34results about How to "Good out-of-band suppression" patented technology

The invention discloses a substrate integration waveguide high-pass filter. The substrate integration waveguide high-pass filter comprises a half-module substrate integration waveguide high-pass filter and a band rejection filter. The half-module substrate integration waveguide high-pass filter comprises a metal paster, a medium substrate and metal through holes. The metal paster is arranged on the surface of the medium substrate. A rectangular paster is arranged in the middle of the metal paster, the two edges of the metal paster are changed into micro-strip lines through trapezoid micro-strip gradually-changed lines in a transition mode, the micro-strip lines are connected with the input end and the output end respectively, and the row of metal through holes are formed along one side edge in the rectangular paster. The band rejection filter is arranged at the input end of the rectangular paster, and comprises two corner micro-strip branch lines along the micro-strip lines from the input end in sequence. The two corner micro-strip branch lines each comprise a head section and a tail section which are perpendicular to each other to form an L shape. The head sections are vertically connected with the corresponding micro-strip lines, and tail sections are arranged oppositely. The upper sideband of the band rejection filter is the cut-off frequency of the half-module substrate integration waveguide high-pass filter. The filter guarantees good out-of-band rejection, and the return loss in half bandwidth is small.

According to the invention, three technical characteristics are utilized for reducing the size of a resonance cavity. First, a substrate integrated waveguide in an incomplete mode is adopted. Second, a small-size CRME (Circular Ring Miniaturized Element) is loaded on the surface of the resonance cavity so as to excite resonant frequency of lower orders and thus the size of the resonance cavity can be reduced. Third, a feeding mode based on combination of a coplanar waveguide and the CRME is adopted. According to the invention, the ultra-small filter based on the substrate integrated waveguide in the incomplete mode is low in loss and good in frequency selection properties and the size of the filter can be reduced substantially. By the design of the novel CRME, the out-of-band suppression property of the filter is improved substantially. By the design of a single-layer PCB, processing, integration with other planar circuits and cost reduction are facilitated.

The invention provides a dual-passband band-pass filter based on asymmetric coupling lines. The filter comprises a dielectric substrate, a filter positioned on the upper surface of the dielectric substrate, and a metal grounding plate positioned on the lower surface of the dielectric substrate, the filter comprises an H-shaped multi-mode resonator with an improved center, asymmetric parallel coupling lines loaded on the left side and the right side of the multi-mode resonator, stepped impedance branches loaded on the upper side and the lower side of the multi-mode resonator, parallel three-line coupling lines composed of high impedance lines and the parallel coupling lines, and open circuit branches loaded on the lower side of a left port feeder line. According to the invention, under thestrong coupling effect of the multi-mode resonator loaded with a stepped impedance stub and the asymmetric coupling line structure, the selectivity of a passband is improved, and the size of the filter is reduced. The two passbands are low and adjustable in insertion loss, so the filter is good in out-of-band characteristic, compact in structure, low in cost, convenient to process and easy to integrate with other circuits.

A wideband piezoelectric filter with a ladder-type is provided, which is composed of a plurality of first resonators connected in series, a plurality of second resonators connected in parallel, an impedance matching device disposed near the input terminal or the output terminal of the filter, and at least one special parallel ground path led out from serial nodes. The special parallel ground path at least comprises one inductor having a larger inductance value, and a resonator having the same resonant frequency as a serial branch or a capacitor, wherein the larger inductor is connected to the resonator or capacitor in series in the parallel path. The ladder filter according to the invention can have a bandwidth which is more than twice that of the conventional ladder filter, and also has excellent out-of-band rejection characteristics.

The invention relates to a novel double-frequency narrow-band bandpass filter. The novel double-frequency narrow-band bandpass filter comprises a metal microstrip line on the front surface, a medium plate layer, an input port and an output port on the middle part, and a metal plating layer on the rear side of a medium plate, wherein in the metal microstrip line, a resonator consisting of a section of low impedance line and a stepped impedance line connected with the low impedance line, and a novel resonator formed by connecting a quarter wavelength uniform impedance line and a feeder with a rectangular short microstrip line. The resonator structure is symmetrical, so that an odd-even mode theory can be used for analyzing the resonator structure; and the input port and the output port of the feeder are in the same level line. A transmission zero is inserted into a stop band between two pass bands, a zero position in a transmission characteristic curve can be flexibly adjusted, the stop band characteristics are improved, and a transmission zero is inserted outside two center frequencies respectively to improve out-of-band rejection characteristics. The novel double-frequency narrow-band bandpass filter has a simple structure and extremely high frequency selectivity and meets the requirements on miniaturization.

The invention relates to a TM (Transverse Magnetic) mode dielectric resonator for controlling second harmonic migration. The dielectric resonator is a solid step column with a T-shaped longitudinal section; one end of the solid step column is coated with a metal layer or both ends are coated with metal layers; the upper part of the solid step column is provided with a first solid column, and the lower part of the solid step column is provided with a second solid column; the diameter of the first solid column is larger than that of the second solid column; the junction position between the first solid column and the second solid column is provided with a chamfering circular arc area; and the height of the second solid column is larger than 4.5mm. The invention provides the TM mode dielectric resonator which can control second harmonic migration. The dielectric resonator can inhibit a second harmonic wave at the position which is far away from a main frequency band.

The invention discloses a compact type self-resonant diaphragm filter, which comprises an input structure and an output structure, a resonant cavity and a self-resonant diaphragm; the self-resonant diaphragm is provided with at least a coupling hole which is communicated with the resonant cavity, the coupling hole is internally provided with at least a metal boss which is connected with other metal parts only at the bottom of the coupling hole. The upper surface of the resonant cavity and the upper surface of the coupling hole are positioned at a same flat surface, while the lower surfaces thereof are not at the same flat surface. The invention has the advantages of simple structure, small volume, good out-band rejection, wide application range, wide range of work frequency under a certain width of the filter, meanwhile, the invention can also reduce processing difficulty of the filter, is widely applied to an electronic system with varying microwave wave bands, and is especially applied to military and civil fields such as radar, missile guidance, communication and the like.

The invention discloses a tunable filter, which comprises a cavity and a tuning mechanism. At least three waveguide resonant cavities are arranged in the cavity, direct coupling is realized between adjacent waveguide resonant cavities through a direct coupling window, cross coupling is realized between non-adjacent waveguide resonant cavities through a cross coupling structure, at least one slit is arranged on the cavity wall at the same side of each waveguide resonant cavity, and the electrical length of each slit is less than the half-wavelength of the highest working frequency of the tunable filter; the tuning mechanism comprises a group of dielectric sheets and a driving mechanism, wherein the dielectric sheets are in one-to-one correspondence with the slits, and all the dielectric sheets can be simultaneously inserted into the corresponding waveguide resonant cavities at the same depth without friction through the corresponding slits under the driving of the driving mechanism. Theinvention also discloses a tunable duplexer. The tunable filter and the tunable duplexer have good out-of-band rejection characteristic, and in the whole tuning range, the relative position of the transmission zero and the bandwidth of the pass band is basically kept unchanged, and the echo of the filter is kept at a better level.

The invention discloses an octagonal ultra-wideband microstrip filter based on a defected ground structure. The ultra-wideband filter comprises an upper signal layer, a middle metal grounding layer and a bottom signal layer which are successively arranged. The upper signal layer comprises a medium substrate, a first input / output port, a second input / output port, a first octagon transmission unit and a second octagon transmission unit. The middle metal grounding layer comprises a first octagon defect unit and a second octagon defect unit. The bottom signal layer comprises the medium substrate,a third octagon transmission unit, a fourth octagon transmission unit, a uniform microstrip transmission line and an open circuit stub line. In the invention, the strong coupling effect of an octagonal defected-ground coupled transmission line is used to realize a ultra wide band, an open circuit branch knot is used to realize ultra wide out-of-band harmonic wave suppression, the design is simple,processing is convenient and cost is low.

The invention discloses a dual-mode band-pass filter with a compact structure. The dual-mode band-pass filter comprises a dielectric substrate and a filter structure positioned on the upper surface ofthe dielectric substrate on the same plane; the filter structure comprises annular resonator (1), T-shaped input feeder line (2), a T-shaped output feeder line (3), four T-shaped loading parts (4-7)and a infinitesimal disturbance sheet (8); the T-shaped loading parts (4-7) are positioned in the annular resonator (1), and each of the T-shaped loading parts comprises a parallel part and a perpendicular part perpendicularly connected with the parallel part; the parallel part of each of the T-shaped loading parts (4-7) is parallel to one edge of the annular resonator (1) separately; and the perpendicular part of each of the T-shaped loading parts (4-7) is connected to the midpoint position of one edge of the annular resonator (1) separately. By virtue of the dual-mode resonator with the T-shaped loading parts, the dual-mode characteristic can be realized, and a relatively large passband bandwidth range is achieved; and in addition, working frequency can be lowered effectively, and miniaturization of the dual-mode band-pass filter can be realized.

The Ka-band wide-stop-band filtering power divider comprises a first metal layer, a dielectric layer and a second metal layer which are stacked in sequence, an input coupling line, a first output coupling line and a second output coupling line are arranged on the side wall of the first metal layer, and an S-shaped groove is formed in the middle of the first metal layer; a plurality of conductor columns penetrate through the dielectric layer, and the conductor columns, the first metal layer and the second metal layer form a first resonant cavity, a second resonant cavity, a third resonant cavity, a fourth resonant cavity and a fifth resonant cavity. An input coupling line and an output coupling line of the filtering power divider extend into the resonant cavities, electrical coupling is realized by adopting an input and output deep feeder line structure, and the input coupling line and the output coupling line form a reasonable coupling matrix of the filter together with electrical coupling realized between the second resonant cavity and the third resonant cavity by utilizing an S-shaped groove structure; and effective suppression of coupling between high-order mode cavities is realized by using the distribution characteristics of each parasitic electromagnetic mode, and the excellent out-of-band suppression characteristic of the filtering power divider is realized.

The invention discloses an ultra wide band cavity filter, belonging to the field of microwave communication and mainly solving the problems of band width and insertion loss of a traditional filter in the prior art. The ultra wide band cavity filter comprises a cavity, resonance metal columns and two input and output structures, wherein the resonance metal columns are arranged in the cavity; and the input and output structures are arranged on the outer wall of the cavity. The ultra wide band cavity filter is characterized in that the number of the resonance metal columns is at least two; the input and output structures are respectively provided with an inner conductive body entering the cavity; and the front end of each inner conductive body extends into the inner part of one resonance metal column. The ultra wide band cavity filter has the advantages of simple structure, convenient processing and installation and high utilization value.

The invention discloses a narrowband FSS filter which comprises a waveguide, a resonant metal diaphragm and a coupling metal diaphragm. The resonant metal diaphragm and the coupling metal diaphragm are vertical to the longitudinal direction of the waveguide and are connected with four surfaces: upper surface, lower surface, left surface and right surface of the waveguide; the filter is characterized in that the resonant metal diaphragm and the coupling metal diaphragm are lengthways arranged along a filter in an interlacing manner. A coupling hole connected with an inner wall of the waveguide only in one direction of the waveguide cross section is arranged on the two metal diaphragms. The invention can meet low passband interpolation loss, high out-band rejection and the requirements on compact appearance design within a relative narrower bandwidth range. The invention has the characteristics of flexible design, simple structure and convenient process, is mainly used in the electrical system with varying microwave wave bands, and is especially applied to military and civil fields such as radar, antenna-feed system, missile guidance, communication and the like.

A wideband piezoelectric filter with a ladder-type is provided, which is composed of a plurality of first resonators connected in series, a plurality of second resonators connected in parallel, an impedance matching device disposed near the input terminal or the output terminal of the filter, and at least one special parallel ground path led out from serial nodes. The special parallel ground path at least comprises one inductor having a larger inductance value, and a resonator having the same resonant frequency as a serial branch or a capacitor, wherein the larger inductor is connected to the resonator or capacitor in series in the parallel path. The ladder filter according to the invention can have a bandwidth which is more than twice that of the conventional ladder filter, and also has excellent out-of-band rejection characteristics.

The invention discloses a three-passband power dividing filter with high frequency selectivity. The three-passband power dividing filter comprises a dielectric substrate, a metal grounding plate is arranged on the lower surface of the dielectric substrate, and an input port feeder line, a first output feeder line and a second output feeder line are arranged on the upper surface of the dielectric substrate. The input port feeder line, the first output feeder line and the second output feeder line are all located on the same side of the central axis of the dielectric substrate, and one end of the first output feeder line is connected with one end of the second output feeder line; a first resonance unit, a second resonance unit, a third resonance unit and a fourth resonance unit are sequentially coupled and connected between the input port feeder line and the first output feeder line as well as between the input port feeder line and the second output feeder line, and the four resonance units have the same structure and respectively comprise a band-pass resonator and two band-stop resonators with different sizes; and a port isolation resistor is arranged between the first output feeder line and the second output feeder line. The three-passband power dividing filter has high frequency selectivity, out-of-band harmonic suppression, power distribution characteristics and filtering characteristics.

The invention relates to a compact half-mode substrate integrated waveguide balance filter which comprises a half-mode substrate integrated waveguide, a metal blind hole array and an artificial surface plasmon structure. The metal blind hole array and the artificial surface plasmon structure are both located in a dielectric substrate of the half-mode substrate integrated waveguide, the metal blind hole array is located in a space defined by the metal via holes, and the artificial surface plasmon structure is located above the metal blind hole array. According to the invention, the metal blind hole array is introduced into the half-mode substrate integrated waveguide, and the artificial surface plasmon structure is etched above the metal blind hole array, thereby achieving the regulation and control of the slow wave characteristics of the half-mode substrate integrated waveguide. The problems that a half-mode substrate integrated waveguide balance filter is too large in size, the compactness is not high when a microwave circuit is integrated, and the out-of-band characteristic is poor are solved, and miniaturization of the balance filter structure and the good out-of-band rejection characteristic are achieved.

The invention discloses a double-end constant-resistance filtering assembly, which comprises an input terminal 1, an output terminal 2, inductors L1, L2, L3, L4 and L5, and resistors R1 and R2. The input terminal 1 is connected with the input end of the inductor L1. The output end of the inductor L1 is connected with the input end of the inductor L2, the output end of the inductor L2 is connectedwith the input end of the inductor L3, and the output end of the inductor L3 is connected with the output terminal 2; the input ends of the inductors L1 and L4 are connected with a capacitor C1 in parallel, the output ends of the inductors L1 and L4 are connected with a capacitor C2 in parallel, the input ends of the inductors L3 and L5 are connected with a capacitor C3 in parallel, and the outputends of the inductors L3 and L5 are connected with a capacitor C4 in parallel. The resistor R1 and the capacitor C5 are connected in series and then connected to the two ends of the inductor L4 in parallel, and the resistor R2 and the capacitor C6 are connected in series and then connected to the two ends of the inductor L5 in parallel. The invention provides a double-end constant-resistance filtering assembly with an ultra-wideband response working frequency band, a good out-of-band rejection characteristic and any cut-off frequency filtering design.

The invention discloses a miniaturized high performance resonator comprising a low impedance section and a high impedance section. One end of the high impedance section is connected with the low impedance section, and the other end is grounded. The low impedance section comprises a microstrip line which is closed into a loop. The invention also discloses a radio frequency filter using the miniaturized high performance resonator. The radio frequency filter comprises the resonator, a feeder line and a grounding hole. The feeder line is connected with the high impedance section of the resonator. One end, which is away from the low impedance section, of the high impedance section of the resonator is connected with the grounding hole. The loop microstrip line is arranged at the low impedance section so that the size is enabled to be less than that of the conventional resonator under the same resonant frequency, the volume of the whole communication system can be reduced, and the power consumption of the system and the manufacturing cost of the system can be reduced. Meanwhile, the loop resonator can be more flexible in design and processing because of no clad copper in the low impedance line, and thus a novel multistage resonant cascade structure can be accordingly designed.

The invention discloses a harmonic inhibition coaxial chamber filter. The harmonic inhibition coaxial chamber filter comprises two mirror image symmetric coaxial resonant chambers, wherein a couplingresonant window is arranged between the two coaxial resonant chambers, the coaxial resonant chambers are internally provided with main resonance metal columns, primary harmonic auxiliary resonance metal columns, secondary harmonic auxiliary resonance metal columns and feed units, a top portion of the coaxial resonant chambers is equipped with a fine tuning metal screw in a coaxial relationship with the main resonance metal columns, the main resonance metal columns, the primary harmonic auxiliary resonance metal columns and the secondary harmonic auxiliary resonance metal columns are respectively perpendicularly mounted at a bottom portion of the coaxial resonant chambers, the main resonance metal columns and the coaxial resonant chambers are coaxially arranged, the feed units comprise input output ports and coupling feed metal columns, the input output ports are coaxial feed wires, a top portion of the coupling feed metal columns is connected with the top portion of the coaxial resonant chambers, a bottom portion of the coupling feed metal columns is connected with inner conductors of the coaxial feed wires. The harmonic inhibition coaxial chamber filter is advantaged in that in-band filtering characteristics and out-band primary harmonic and secondary harmonic inhibition characteristics can be excellently realized.