67 results about "Quarter wavelength resonator" patented technology

A band-pass filter comprises a first resonator, a second resonator and a third resonator. The second resonator is magnetically coupled to the first resonator. The third resonator is magnetically coupled to the second resonator and is electrically coupled to the first resonator. In addition, the first resonator is a quarter wavelength resonator, the second resonator is a half wavelength resonator, and the third resonator is a quarter wavelength resonator.

The invention discloses a wide-stopband LTCC (low temperature co-fired ceramic) band-pass filter based on a magnetoelectric coupling counteraction technology. The wide-stopband LTCC band-pass filter based on the magnetoelectric coupling counteraction technology comprises two quarter-wave resonators, a metal floor and a pair of feed structures, wherein the resonators and feed patches are distributed on four conductor layers; the first layer is a feed layer with large feed patches and CPW (coplanar waveguide) feed ports; the two quarter-wave resonators are distributed at the second layer and the fourth layer, and the third layer is a grounding layer; the feed patches transmit energy to the resonators by means of broadside coupling; the resonators transmit energy to each other via side coupling, magnetic coupling and electric coupling exist between the two resonators simultaneously, the coupling in intervals close to a grounding end mainly is the magnetic coupling, and the coupling in intervals close to the open-circuit ends of the resonators mainly is the electric coupling; and the position of the transmission zero point of the filter can be conveniently adjusted by adjusting the intensities of the magnetic coupling and the electric coupling. The wide-stopband LTCC band-pass filter based on the magnetoelectric coupling counteraction technology disclosed by the invention is provided with a plurality of transmission zero points, as well as is excellent in selectivity and stopband suppression performance, and compact in structure.

This invention relates to semi-mode base slice integration waveguide filter applied in microwave circuit design, which comprises base, metal sticking pad, metal hole, and tank beam, wherein, metal sticking pad on medium base surface with rectangle in middle part and with two sides connected to input and output ends; locating one row of metal holes in one side in metal sticking part and other side set with tank seam; two tank beam one semi-mode base integration waveguide form one quarter of wave length resonance.

The construction is a coaxial cavity resonator (20, 30, 40, 50) comprising at least one conductive body (11, 31), which body is open at one end and shortened from a quarter-wave resonator. The conductive body includes a main rod (16), which is in one end attached to the cavity wall (15), and a main disc (17) attached to the free end of the main rod (16). The cavity (12) further comprises one or more conductive plates (21, 41, 51) located between the main disc (17) and the side walls (13), at the first side (17a) of, and out of galvanic contact with, the main disc (17). The shortening is carried out by creating air-insulated extra capacitance between the resonator cavity walls via the conductive plates and a mechanical structure at the open end of the conductive body.

The invention discloses a high-selectivity double band-pass filter with an independent adjustable passband, which comprises an upper micro-strip structure, a middle medium substrate and a lower ground metal plate. The filter is composed of four resonators; each resonator comprises a micro-strip line and a variable capacitance diode; the resonators are one fourth wavelength resonators, and are symmetrically arranged with respect to a central longitudinal shaft of the micro-strip structure. The first and second resonators take the micro-strip line, which is directly connected to the resonator and is parallelly coupled with the resonator, as a feed structure, while the third and fourth resonators take the micro-strip line, which is parallelly coupled with the resonator, as the feed structure. Besides, a pseudo cross finger structure is used to generate a transmission zero point, so that the filter is endowed with higher selectivity. The high-selectivity double band-pass filter with the independent adjustable passband has the characteristics of adjustable double passband central frequency and independent tuning.

The invention discloses a wide-stop-band LTCC band-pass filter based on the frequency selectivity coupling technology. The wide-stop-band LTCC band-pass filter comprises two quarter-wave resonators, a metal floor and a pair of feeder line structures. The resonators and the feeder lines are distributed on four conductor layers. The feeder lines transmit energy to the resonators in a broadside-coupled mode, and the resonators transmit energy to each other in a side-coupled mode. According to the wide-stop-band LTCC band-pass filter based on the frequency selectivity coupling technology, the frequency selectivity coupling technology is achieved by selecting a proper coupling interval, and therefore third harmonics can be effectively restrained; meanwhile, weak coupling, namely, source-load coupling, is introduced between the two feeder lines, two transmission zeros are generated near a pass band, and therefore good frequency selectivity is achieved; besides, a transmission zero is also generated on a stop band, and therefore the restraint level of the stop band is enhanced. The wide-stop-band LTCC band-pass filter based on the frequency selectivity coupling technology has the advantages of being capable of restraining the third harmonics, high in selectivity, multiple in transmission zero and compact in structure.

An air filtration cartridge has annular filter media having a hollow interior and extending axially between first and second distally opposite end caps. The first end cap is an outlet end cap having flow straightening structure integrally formed therewith and spanning the hollow interior. The second end cap is a closed end cap having an interior face having quarter wave resonators formed by blind holes therein.

A liner system for a steam outlet pipe of a turbine bypass system comprises a liner mounted in spaced coaxial relation to the inner pipe wall such that an annular cavity is defined between the liner and the steam outlet pipe. The cavity is open on an upstream end and closed on a downstream end such that a quarter-wavelength resonator is formed for attenuating noise associated with a flow of superheated steam passing through the steam pipe. The liner may include a plurality of perforations to further attenuate noise in the steam outlet pipe. The open upstream end and closed downstream end of the cavity increases pressure within the cavity to prevent cooling water from entering the perforations and contacting the inner pipe wall. A wire mesh disposed against the outer liner wall may block cooling water penetration through the perforations and may further attenuate noise associated with the flow of superheated steam.

The invention discloses an LTCC band-pass filter using a feed structure to restrain third harmonics. The LTCC band-pass filter using the feed structure to restrain third harmonics comprises two quarter-wavelength resonators, two feed patches and floors which are respectively distributed on nine conductor layers and connected through metal through holes, wherein the floors are located on the first, third, sixth and ninth conductor layers, the quarter-wavelength resonators are located on the second, fourth, fifth and seventh conductor layers, the feed patches are located on the eighth layer, the impedance characteristic of the feed patches can be changed by adjusting the distance between the eighth conductor layer and the ninth conductor layer, and therefore coupling of the feed patches and the resonators is changed. The coupling of the feed patches and the resonators can also be changed by changing the length of the feed patches, the feed patches are made to be mismatched with the resonators by adjusting the coupling of the two parts, and therefore the third harmonic part of the filter characteristics of the resonators is restrained, and the purpose of a wide stop band is achieved. The LTCC process adopted by the LTCC band-pass filter using the feed structure to restrain third harmonics comprises a multi-layer structure, the size of the filter is reduced, and the LTCC band-pass filter has novelty, creativeness and practicability.

The invention discloses a broadband three-mode Balun band-pass filter based on E multi-mode resonators, comprising an input feeder, a dual-port output feeder, a three-port output feeder, a first E multi-mode resonator, a second E multi-mode resonator, a dielectric substrate, and a metal ground plate. The first and second E multi-mode resonators are symmetrical stub-loaded multi-mode resonators. The input feeder, the dual-port output feeder, the three-port output feeder, the first E multi-mode resonator and the second E multi-mode resonator are disposed on the upper surface of the dielectric substrate, and the metal ground plate is disposed on the lower surface of the dielectric substrate. The first E multi-mode resonator includes two quarter-wave resonators and a symmetrical stub loading unit. The second E multi-mode resonator includes two quarter-wave resonators and a symmetrical stub loading unit. The broadband three-mode Balun band-pass filter has the advantages of simple structure, low loss, good selectivity and good port matching property, and is very applicable to a modern wireless communication system.

The invention provides an electric adjusting power divider with a filter function. The entire circuit structure of the electric adjusting power divider is symmetric, and the power dividing ratio is 1:1. Two pairs of quarter-wave resonators which are coupled with each other form two filter networks, and the characteristic of band-pass filtering is achieved. The matching of three ports of a circuit and the isolating of two output ports of the circuit are achieved by resistors. According to an on-load variable capacitance diode, the electrical length of the resonators and the electrical length of a feeder line are adjusted by changing the on-load voltage of the on-load variable capacitance diode, and the purpose that the center frequency is adjustable is achieved. In addition, three transmission zeros are introduced by source load coupling, so that the electric adjusting power divider has high selectivity and is also good in stopband suppression effect.

The present invention discloses a broadband high-selectivity balanced band-pass filter based on multimode resonators. The band-pass filter comprises an input port feeder, a first output port feeder, a second output port feeder, a first multimode resonator and a second multimode resonator which are arranged on the upper surface of a dielectric substrate, and a metal earth plate arranged on the lower surface of the dielectric substrate, wherein both the first and second multimode resonators are symmetric stub-loaded multimode resonators; wherein the input port feeder comprises symmetrically connected first and second input port feeders; the first multimode resonator comprises two quarter-wave resonators, and three open-ended symmetric loading units; the second multimode resonator comprises two quarter-wave resonators, and three open-ended symmetric loading units. The broadband balanced band-pass filter according to the present invention has advantages such as broad stopband, minimized size, high common-mode rejection, high selectivity and low costs, and is quite suitable for modern wireless communication systems.

The invention discloses an LTCC (low temperature co-fired ceramic) wide-stop band band-pass filter. The filter comprises three 1 / 4-wavelength short-circuit stepped-impedance resonator with different shapes on different layers, wherein the three resonators are staggered in an LTCC substrate and formed by combining short-circuit stepped-impedance resonators loaded on adjacent layers with capacitor chips respectively; and the three resonators have the same fundamental frequency and different secondary harmonics and higher harmonic frequencies. Through the invention, the structural characteristics of LTCC are made full use in the arrangement of the resonators so that the three resonators are positioned on different circuit layers respectively, staggered distribution is realized, and the circuit volume is reduced; moreover, the 1 / 4-wavelength resonators have the same fundamental frequency and different shapes and higher harmonic frequencies, the parasitic passband of the filter is effectively suppressed, and the stop band property of the filter is improved. The invention is suitable for the microwave filtering circuits.

The invention discloses a compact broadband microstrip antenna with harmonic suppression. The antenna comprises a single-layer dielectric substrate, and an antenna unit arranged on the dielectric substrate. The antenna unit comprises a rectangular patch, two quarter-wavelength resonators and a ground short-circuit pin. The first quarter-wavelength resonator and the second quarter-wavelength resonator are unequal in length and unequal in width and parallel to the radiating side of the rectangular patch, the ground short-circuit pin is inserted between the two quarter-wavelength resonators, andthe rectangular patch is excited by coupling feeding. The feeding point of the antenna is arranged on one quarter-wavelength resonator and fed by a copper axis probe; the rectangular patch in the antenna element is an ordinary patch antenna, and the first and second quarter-wavelength resonators have two resonant points offset from the center frequency, but do not participate in radiation. The antenna of the invention has the advantages of low cross section and simple structure, effectively increasing the antenna band width, and simultaneously having the advantages of high harmonic suppression.

A printed bandpass filter is mounted on a precision substrate to eliminate the need for post-fabrication tuning. The filter input is capacitively coupled to a series of quarter wavelength resonators and the filter output. The quarter wavelength resonators are printed as spirals to reduce filter size. The resonators define the bandpass characteristics of the filter. The filter also weakly couples the input signal to the filter output in a manner to cancel the signal image. Mechanical clips mitigate thermal stress on solder connections when the precision substrate mounted on a second printed circuit board.

The invention discloses a band-pass filter based on 5G double-frequency dielectric integrated suspension lines. The band-pass filter comprises five dielectric plates which are sequentially arranged into five layers from top to bottom, the front and back surfaces of the dielectric plates being provided with metal circuits; the middle portions of the second dielectric plate and fourth dielectric plate which are distributed from the top to the bottom are of hollow structures, so that two air cavities for metal shielding can be formed; filter circuits formed by transmission lines are arranged on the upper layer and lower layer of the third dielectric plate; and the transmission lines comprise a G5-layer metal conductor transmission line and a G6-layer metal conductor transmission line, whereinthe G5-layer metal conductor transmission line is a pair of symmetrically arranged U-shaped resonators used as feeder lines, and the G6-layer metal conductor transmission line comprises two quarter wavelength hairpin type resonators used for generating a first transmission frequency band, two quarter wavelength resonators, and two symmetrically arranged capacitance loading stubs. According to theband-pass filter of the invention, an extra zero point can be generated through an electromagnetic coupling separation effect, and a high-isolation and high-selectivity circuit result is realized.

The invention discloses a miniature triple-band band-pass filter based on embedded quarter-wavelength resonators, comprising two embedded quarter-wavelength resonators arranged symmetrically, two split-ring resonators, two 0-degree tap feeders, and a metalized via V arranged between the two embedded quarter-wavelength resonators. Through mutual offset of magnetic coupling and electric coupling and by adoption of the 0-degree tap feeder structure, the selectivity and the degree of isolation between pass bands of the filter are improved greatly. The miniature triple-band band-pass filter of the invention has the advantages of low weight, small size, high reliability, excellent performance, good temperature stability, mass production, low cost and the like, and is applicable to multi-band multi-service wireless communication systems in different working environments.

The invention discloses an LTCC filter for the coupling inhibition of third and fifth harmonics based on frequency selectivity, and the filter comprises two quarter-wave resonators, two feed lines, and a plurality of floor layers, wherein the two quarter-wave resonators, the two feed lines and the plurality of floor layers are respectively distributed on ten conductor layers, and all layers are connected with each other through metal through holes. The first, third, fifth, eighth and tenth layers are floors, the second, fourth, sixth and ninth layers are circuit layer, and the seventh layer is a layer where a feed circuit is located. The feed line between the two feed lines and the resonator at the sixth layer is achieved in a mode of parallel coupling, and coupling regions between the two feed lines and the resonators are selected for inhibiting third and fifth harmonics, thereby achieving a wide stop band. The two quarter-wave resonators achieves the coupling between a part of branch nodes, thereby achieving a wide stop band filter which inhibits third and fifth harmonics. The LTCC technology employed by the invention employs a multi-layer structure, and reduces the size of the filter.

Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

The invention discloses a miniature dual-band band-pass filter with an adjustable low band, the miniature dual-band band-pass filter comprises an upper layer micro-band structure, a middle layer medium substrate and a lower layer grounded metal sheet. The filter comprises two resonators and two feeder lines; the centers of the two resonators are symmetric; and each resonator comprises a main transmission micro-band line with both ends being short-circuited, an open-circuit branch line which is loaded at the middle point of the main transmission line, a varactor and a capacitor. When the resonators work under the low band, the resonators being one fourth wavelength are corresponded to; and when the resonators work under a high band, the resonators being one second wavelength are corresponded to. One sides of the feeder lines are coupled with the resonators to feed power, and the other sides of the feeder lines are directly lapped on the resonators to feed power. The miniature dual-band band-pass filter with the adjustable low band has the characteristics that: the central frequency of the low band is adjustable while the high band remains unchanged.

The invention discloses a plane miniaturization communication band-pass filter with a broadband external inhibition characteristic. The band-pass filter with the broadband external inhibition characteristic is realized according to the structure of a plane substrate integrated coaxial line by adopting a quarter-wave resonator as a resonance unit through a partial coupling mode. The miniaturization band-pass filter which is low in loss, has the broadband external inhibition characteristic and can be integrated with a plane radio frequency microwave circuit is realized by the invention by aiming at the development requirements of plane integration and miniaturization wireless communication equipment. The miniaturization band-pass filter has the advantages that the structure is simple, the size is small, the requirement of plane circuit integration is met, the cost is low, the mass production is convenient and the like. Meanwhile, the filter has the broadband attenuation inhibition characteristic outside a passband.

The invention discloses a binary-type bandwidth reconfigurable band-pass filter, relates to a strip-shaped line filter, and belongs to the technical field of basic electrical elements. The filter is arranged on a dielectric substrate, and is mainly composed of an input transmission line, an output transmission line, N quarter-wavelength resonators, and N+1 parallel coupling structures which are formed by end-connected switchable metal strip strips. The M end-connected switchable metal strip strips which are arranged in sequence are arranged in the center of each parallel coupling structure, and the two ends of each end-connected switchable metal strip are connected with PIN diode switches respectively, and are grounded through via holes, so that a bias voltage can be applied to PIN diodesthrough resistors which are vertically welded to the centers of the strips, and two ends of the metal strips can be switched between two states of open circuit and short circuit. The 2M groups of coupling coefficients can be realized through M control voltages, so that the bandwidths of the 2M filters can be realized, that is, the binary-type bandwidth reconfigurable band-pass filter is achieved.

The invention discloses a substrate-insertion type rectangular waveguide band elimination filter, which belongs to the field of microwave band elimination filter. The filter is characterized in that two cavities fold to form a rectangular waveguide transmission line; a slot for inserting a medium substrate is arranged at the folding part of any one cavity; the medium substrate is electrically connected with the corresponding cavity through metal conduction bands arranged at two sides of the medium substrate and is pressed and fixed by folding of the two cavities; a plurality of L-shaped quarter-wave resonators are arranged on any one surface of the medium substrate; and each resonator is coupled with the rectangular waveguide transmission line so as to generate a stop band. According to the invention, the substrate-insertion type rectangular waveguide band elimination filter has a simple structure, does not need to use an external waveguide resonator, has low difficulty in processing and assembly and is small in volume and low in cost.

The invention discloses a microstrip fed harmonic suppression broadband patch antenna with a compact structure. The broadband patch antenna comprises a single-layer microwave dielectric substrate, a rectangular radiation patch with a working frequency of f1, two quarter-wavelength resonators with a working frequency of f2, two quarter-wavelength resonators with a working frequency of f3, two short-circuit pins with a radius of r and a feeding microstrip line, wherein the rectangular radiation patch with the working frequency of f1 is located at the center of the whole structure; the two quarter-wavelength resonators with the working frequency of f2 share one short-circuit pin with the radius of r, are in near-coupling with a radiation edge of the rectangular radiation patch and are connected with the microstrip line to realize a feeding structure; and the two quarter-wavelength resonators with the working frequency of f3 share one short-circuit pin with the radius of r and are in near-coupling with another radiation edge of the rectangular radiation patch. The bandwidth of the patch antenna is effectively increased, high-order harmonic waves can be effectively suppressed, and the broadband patch antenna is compact and simple in structure, low in profile and easy to implement.

The invention discloses an adjustable dual-frequency band-pass filter with independent power. The filter comprises a dielectric plate, an earth plate, a first quarter-wave resonator, a second quarter-wave resonator, short-circuit stub-loaded resonators, an input feeder line, an output feeder line and an external circuit, wherein the first quarter-wave resonator, the second quarter-wave resonator, the short-circuit stub-loaded resonators, the input feeder line, the output feeder line and the external circuit are all arranged on the upper surface of a dielectric substrate; the earth plate is arranged on the lower surface of the dielectric substrate; the short-circuit stub-loaded resonators are symmetrical left and right around the central shaft of the filter; the first quarter-wave resonator and the second quarter-wave resonator are symmetrical left and right around the central shaft of the filter; and the input feeder line and the output feeder line are symmetrical left and right around the central shaft of the filter. The adjustable dual-frequency band-pass filter has the advantages of light weight, small volume, high reliability, excellent performance, high temperature stability, low production cost and the like, and can be applicable to multi-band multi-service modern wireless communication systems under different working environments.

The invention relates to a planar CQ (Cascade Quadruplet) band-pass filter which is made on a double-sized copper-coated micro-strip plate by a mode of a printed circuit board. An input end feeding head port 1 for inputting an electromagnetic wave signal, an output end feeding head port 2 for outputting the electromagnetic wave signal, a first port feeding line, a second port feeding line, a first half-wavelength micro-strip resonator, a fourth half-wavelength micro-strip resonator, a second quarter-wavelength micro-strip resonator, a third quarter-wavelength micro-strip resonator and a grounding through hole are respectively made on the same surface of the double-sized copper-coated micro-strip plate, and a copper-coated grounding plate is arranged on the other surface of the micro-strip plate. The planar CQ band-pass filter is formed by cascading the two half-wavelength resonators and the two quarter-wavelength resonators, so that the filter can have simple controlled functions of electric coupling and magnetic coupling when the filter has small volume; crossed coupling is introduced among the resonators, two transmission zero points can be generated at the two sides of a pass band of the filter, the frequency selectivity and out-of-band rejection of the filter are improved, and the planar CQ band-pass filter has the advantages of good frequency selectivity, low insertion loss, small volume and a simple structure.