185results about How to "High out-of-band rejection" patented technology

The invention provides a filtering antenna, which comprises an upper medium substrate, a connecting mechanism and a lower medium substrate, wherein the upper medium substrate, the connecting mechanism and the lower medium substrate are sequentially overlapped, a plurality of first metallic through holes are formed in the upper medium substrate, a plurality of second metallic through holes are formed in the lower medium substrate, a first metal layer and a second metal layer are respectively arranged at the upper surface and the lower surface of the upper medium substrate, a third metal layer and a fourth metal layer are respectively arranged at the upper surface and the lower surface of the lower medium substrate, a single-mode rectangular resonance cavity is surrounded by the first metal layer, the second metal layer and the first metallic holes, a double-mode rectangular resonance cavity is coupled and cascaded with the single-mode rectangular resonance cavity, and two parallel irradiating gaps are formed in the first metal layer, and are symmetric to the center of a middle point of a projection of the single-mode rectangular resonance cavity on the first metal layer. The filtering antenna has the beneficial effects of high out-of-band inhibition and low crossing polarization.

The invention relates to a Ku-wave band and ultra-narrow band micro band-pass filter with low loss and high inhibition, which comprises an input / output interface, four parallel resonant units, a Z-shaped cross coupling circuit and an input and output inductor, wherein the input / output interface is suitable for surface mounting; the four parallel resonant units are realized by adopting two layers of folded coupling strip lines; and the structures are realized by adopting a multi-layer low-temperature co-fired ceramic (LTCC) process technology. The invention has the advantages of good band-passselectivity, good out-of-band inhibition, low insert loss, light weight, small volume, high reliability, good electrical performance, good phase frequency characteristic linearity, good temperature stability, good electrical performance batch consistency, low cost and the like, can realize large batch production, and is especially suitable for wireless communication handheld and portable terminalproducts such as radars, communication terminals, rocket-borne terminals, air-borne terminals, missile-borne terminals, space ships, individual mobile communication terminals and the like, and corresponding frequency band systems with strict requirements on volume, weight, electrical performance, reliability and the like.

The invention relates to an L wave band miniature band pass filter with low loss and high suppression, which comprises a surface-mounted input / output interface, five parallel resonance units achieved by adopting three layers of folded and coupled strip lines, four zero setting circuits and an input and output inductor, which are all achieved by adopting a multi-layer low temperature co-fired ceramic technology. The invention has the advantages of small volume, light weight, high reliability, excellent electrical performance, good phase-frequency characteristic linearity, good temperature stability, good bulk electrical performance consistency, low cost, mass production and the like, and is particularly suitable for radar, communication, rocket-bearing, airplane-bearing, missile-bearing, spacecrafts, one-man mobile communication terminals and other handheld and portable radio communication terminal products, as well as corresponding band systems which are serious about volume, weight, electrical performance and the like.

The invention discloses a TM mode dielectric filter. The TM mode dielectric filter comprises a base and a covering plate, wherein at least two resonators are arranged in the base; frequency adjustment holes are formed in the resonators, and a resonator coupling device is arranged between every two adjacent resonators; the covering plate is provided with frequency adjustment screw rods corresponding to the frequency adjustment holes; the two resonators at the two ends in the base are respectively provided with an input and output coupling device. The TM mode dielectric filter is characterized in that resonators are cylindrical, and the resonators and the base are made of the same material and formed integrally; annular air grooves with upper ends open are formed circumferentially in the cylindrical surface of each resonator in the base; the base and the covering plate are made of TM mode dielectric material. The TM mode dielectric filter has the advantages of being simple in structure, free of introduction of elastic conductors, small in size, and better in filtering performance.

The invention relates to an acoustically coupled thin-film BAW filter, comprising a piezoelectric layer, an input-port on the piezoelectric layer changing electrical signal into an acoustic wave (SAW, BAW), and an output-port on the piezoelectric layer changing acoustic signal into electrical signal. In accordance with the invention the ports include electrodes positioned close to each other, and the filter is designed to operate in first order thickness-extensional TE1 mode.

The invention discloses an aperture multi-layer structure-based high-out-of-band rejection frequency selective material design method. The method includes the following steps that: (1) a frequency selective material is designed based on an aperture multi-layer structure, wherein the aperture multi-layer structure includes three layers of structures, namely, a top-layer patch, a bottom-layer patch and a middle coupled aperture layer; (2) an out-of-band transmission null characteristic is realized through constructing a design method of patch displacement of the top-layer patch and the bottom-layer patch, and the side band cut-off characteristic of the aperture multi-layer structure-based frequency selective material can be further improved; and (3) a unit interdigital technology is adopted to carry out miniaturization processing on the surface of the frequency selective material, so that the unit size of the surface of the frequency selective material can be decreased. With the method of the invention adopted, a high-order coupling characteristic is realized, and the side band cut-off performance of the frequency selective material can be improved; and the unit interdigital method is adopted, so that the unit size of the surface of the frequency selective material can be decreased, and angle stability under the incoming of electromagnetic waves can be improved; and the out-of-band rejection ability of the frequency selective material is stronger, and the pass-band edge rise performance and sharp drop performance of the frequency selective material are better.

The invention provides a gallium arsenide dual-mode band-pass filter and a manufacturing method of the gallium arsenide dual-mode band-pass filter. According to the filter, the requirement for a miniaturized millimeter-wave circuit is met, the insertion loss is small, and the selectivity is high. According to the technical scheme, a loading branch and a lambda / 2 resonator constitute a bent branch line loading type dual-mode resonator of an annular structure; microwave signals fed through an input micro-strip are transmitted to an output micro-strip through two physical channels of the filter, so that frequency selection of a pass band is achieved, wherein according to one channel, the signals are transmitted through an input coupling branch and an output coupling branch, an extra out-of-band transmission zero is provided, and the position of the zero is adjusted through the lengths and the coupling distances of the input coupling branch and the output coupling branch, and according to the other channel, the microwave signals are coupled to the dual-mode resonator through an incoming feeder and then are coupled to the output micro-strip through the dual-mode resonator, two transmission pole pass bands and two transmission zero stop bands are formed by the dual-mode resonator, and one of the transmission pole pass bands and one of the transmission zero stop bands are provided by a dual module of the dual-mode resonator.

The invention relates to an acoustically coupled thin-film BAW filter, comprising a piezoelectric layer, an input-port on the piezoelectric layer changing electrical signal into an acoustic wave (SAW, BAW), and an output-port on the piezoelectric layer changing acoustic signal into electrical signal. In accordance with the invention the ports include electrodes positioned close to each other, and the filter is designed to operate in first order thickness-extensional TE1 mode.

The invention discloses a broadband dual-polarized filtering dipole antenna without an additional circuit, which is characterized in that two pairs of mutually perpendicular radiation array sub-arms are printed on a horizontal dielectric substrate, and the two pairs of mutually perpendicular radiation array sub-arms are horizontally placed; two vertical dielectric substrates are respectively equipped with baluns to feed the radiation array sub-arms, and the balun includes a slot line, two closed stubs and an inverted L-shaped feeder line with the tail end being open-circuited; the two vertically intersecting vertical dielectric substrates are arranged on a reflecting plate; the closed stubs are close to the middle position of the vertical dielectric substrates on the top and connected withthe radiation array sub-arms on the horizontal dielectric substrate through extending upwards so as to constitute a short-circuit inverted L-shaped resonator together; and the horizontally placed radiation array sub-arms and the part which does not extend upward at the top of each closed stub constitute resonant groove together. The invention realizes a broadband filtering antenna operating at 1.7-2.8GHz, and has the excellent performance such as high isolation, weak cross polarization and good filtering and radiation characteristics.

The invention relates to a medium filter, which comprises a cavity (210) and a medium resonator (220), wherein the medium resonator (220) is fixed on the cavity (210); the medium resonator (220) comprises a columnar medium body; the middle of the medium resonator (220) is provided with a through hole (222); one end face of the columnar medium body is provided with an end face electrode (223) and a coupling electrode (224); the end face electrode (223) is positioned around the through hole (222); the coupling electrode (224) is separated from the end face electrode (223); the outer surface (225) of the columnar medium body is covered by a protective layer (25), a metal layer (226), the end face electrode (223) and the coupling electrode (224); the protective layer (225) is positioned on the end face of the columnar medium body which is provided with the end face electrode (223) and the coupling electrode (224); and the metal layer (226) is covered on the peripheral surface of the columnar medium body, and is separated from the coupling electrode (224). The medium filter is easy for realizing transmission zero points, out-of-band rejection is increased, and the Q value is increased.

The invention relates to a coupling method of a microstrip filter and a microstrip resonator thereof. The resonator comprises a group of finger-inserting capacitors comprising microstrips, a group of double-helix curved inductors and a group of blocky capacitors formed with ground, wherein the microstrip comprises an upper-layer superconducting film, a lower-layer superconducting film and an artificial monocrystal medium positioned between the upper-layer and the lower-layer superconducting films; the finger-inserting capacitors are connected in parallel with the double-helix curved inductors, and the finger-inserting capacitors and the double-helix curved inductors connected in parallel are serially connected with the blocky capacitors; a line in the finger-inserting capacitors of the first resonator, which has the same charge polarity with an outermost line of the finger-inserting capacitor of the second resonator is shortened or cut off completely; and the outermost line of the finger-inserting capacitors of the second resonator is elongated and bent, extends into a line shortened or cut off completely in the finger-inserting capacitors of the first resonator and is coupled with two adjacent lines in the finger-inserting capacitors of the first resonator. The filter has less insertion loss, large out-band rejection, high band-edge gradient and good group delay performance.

The invention relates to a C-band low-loss and high-inhibition micro band-pass filter which comprises an input interface and an output interface which are applicable to surface installation, five parallel resonance units realized by adopting two layers of folded coupling strip lines, four zero-point setting circuits, an input inductance and an output inductance, wherein the structures are realized by adopting a multilayer low-temperature co-fired ceramic process technology. The micro band-pass filter of the invention has the advantages of small volume, light weight, excellent electrical performance, high reliability, good linearity of phase-frequency characteristic, good temperature stability, fine batch consistency of electrical performance, low cost and the like, is suitable for mass production, is especially applicable to hand-hold and portable finished products for wireless communication, such as radars, communication, arrow loading, sky borne, missile borne, space ships, one-man mobile communication terminals, and the like as well as corresponding frequency range system with rigorous requirements on volume, weight, electrical performance, reliability and the like.

The invention discloses a multimode wide-band filter based on a multi-branch loaded square resonance ring, which mainly solves the problem that the circuit size of a conventional multimode wide-band filter is limited by the area of the resonance ring. The filter comprises a micro-band dielectric substrate (1), a metal grounding plate (2), a square resonance ring (3) and a pair of input and output feed lines (8). The square resonance ring (3) comprises a square metal ring (4), a pair of equilong perturbation branches (5), a pair of impedance matching metal pieces (6), and a pair of transmission zero point branches (7). The two equilong perturbation branches (5) are located at a pair of external opposite angles of the square metal ring (4). The two same impedance matching metal pieces (6) are located at the other pair of opposite angles of the metal ring (4). The transmission zero branches (7) and the equilong perturbation branches (5) are connected in parallel or located in the metal ring (4) and are connected with the inner edge of the metal ring (4). The pair of input and output feed lines (8) is symmetrically arranged above the micro-band dielectric substrate (1) horizontally, and is parallel to the tail ends of the perturbation branches. According to the multimode wide-band filter, the circuit size of the filter is reduced, and the circuit is miniature, and the filter can be applied to wireless communication systems.

The invention provides a three-dimensional integrated subminiature band-pass filter which is realized by adopting a semi-lumped structure, and comprises an input / output port, four parallel resonant cells, an inter-stage coupling capacitor and a Z-shaped crossed coupling capacitor. According to the band-pass filter provided by the invention, interconnection between stages is realized by virtue of electromagnetic coupling among the resonant cells. By virtue of an LTCC (low temperature co-fired ceramic) laminating structure, an equivalent lumped parameter element is realized. Compared with the prior art, the three-dimensional integrated subminiature band-pass filter has the advantages of a small size, low cost, good frequency-selection characteristic, high temperature stability and small insertion loss, can be machined into a paster film, is convenient to integrate with other microwave assemblies and beneficial to mass production. The scheme adopted by the invention can be used for inhibiting out-of-band harmonic waves, and is applicable to occasions and corresponding systems with strict requirements on size, electrical performance, temperature stability and reliability, such as communication terminals of corresponding microwave millimeter wave frequency bands, digital radars and wireless communication hand-held terminals.

The invention relates to a low-temperature co-fired ceramic ultra-wideband micro filter, comprising input and output interfaces suitable for pasting on a surface; input and output inductors; nine parallel resonance units implemented by three-layer folded coupling strip line and comb type coupled resonance structures; and eight groups of enhanced coupling diaphragms with resonance levels which are directly connected with each other, the structures are implemented by multi-layer low-temperature co-fired ceramic technology. According to the invention, the low-temperature co-fired ceramic ultra-wideband micro filter has the advantages of wide frequency coverage, low insertion loss, good controllability, small volume, light weight, high reliability, good electrical property, good phase frequency characteristic linearity, good temperature stability, low cost and mass production, and is particularly applied to fields of millimeter wave communication, microwave navigation, guidance, telemetry, remote control, satellite communication and military confrontation, and corresponding frequency range systems having excessive demand on volume, weight, electrical property and reliability.

The invention discloses a high-rejection LTCC (low temperature co-fired ceramic) low-pass filter which comprises an input terminal, an output terminal and a grounding terminal. Out-of-band rejection of the filter is improved by adding a transmission zero outside a band, and reactance elements are connected according to a certain topological structure by the aid of LTCC multilayer ceramic technology to achieve functions of the low-pass filter. A filter packaging structure is a standard 1206 packaging structure, and grounding layers inside the filter are connected through a weldable conductor printed by the side face of an LTCC substrate to form a grounding electrode of the filter. The low-pass filter has the advantages of small size, low cost, low insertion loss, high out-of-band rejection, fine temperature stability, convenience in use and the like, and batch production is facilitated.

The invention discloses a multilayered structure integrated filter antenna based on a filter Balun, and mainly solves the problem that the volume of the filter antenna of a traditional monolayer micro-strip structure is larger. The multilayered structure integrated filter comprises a dielectric substrate, a filter part and a radiation unit, wherein the dielectric substrate comprises two micro-strip dielectric substrates and a metal ground; the filter part comprises an input port, the filter Balun positioned on the left sides of the dielectric substrates and two output ports connected with thefiler part; the filter Balun comprises two face-to-face C-shaped second-order stepped impedance resonators etched on the upper dielectric substrate and two back-to-back C-shaped second-order stepped impedance resonators etched on the upper surface of the lower dielectric substrate; the radiation unit is etched on the upper surface of the upper dielectric substrate, and comprises two micro-strip lines, two butterfly printing dipoles and a director. The multilayered structure integrated filter antenna has the advantages of compact structure, wide bandwidth, high frequency edge selectivity and good out-of-band rejection, and can be used for the radio frequency front end of a wireless communication system.

The invention provides a waveguide coupling micro-strip / band-shaped line filter, comprising a cover board for a shielding box in a microwave transceiving module, a microwave mixing circuit board, a base plate for the shielding box, a plate for a filter and a cover board for the filter, wherein the plate for the filter is separated from the microwave mixing circuit board and is coupled with the microwave mixing circuit board in a waveguide way, that is, the cover board for the shielding box is provided with two rectangular waveguide openings, the plate for the filter is provided with a micro-strip or strip-shaped line-waveguide converter corresponding to the microwave mixing circuit board; and a signal on the microwave mixing circuit board is coupled to the plate for the filter through the strip-shaped line-waveguide converter, and microwave mixing circuit board is filtered, strip-shaped line-waveguide converted and coupled so as to realize the micro-strip filter function. The waveguide coupling micro-strip / band-shaped line filter has the advantages of improving the maintainability, producibility and debugging performance of the product, improving the spurious suppression, solving the problems of microwave transmission line and the power cord intersection in the routing process of the double-surface circuit board, and improving the performance of the product.

The invention discloses a dielectric dual-mode band-pass filter based on a patch structure. The dielectric dual-mode band-pass filter comprises a cavity, wherein a dielectric resonator is placed at the central position of the cavity, the upper end and the lower end of the dielectric resonator are connected with the cavity, a first metal patch and a second metal patch are pasted on the outer side surface of the dielectric resonator, the transverse central line of the first metal patch is perpendicular to the transverse central line of the second metal patch, the first metal patch and the second metal patch are used for controlling resonant frequencies of two resonant modes of the dielectric resonator, the dielectric resonator is pasted with a third metal patch at a magnetic field distribution overlapped position of the two resonant modes, and the third metal patch is used for controlling coupling strength between the two resonant modes of the dielectric resonator. The dielectric dual-mode band-pass filter disclosed by the invention is simple in structure and is convenient to implement; and the metal patches are pasted at different positions of the same dielectric resonator, and thus, frequency control of the resonant modes can be achieved by adjusting the sizes of the metal patches.

The invention discloses a miniature C-band band-pass filter with low insertion loss and excellent high-order harmonic suppression, which comprises an input port, an output port, an input inductor, an output inductor, an input capacitor, an output capacitor, five parallel resonance units, four zero set units, two cross-coupled capacitors and the like. All components comprise more than two layers and are realized by low-temperature co-fired ceramic technology, the input inductor, the output inductor, the input capacitor and the output capacitor are in a strip line design according to distributed parameters, intervalve inductors and intervalve capacitors adopt space coupling and distributed parameters, the cross-coupled capacitors are dielectric tablet 'Z'-shaped capacitors, and all the five parallel resonance units are in a three-layer folding and coupling strip line design. The band-pass filter of a stacked structure based on the low-temperature co-fired ceramic technology has the advantages of small size, light weight, high reliability, low insertion loss, excellent high-order harmonic suppression and the like, and meets the requirements of fields such as electronic communication and the like on miniaturization and integration of the electronic components.

The invention relates to a low-loss high-suppression minitype cavity body band-pass filter which comprises 50 ohmic impedance input / output interfaces suitable for surface mounting, five parallel resonant units and input and output inductors, wherein the five parallel resonant units are realized by adopting a distributed parameter cylindrical cavity body coupling structure; and the 50 ohmic impedance input / output interfaces, the five parallel resonant units as well as the input and output inductors are realized by adopting a multilayer low-temperature co-fired ceramic technology. The low-loss high-suppression minitype cavity body band-pass filter provided by the invention has the advantages of good band-pass selectivity, good out-of-band suppression, lower insertion loss, small volume, light weight, high reliability, good electric property, good phase frequency characteristic linearity, good temperature stability, good electric property batch consistency, low cost, volume production and the like, and is especially suitable for wireless communication hand-held and portable terminal products of radars, correspondence, rocket carrying, aircraft carrying, missile carrying, spacecrafts, individual soldier mobile communication terminals and the like, as well as places and corresponding frequency band systems which have rigor requirements in volume, weight, electric property, reliability and the like.

A dielectric filter comprises four cube-like dielectric resonators with a metal conductive layer attached to an outer surface of a ceramic dielectric, wherein the four dielectric resonators are connected in a straight line sequentially and fixedly. The front and rear dielectric resonators are single-mode dielectric resonators, and the middle two dielectric resonators are three-mode dielectric resonators. The edges of the three-mode dielectric resonators are provided with tangent angles which can generate cross-coupling. A pair of main coupling windows and a pair of cross-coupling windows are arranged between each single-mode dielectric resonator and the adjacent three-mode dielectric resonators. Each of the three-mode dielectric resonators and the single-mode resonator can produce two transmission zeros, which can improve the out-of-band rejection of the filter and the filtering performance of the filter. At the same time, it provides technical support for the adjacent arrangement of two three-mode dielectric resonators to reduce the volume of the filter.

The invention relates to a cross-coupling dielectric waveguide filter, which comprises a ceramic dielectric body. A metal shielding layer is formed on the outer side of the ceramic dielectric body through metallization; a plurality of groups of resonance holes are formed in the surface of one side of the ceramic dielectric body; and each group of resonance holes comprises two resonance blind holeswhich are symmetrically formed. A through groove running through the ceramic dielectric body is formed between every two groups of resonant holes, and a plurality of resonant cavities are separated by the through grooves; the dielectric body is also provided with a plurality of coupling blind holes with adjustable sizes; a coupling window is formed between every two groups of resonance holes; andat least one through groove is an arc-shaped through groove and is matched with one coupling blind hole to form a cross coupling zero point. According to the invention, the problem of high rectangularity of the filter is solved; the integrated structure of the ceramic dielectric body is beneficial to miniaturization and consistency; and the arc-shaped through groove is formed in the resonant cavity in the dielectric body, and the position of the cross coupling zero point can be changed by adjusting the radian and the arc length of the arc-shaped through groove, so that out-of-band rejection is improved, and the influence on other communication frequency bands is reduced.

The invention discloses a receiver front-end circuit with an external linearity enhanced current mode structure. The receiver front-end circuit comprises an input low-noise transconductance amplifier,a band-pass filter, a first passive mixer, a first transimpedance amplifier, a first output buffer stage circuit, a second passive mixer, a second transimpedance amplifier and a second output bufferstage circuit. The current mode radio frequency front-end circuit solves the problem that the out-of-band linearity of an existing current mode radio frequency front-end circuit becomes poor.

The invention discloses an elliptic function type high-pass filtering channel, which comprises a cavity and a cover plate, wherein the cavity is provided with a lengthwise hollow cavity; a plurality of conductor rods which are sequentially and capacitively coupled are arranged along a lengthwise direction linearity of the hollow cavity; the conductor rods at two ends of the lengthwise direction are respectively and capacitively coupled with two connection ports arranged on the cavity; ends for realizing capacitive coupling are arranged between the adjacent conductor rods and / or the conductor rods and one connection ports; a sleeve is formed by a first end and a core column is formed by a second end; a core column of the second end is placed in the sleeve of the first end to form an open circuit coaxial cable, so as to realize the capacitive coupling; a coupling element is further arranged between the first end and the second end; the coupling element is a sheet-shaped medium piece which has two sides covered by conductive layers and is used for the core column to pass through; the two conductive layers are respectively connected with the first end and the second end. The high-pass filtering channel has the characteristics of simple structure, convenience for tuning, wide pass band, small insertion loss, high out-of-band suppression degree and the like.

The embodiment of the invention discloses an active power filter, a duplexer, and wireless communication equipment. The active power filter comprises a first filter, a first amplifier, a second filter, a down converter, a third intermediate-frequency filter, a second amplifier, a fourth intermediate-frequency filter, an up converter, a fifth radio frequency filter, and a voltage-controlled oscillator which is used for providing local oscillation signals to the down converter and the up converter, wherein the input end of the first amplifier is connected with the output end of the first filter while the output end of the first amplifier is connected with the input end of the second filter; the output end of the second filter is connected with the input end of the third intermediate-frequency filter through the down converter; the output end of the third intermediate-frequency filter is connected with the input end of the second amplifier; the output end of the second amplifier is connected with the input end of the fourth intermediate-frequency filter; and the fourth intermediate-frequency filter is connected with the input end of the fifth radio frequency filter through the up converter. By virtue of the scheme, multiple excellent performance indexes of the filter can be taken into consideration conveniently.

The invention provides an E-surface superconducting diaphragm millimeter wave waveguide filter which aims to overcome the defects that in an existing E-surface diaphragm millimeter wave filter structure, when E-surfaces are inserted among resonant cavities, the machining difficulty is large, it is difficult to fix the specific position, superconducting substrates are prone to breaking and the difficulty in filter assembling is large. Two or more superconducting diaphragms are fixed to rectangular waveguide central E-surfaces, and the superconducting diaphragms are coupled to rectangular waveguides to form resonant cavities; adjacent superconducting diaphragms are distributed at unequal intervals, and the adjacent superconducting diaphragms are coplanar in the length direction of the rectangular waveguides; the rectangular waveguides are formed by relatively fixing two waveguides with the sections being in a right-angled U shape, and the connection faces of the right-angled-U-shaped waveguides are the central E-surfaces of the formed rectangular waveguides for fixing the superconducting diaphragms; the coupling coefficients of the resonant cavities can be adjusted by adjusting the width of the superconducting diaphragms; the central frequency of the filter can be changed by changing the size of the rectangular waveguides. The E-surface superconducting diaphragm millimeter wave waveguide filter has the advantages that the insertion loss is small, the out-band suppression degree is high, and the rectangular waveguide structure is easy to assemble.

A method and system for transmitting data in a wireless network. The method includes generating a plurality of waveforms corresponding to a plurality of frequency subbands for a predetermined frequency band. The predetermined frequency band is divided into a plurality of groups of subbands, and the plurality of groups of subbands being divided into the plurality of frequency subbands. Additionally, the method includes receiving a data signal, processing information associated with the received data signal, modulating the plurality of waveforms based on at least information associated with the received data signal, and transmitting the modulated plurality of waveforms. Any two of the plurality of waveforms are substantially orthogonal to each other. Each of the plurality of waveforms corresponds to a waveform frequency spectrum associated with a spectral amplitude as a function of a frequency.

The invention provides a filter comprising an input port, an output port, a shield case, a medium, at least two layers of half-wavelength resonant cells, at least one layer of quarter-wavelength resonant cell, and at least three layer of grounded resonant cells. The half-wavelength resonant cells and the quarter-wavelength resonant cell are connected in parallel between the input port and the output port. The input port is connected with the first layer of half-wavelength resonant cell, and the output port is connected with the last layer of half-wavelength resonant cell. Each half-wavelength resonant cell is suspended at both ends. One end of the quarter-wavelength resonant cell is grounded through the shield case, and the other end is suspended. The grounded resonant cells surround the half-wavelength resonant cells and the quarter-wavelength resonant cell respectively. Inner sides of the grounded resonant cells are suspended and outer sides are grounded through the shield case. The invention also provides a filtering method.

The embodiment of the invention discloses a small dielectric dual-mode filter without a shell, and belongs to the technical field of communication. The filter comprises n resonant cavities connected in series through a metal rod, wherein a metal sheet is arranged between every two adjacent resonant cavities, the first resonant cavity and the last resonant cavity in the n resonant cavities are metal resonant cavities, the remaining n-2 resonant cavities in the n resonant cavities are dielectric dual-mode resonant cavities, the dielectric dual-mode resonant cavities are of a symmetrical polygonal structure, metallization of the surfaces of the dielectric dual-mode resonant cavities is achieved, and the n resonant cavities are coupled through coupling windows on the metal sheets. According tothe filter provided by the embodiment of the invention, a metal shell does not need to be arranged outside the dielectric dual-mode resonant cavity, so that the filter has the advantages of being compact in size, small in loss, large in power capacity, high in out-of-band rejection and good in harmonic performance so as to effectively improve the anti-interference capacity and the frequency spectrum utilization rate of a 5G communication system, reduce the power consumption of the 5G communication system and improve the coverage range of the 5G communication system.