan, a water-soluble alkali, a water-insoluble silicate, and a food additive or nutrient source. The purified water remains free of discoloration for extended periods of storage.

A thin film bulk acoustic resonator includes a piezoelectric film, and a pair of electrodes between which the piezoelectric film is interposed. The piezoelectric film includes an outer region extending outwards from at least a portion of the periphery of a resonator portion composed of the pair of electrodes and the piezoelectric film. The outer region includes, in at least a portion thereof, an acoustic damping region for damping acoustic waves.

A high-frequency module includes a propagation path that has a simple structure and improves filter characteristics by causing an inductor and a matching network to electromagnetic field couple with each other such that attenuation characteristics outside of a frequency band of a transmission signal are improved without increasing the size of the high-frequency module. In addition, unintended electromagnetic field coupling between a first filter and the inductor is significantly reduced or prevented by a shield electrode. Therefore, unintended propagation of a high-frequency signal is significantly reduced or prevented. Therefore, the attenuation characteristics outside of the frequency band of transmission signal input to the transmission terminal are improved more effectively.

A duplexer that includes: a transmission filter and a reception filter that are connected to a common terminal; and a reactance circuit that is connected to at least one of the transmission filter and the reception filter. The reactance circuit includes an insulating substrate, lumped-constant inductors, and at least one capacitor. The lumped-constant inductors and the capacitor are formed directly on the surface of the insulating substrate.

An elastic wave device includes a medium layer, a piezoelectric body, and an IDT electrode that are disposed on a supporting substrate. The medium layer is made of a medium containing a low-velocity medium in which a propagation velocity of a same bulk wave as that which is a main vibration component of an elastic wave propagating in the piezoelectric body and being used is lower than a propagation velocity of the elastic wave, and a high-velocity medium in which the propagation velocity of the same bulk wave as that which is a main vibration component of the elastic wave is higher than the propagation velocity of the elastic wave.

A duplexer that includes: a transmission filter and a reception filter that are connected to a common terminal; and a reactance circuit that is connected to at least one of the transmission filter and the reception filter. The reactance circuit includes an insulating substrate, lumped-constant inductors, and at least one capacitor. The lumped-constant inductors and the capacitor are formed directly on the surface of the insulating substrate.

The invention discloses a full-duplex active phased filter antenna array surface, and aims at providing an antenna array surface with high-isolation array transmitting and receiving and good filter characteristic. A transmitting antenna array surface of a transmitting array antenna and a receiving antenna array surface of a receiving array antenna consist of a plurality of arrayed radiation units;a multi-layer printed board integrally integrating a radiation circuit, a feed switching circuit and a filter circuit achieves connection between different circuits by vertical interconnection structures of metallized via holes; a metal upper cavity body of a transmitting-receiving component serves as a metal ground; a metal upper cavity body base of a metal floor is consubstantially connected byradio-frequency fuzz button connectors; and then a radiation unit and transmitting-receiving component integrated box-type submatrix module filter antenna unit is formed. With the adoption of the full-duplex active phased filter antenna array surface, high-isolation array transmitting and receiving can be achieved; insertion losses of array transmitting and receiving can be reduced; and high-precision amplitude and phase control can be achieved.

A method of producing a ceramic filter element suitable for use in an exhaust filter for an internal combustion engine, during which a combustible, non-ceramic support web is impregnated with a ceramic slip and formed into a desired geometric shape in either order, and then the impregnated and formed web is fired until the support web is burned out and a rigid ceramic filter body is formed.

A duplexer includes two surface acoustic wave filters that are formed on one substrate, at least one of the two surface acoustic wave filters being a ladder filter. In this duplexer, the positional difference between the centers in the surface acoustic wave propagating direction of each two neighboring comb-like electrodes among comb-like electrodes that form series-arm resonators in the ladder filter is equal to or smaller than a fourth of the length in the propagating direction of the comb-like electrode having the larger number of pairs of electrode fingers of each two neighboring comb-like electrodes.

An elastic wave device includes IDT electrodes stacked on a piezoelectric thin film. The IDT electrode includes a plurality of first electrode fingers and a plurality of second electrode fingers. A line connecting the distal ends of the first electrode fingers or the distal ends of the second electrode fingers extends obliquely with respect to a propagation direction of an elastic wave at an oblique angle ν. The oblique angle ν is about 0.4° or more and about 10° or less.

A planar filter has first and second U-shaped open transmission line resonators (103, 105) and a crank-shaped open transmission line resonator (104), so that it is possible to decrease an area to be virtually occupied by the filter on a dielectric substrate (110) and enhance the attenuation characteristic.

The invention discloses a frequency-selection-surface invisible radome with a dielectric medium truss structure and belongs to the technical field of modern weapons. The radome takes a dielectric medium truss as a skeleton network to support an FSS (frequency Selective Surface) flexible screen so as to realize a stable filtering characteristic and further improve the invisibility and reliability of the FSS radome. The radome comprises a radome base, the dielectric medium truss, a flexible base and the FSS screen; the radome is of a closed structure and sequentially comprises the radome base, the dielectric medium truss, the flexible base and the FSS screen from the outermost layer to the innermost layer; and the radome base, the dielectric medium truss, the flexible base and the FSS screen are connected with adjacent parts. According to the invention, the ideal filtering characteristic of the FSS radome which utilizes air as a matching medium can be realized, the stable passband of electromagnetic waves which are incident with large angels and in different polarization ways can be maintained, and detection radar waves emitted by an enemy can be reflected to other directions so as to reduce echo signals, thereby realizing the aim of invisibility of a radar.

The invention discloses a multi-cascade fiber bragg grating filter. The filter mainly comprises an input optical fiber, an output optical fiber and a multi-cascade optical fiber bragg grating, wherein the first end of the input optical is connected to a signal light source, and the second end of the input optical fiber is connected with the head end of the multi-cascade optical fiber bragg grating; the tail end of the multi-cascade optical fiber bragg grating is connected with the first end of the output optical fiber, and the second end of the output optical fiber outputs a signal light source; the multi-cascade optical fiber bragg grating is mainly composed of a plurality of optical fiber braff grating groups which have different central periods and are connected in series end to end; and each optical fiber bragg grating group is mainly composed of a plurality of unit gratings which have the same central period and are connected in series end to end. The filter has the advantages that: the filter reflects wavelengths under different Bragg conditions to greatly extend the filter range; meanwhile, filter channels are distributed at equal intervals; and the filter has the characteristics of multiple channels (the number of the channels is more than 40), high density (the channel interval is less than 0.5nm), high reflection (the reflection is approximate to 100 percent), good waveband selectivity and the like, and realizes ultra-wideband tunable comb filtering.

A differential rate rotary thickener; a power detector which is disposed in a sludge receiver tank for thickened sludge thickened in the differential rate rotary thickener; a discriminator which receives an electric signal for a thickened sludge concentration (X) detected by the power detector and which calculates and discriminate the data; a first controller which receives an instruction signal being a discriminated result in the discriminator and which operates an outer cylinder driving machine and a screw driving machine; a ratio setter which receives a discriminated signal of the discriminator and which increases or decreases a chemical feed rate (α) of flocculant stepwise; and a second controller which receives an instruction signal from the ratio setter and which operates a flocculant-feeding pump are provided. Thickening of sludge is performed by controlling the chemical feed rate (α), a rotational speed (S) of a screw, and a rotational speed (C) of an outer cylinder screen.

The invention discloses a broadband slot antenna with a filter character. The broadband slot antenna comprises a dielectric medium substrate, a micro-strip structure formed on a metal foil on the upper surface of the dielectric medium substrate, a slot structure which is formed on a metal foil on the lower surface of the dielectric medium substrate and is provided with a groove in the ground, and a metal via hole which is formed in the dielectric medium substrate in an up-and-down penetrating manner, wherein the metal via hole passes through the micro-strip structure and the group at the same time, and the micro-strip structure comprises two structures such as a micro-strip feed structure and a micro-strip resonator structure. The micro-strip feed structure is used for coupling energy to the micro-strip resonator structure, so that a plurality of resonant mode stimulation slot radiation structures are generated by the micro-strip resonator structure, and the purposes of expanding bandwidth and having the filter characteristic are achieved at the same time. The broadband slot antenna with the filter character disclosed by the invention is simple in structure, light in weight and easy for processing and manufacturing, and is suitable for various wireless terminals.

The invention discloses a signal conditioning circuit for an acceleration sensor with a high g value. The signal conditioning circuit is composed of an isolation amplification circuit, an alternating-current coupled circuit, a first voltage following circuit, a voltage bias circuit, a low-pass filter circuit and a second voltage following circuit sequentially connected in series; the isolation amplification circuit is used for performing signal isolation amplification and power supply isolation of a sensing signal Signal_in output by the acceleration sensor with the high g value and then outputting an isolation amplified signal Signal_out1; and the low-pass filter circuit is a unit gain two-order voltage-controlled voltage source low-pass filter circuit constructed by utilizing an integrated operational amplifier. According to the invention, the signal waveform can be improved; frequency confusion while discretizing is prevented; adverse effects of noise are overcome in the event that the signal and a noise spectrum are not overlapped; the signal to noise ratio is increased; furthermore, aiming at different attack targets, sensor signals can be effectively modified; preceding-stage analogue signals easy to identify and process are provided for a burst control algorithm precisely damaged by a hard target penetration warhead; and the signal conditioning circuit can stably work in a 100000g impact environment.

The invention discloses an electromagnetic hybrid coupling-based micro-strip duplexer, which comprises a double-faced copper-plated micro-strip board, wherein two filters with controllable passband frequency and bandwidth, a first port feeder, a second port feeder, a T-joint, a first port, a second port and a third port are formed on one surface of the double-faced copper-plated micro-strip board, and a copper-plated grounding plate is arranged on the other surface of the double-faced copper-plated micro-strip board; the two filters are respectively formed by three quarter-wave micro-strip resonators coupled with one another, a connection part at one end of the three resonators is provided with a grounding hole, and electric coupling is generated between every adjacent resonators in each filter. According to the duplexer, electric coupling is introduced on the basis of the original magnetic coupling, so that the bandwidth of the duplexer can be changed freely by adjusting the strength of the magnetic coupling and the electric coupling, and the improved filters can generate a plurality of transmission zero points near the upper and lower cut-off frequencies, so that mutual influence between the two filters can be reduced through adjusting the positions of the zero points.

In an acoustic wave filter, first and second filter elements are connected between an unbalanced terminal and first and second balanced terminals on an acoustic wave substrate. The filter elements are longitudinally-coupled surface wave filters including at least three IDTs. One end of the IDTs is mutually connected and is connected to the unbalanced terminal. The other ends of the IDTs are connected by a second connecting line so as to define an unbalanced-side grounded portion. Grounded ends of the IDTs are connected to each other by a first connecting line so as to define a common midpoint grounded portion. The common midpoint grounded portion and the unbalanced-side grounded portion are electrically separated from each other.

A film bulk acoustic resonator includes a lower electrode that is formed on a void of a substrate or is formed so that a void is formed between the lower electrode and the substrate, a piezoelectric film that is formed on the lower electrode, an upper electrode that is formed on the piezoelectric film so as to have a resonance region facing the lower electrode through the piezoelectric film, a support region that is provided around the resonance region, has a width of 0.35 times to 0.65 times a wavelength of a wave propagating in a lateral direction, and transmits the wave passes, and an adjacent region that is provided around the support region and blocks the wave.

A duplexer includes two surface acoustic wave filter having different band center frequencies, and a phase matching circuit that matches the phases of the two surface acoustic wave filters to each other. In this duplexer, one of the two surface acoustic wave filters is a ladder type surface acoustic wave filter, while the other one of the two surface acoustic wave filters includes two or more dual-mode type surface acoustic wave filters that are connected in parallel.

The invention discloses a kind of dynamic optical wavelength router which is based on 1 * N of annulet. Input waveguide in a sandwich layer, N output waveguide and N annulet, N annulet is adjacent with a respective output waveguide. Top Cladding is corresponding to N annular electrode of N annulet, through the electro-optic effect, changes the refractive index of annulet, and controls resonator conditions of annulet, realizes coupling in different wavelengths optical signal between input waveguide and annulet, and between annulet and the output waveguide. N different wavelength optical signal inputs from the input waveguide, N output waveguide chooses a corresponding wavelength optical signal output respectively, wavelength of each output waveguide can be dynamic configuration. Chooses structure of annulet as the basic unit, the structure is simple and easy to achieve the miniaturization of devices and integration of function; the loss of annulet is low, the ratio of extinction is big, the factor of quality is high, it has excellent characteristics of filtering. It is easy to control resonator conditions of annulet by using electro-optic effect, realizes dynamic configuration of the output wavelength.

A duplexer includes a multilayer package, SAW filters that have different band center frequencies and are provided in the multilayer package, and a phase matching line that matches phases of the SAW filters and are provided in the multilayer package. A ground pattern with respect to the phase matching line is provided on a mount surface of the multilayer package.

The invention relates to a submillimeter wave FSS (frequency selective surface) with a loading fractal structure, wherein the submillimeter wave FSS has double frequency band-pass characters, the first central operating frequency is 424GHz, and the 3dB operating frequency is 387-452GHz; the second central operating frequency is 556GHz, and the 3dB operating frequency is 538-593GHz; the device is realized by an array consisting of multiple periodic resonance units, the center of each periodic resonance unit is provided with a Y-shaped three-arm seam, and one three-arm fractal seam pattern is loaded around each Y-shaped seam at every 120 degrees; and the FSS comprises a first silicon material layer, a first metal layer, a second silicon material layer, a second metal layer and a third silicon material layer, the structures of the five layers are cascaded, and the adjacent layers are tightly adhered.

A radio frequency module includes a transmission terminal, a transmission filter connected to the transmission terminal, a common terminal, a reception filter which is connected to the common terminal, a reception terminal, a branch point to which the common terminal, the transmission filter, and the reception filter are connected, a transmission path connecting the transmission terminal and the branch point, a reception path connecting the reception terminal and the branch point, a common path connecting the common terminal and the branch point, a matching circuit connected to the common path, and an inductor circuit that includes a first inductor that defines a propagation path through electromagnetic coupling to at least one of the transmission path, the common path, the matching circuit, and the reception path, and a second inductor that is positioned so as not to be electromagnetically coupled to the transmission path, the common path, the matching circuit, or the reception path.

The invention belongs to the technical field of automatic control of a power system, in particular to a scattered power generation reactive compensation device and method with the harmonic suppression function. The scattered power generation reactive compensation device comprises an A-T mixing reactive compensation unit, a central control unit and a power supply module. The A-T mixing reactive compensation unit comprises a thyristor control reactor set (TCR), an active power filter (APF) and a passive filter set, wherein the thyristor control reactor set is connected with a compensation access point between the passive filter set and a power grid main line, and the active power filter and the passive filter set are in serial connection to form a mixing active filter. The central control unit can output pulse width modulation signals and triggering pulse signals which can respectively trigger an APF thyristor and a thyristor in the thyristor control reactor set. The scattered power generation reactive compensation device and method with the harmonic suppression function can effectively restrain resonance between the passive filter and the power grid, enables harmonic compensation accuracy to be higher and system response to be quick, improves reactive compensation safety and is economical and practical.

An elastic wave filter device includes a longitudinally coupled resonator-type elastic wave filter formed on a piezoelectric substrate; and a ladder-type elastic wave filter connected to the resonator-type elastic wave filter. The resonator-type filter includes an input IDT and an output IDT. The ladder-type filter includes a series arm resonator and a parallel arm resonator. A first ground electrode connected to the parallel arm resonator is electrically separated from a second ground electrode connected to at least one of the input IDT and the output IDT.

An acoustic wave element includes an IDT electrode in contact with a piezoelectric material and including a plurality of electrode fingers, which include first and second electrode fingers that adjoin each other in an acoustic wave propagation direction and that connect to different potentials and a first dummy electrode finger facing the first electrode finger via a gap located on an outer side in an electrode finger length direction of the first electrode finger. At an area near the gap, first protrusions are provided in at least one of the first electrode finger and the first dummy electrode finger, the first protrusion protruding in the acoustic wave propagation direction from at least one of side edges of the at least one of the first electrode finger and the first dummy electrode finger. The acoustic wave element has greatly improved resonance characteristics of a resonance frequency and prevents short-circuit failure between electrode fingers and degradation in insulation properties.

A cylindrical frequency selective surface structure belongs to the technical field of wireless communication and solves the problems of poor filtering characteristic and stability generally existing in a curved frequency selective surface. The cylindrical frequency selective surface structure disclosed by the invention comprises a metal layer and a dielectric layer with a thickness of 1 millimeter, the dielectric constant of the dielectric layer is 2.2, the magnetic conductivity of the dielectric layer is 1, through holes are fully etched on the surface of the metal plate in a rectangular lattice shape and are Y-shaped, the distance of each two adjacent Y-shaped through holes is 40 millimeters, the metal plate (1) is bent according to a cylindrical surface with a curvature radius of 160 millimeters, and the dielectric layer is in contact with the inner side of the metal layer. The cylindrical frequency selective surface structure is suitably used as a conformal cylindrical antenna cover.

The present invention provides a filter exhibiting excellent filter characteristics and having less number of stages. A dielectric substrate (1) has one surface connected to a top conductor (2) and an opposite surface connected to a bottom conductor (3). A pair of rows of via-holes connecting together the top conductor (2) and the bottom conductor (3) are formed along the signal transfer direction. A slit (6) is formed in a portion of the top conductor (2) overlying the central resonator among a plurality of resonators. The slit (6) extends in a direction perpendicular to the signal transfer direction. Slits (7, 8) are formed in each of portions of the top conductor (2) overlying resonators disposed at both ends. A coplanar waveguide (9) mounted on the top conductor (2) is connected to the slit (7).