101 results about "Wideband bandpass filter" patented technology

The invention aims at modifying SPUDT-type surface acoustic wave filters in such a way that the wideband filter can be produced with lower insertion loss and a small form factor without substantially enlarging layout. According to the invention, this is achieved by combining the following characteristics: a) the totality of fingers (231-233; 331-333) of each transducer (2; 3) forms a tapering structure and b) the widths and the positions of the fingers are chosen in such a way that the waves reflected on the fingers (231-233; 331-333) together with the waves regenerated by the corresponding source and load resistance (8; 9) result in an lengthening of the impulse response of the filter, which reduces form factor and / or bandwidth. The invention can be used in surface acoustic wave-based components such as wideband bandpass filters and delay lines.

A tunable wideband bandpass filter that can digitally vary the center frequency and bandwidth of a signal to be filtered, and includes a plurality of switched-capacitor banks for varying capacitance and converting the center frequency and bandwidth into a digital signal, and a plurality of inductors provided for inductance to generate the center frequency, the plurality of switched-capacitor banks that may be integrated into a signal chip.

A filter unit comprises a wideband bandpass filter; at least one band-elimination filter having a stop band within the passband of the bandpass filter, so that the passband is divided into a plurality of pass bands by the stop band; and the wideband bandpass filter and the band-elimination filter being disposed in a single dielectric member. Since the passband of a wideband bandpass filter is divided into a plurality of pass bands by stop bands of one or more band-elimination filters, signals having frequencies corresponding to these divided pass bands are able to pass through the filter unit simultaneously.

The invention discloses a broadband bandpass filter with frequency and bandwidth reconfigurable. The broadband bandpass filter comprises an upper-layer microstrip line structure, an active circuit, a middle-layer dielectric substrate, a lower-layer grounding metal paster and a metal through hole, wherein the metal through hole sequentially penetrates through the microstrip line structure, the dielectric substrate and the grounding metal paster so that the microstrip line structure and the grounding metal paster can be connected through the dielectric substrate, the microstrip line structure comprises a first port feeder line, a second port feeder line, a first resonator and a second resonator, the first port feeder line and the second port feeder line are symmetrical left and right, the first resonator is arranged above the first port feeder line and the second port feeder line, the second resonator is arranged below the first port feeder line and the second port feeder line, and the whole microstrip line structure is of a cross-shaped structure. The frequency and the bandwidth of the broadband bandpass filter can be independently reconfigurable, the two sides of a passband are each provided with a transmission zero point, the rectangularity and the selectivity of the filter are improved, and overall performance is good.

The invention relates to a small ultra-wideband bandpass filter with a notch performance. The whole filter is made of microstrip lines. A microstrip structure comprises three layers which are an upper-layer microstrip structure, a middle-layer dielectric substrate and lower-layer grounded metal respectively. The upper-layer microstrip structure comprises an input feeder line, an output feeder line, a parallel coupled microstrip line, a metal through hole, an open circuit branch line and two short circuit branch lines; the two short circuit branch lines are connected to two ends of the parallel coupled microstrip line respectively and used for generating transmission zeros at two ends of a filter pass band, so that the selectivity of the ultra-wideband filter is enhanced; and the position of each transmission zero can be changed by adjusting the length of each short circuit branch line. The frequency band and bandwidth of a notch can be flexibly changed by adjusting parameters such as the line width, the length and the like of the open circuit branch line. According to the filter, the pass band range can be ensured to cover the whole ultra-wide frequency band and interfering frequency components in the frequency band can be pointedly inhibited; and the filter has the characteristics of simple and compact structure and excellent performance.

The invention belongs to the field of passive microwave solid-state circuits, in particular to an ultra-wideband band-pass filter structure with a wide stop band and high selectivity. The filter structure comprises a dielectric substrate 2, a metal foil layer 1 attached to the upper surface of the dielectric substrate, and a metal grounding layer 3 for covering the lower surface of the dielectricsubstrate; the front surface of the metal foil layer 1 is a combined shape formed by a cone and a rectangle, and the combined shape is composed of micro-strip transmission lines 5, open-circuit stub lines 6, substrate integrated waveguide upper surfaces 7, compact microstrip resonant cells 8, conical microstrip gradual change lines 9 and complementary opening resonance rings 10; and the metal foillayer 1 is connected with the metal grounding layer 3 through two rows of metallized through holes 4 which penetrate through the whole dielectric substrate. According to the filter structure, the transmission characteristics of the substrate integrated waveguide and the CMRC are ingeniously combined, and the functions of the ultra-wideband band-pass filter with the wide stop band and high selectivity can be finally realized by introducing the complementary opening resonance rings and the open-circuit stub lines capable of generating transmission zero points.

The ultra-wide-band filter serves as a key unit in an ultra-wide-band communication system and determines the overall performance of the system. The invention relates a microstrip ultra-wide-band band-pass filter based on a novel multi-branch multi-mode resonator. The filter is characterized in that two ends of an intermediate short-circuit transmission line node 33 are connected with two ends of a transmission line node 32 to form a closed loop, wherein the short circuit of the intermediate short-circuit transmission line node 33 is realized by a metalized through hole 34. An open-circuit transmission line node 31, an open-circuit transmission line node 35, an open-circuit transmission line node 36, an open-circuit transmission line node 37, an open-circuit transmission line node 38, and an open-circuit transmission line node 39 are respectively connected to the transmission line node 32. In addition, the filter performances are improved by connecting matching branches including a short-circuit transmission line node 12 and an open-circuit transmission line node 14 at an input port and connecting matching branches containing a short-circuit transmission line node 22 and an open-circuit transmission line node 24 at an output port, wherein the short circuit of the short-circuit transmission line node 12 is realized by a metalized through hole 13 and the short circuit of the short-circuit transmission line node 22 is realized by a metalized through hole 23. Researches show that the provided microstrip ultra-wide-band band-pass filter has advantages of high performance and miniaturization and the like.

An ultra-wideband filter is a key device in an ultra-wideband communication system, and the performance of the filter determines the integral performance of the system. The invention relates to a micro-strip ultra-wideband band pass filter, which is based on a novel multi-mode resonator (an open-circuit transmission line section 31 and an open-circuit transmission line section 32 are connected to one end of a parallel-coupled line section 33, and meanwhile the other end of the parallel-coupled line section 33 is connected with an open-circuit transmission line section 34 and an open-circuit transmission line section 35). In addition, matching branch nodes (a short-circuit transmission line section 12 (short circuiting is realized through a metallized through hole 13) and an open-circuit transmission line section 14) are connected to an input port, and matching branch nodes (a short-circuit transmission line section 22 (short circuiting is realized through a metallized through hole 23) and an open-circuit transmission line section 24) are connected to an output port to further improve the performance of the ultra-wideband band pass filter. Research shows that the ultra-wideband band pass filter has the advantages of compact size, excellent performance and the like.

The invention relates to a micro-strip ultra wideband band-pass filter having wave trapping characteristic. The entire filter is manufactured on a micro-strip line, and the micro-strip line comprises three layers, namely, a metal overlying layer, a medium substrate and a metal underlying layer. The metal overlying layer is etched with metal patterns respectively, and comprises an input feeder line 1, an output feeder line 2, a parallel three-line coupled structure 3, a metallization through hole 5, an open-circuit branch 6 and an open-circuit branch 7, wherein the input feeder line 1 and the output feeder line 2 are connected with the parallel three-line coupled structure 3 respectively; the parallel three-line coupled structure 3 is connected with the open-circuit branch 6 and the open-circuit branch 7 through the metallization through hole 5. A rectangular defected ground structure 4 positioned below the parallel three-line coupled structure 3 is etched on the metal underlying layer, and is used for enhancing the coupling strength of the parallel three-line coupled structure 3. The bandwidth of the filter can cover an ultra-wideband frequency range, the wave-trapping frequency position can be adjusted independently, and very high flexibility is realized. Moreover, the filter has the advantages of compact size, excellent performance and the like.

The invention discloses an asymmetric SIR loaded wide stop band rejection broadband band-pass filter. The broadband band-pass filter has high / far out-of-band rejection performance. The filter is realized through the following technical schemes that: a multimode filter input port Pin is connected with a first interdigital feed structure through a 50-ohm microstrip line; a stepped impedance resonator SIR is loaded at the lower left side of a multimode resonator; the multimode resonator is composed of an inverted pi resonator, a T-shaped stub loaded at the upper side of the center of the invertedpi resonator and an open-circuit stub loaded at the lower side of the center of the inverted pi resonator; a second interdigital feed structure is connected with a Pout port through a sixth microstrip line; the first interdigital feed junction and the second interdigital feed structure are in mirror symmetry relative to a T-T*axis; signals inputted from the input port Pin couple energy to the multimode resonator through the first interdigital feed structure; and the energy is coupled to the output port Pout through the second interdigital feed structure.

A wideband bandpass filter includes an RF input terminal, an RF output terminal, a plurality of electrically tunable coupling capacitors coupled in series between the RF input and output terminals, and a plurality of resonating circuits each including an electrically tunable resonator capacitor coupled to one of the coupling capacitors. At least one resistance is coupled in series between at least one of the coupling capacitors for providing enhanced out of band rejection of the filter.

The invention relates to a ground magnetic resonance signal detecting device with an automatic gain adjusting function, wherein a frontend amplifying circuit is connected with a narrowband filter circuit through a wideband bandpass filter circuit. The frontend amplifying circuit is connected with an FPGA module through a presampling ADC module. The narrowband filter circuit is connected with a main sampling ADC module through a programmable amplifier circuit. The FPGA module is connected with the programmable amplifier circuit, the main sampling ADC module, an SCI interface and a network interface. A computer is connected with the SCI interface and the network interface. According to the ground magnetic resonance signal detecting device, magnification magnitude of the programmable amplifier circuit is adjusted in real time through a pre-sampling AD, thereby effectively inhibiting amplifier saturation. Furthermore the input value of the main sampling AC reaches a full measuring range as possible, thereby improving signal sampling precision. Because a main sampling AD is triggered and controlled by external interruption, accurate synchronization between the pre-sampling AC and main sampling AD is realized, and good matching between each sampling value and magnification magnitude at this time is ensured.

An ultra-wide band filter is a key device in an ultra-wide band communication system and determines the overall performance of the system. The invention relates to a microstrip ultra-wide band pass filter, which is based on a novel T-shaped sub-loaded half-wavelength resonator. The microstrip ultra-wide band pass filter is characterized in that an open circuit transmission line node 31 and an open circuit transmission line node 39 form a half-wavelength resonator, and a terminal open circuit T-shaped structure 32 is loaded in the middle of the half-wavelength resonator; the terminal open circuit T-shaped structure 32 is coupled to a transmission line node 33 the two ends of which are short circuits, and the short circuits are realized by a metalized through hole 34 and a metalized through hole 35; a terminal short circuit T-shaped structure 36 is loaded in the middle of the half-wavelength resonator, and short circuits are realized by a metalized through hole 37 and a metalized through hole 38. Moreover, an input end and an output end of the filter are each connected to a quarter-wave transmission line node to improve the frequency selectivity of the filter. The research shows that the ultra-wide band pass filter has the excellent frequency characteristic, etc.

The invention relates to a filter, in particular to a broad band band-pass filter with a multilayer structure. According to the design, a lumped parameter element model of the band-pass filter is achieved by adopting a multilayer micro-strip structure, inductors are designed by using spiral broken lines, capacitors are designed by adopting a flat plate structure, and equivalent resonance circuits are formed by combining the spiral inductors and the flat plate capacitors. The broad band band-pass filter with the multilayer structure is structurally composed of three metal conduction band layers and two transmitting medium layers, wherein the series connection of the two inductors L1 and one coupling capacitor C0 is achieved on the first metal conduction band layer, the two series resonance circuits are connected in parallel on the second metal conduction band layer, the ground connection of three metal via holes is achieved on the third metal conduction band layer, and ground capacitance coupling is removed by digging cracks. Through the combination of the modern technology, the broad band band-pass filter with the multilayer structure is capable of meeting the requirements for miniaturization and broad bands, and has certain simple practicality.

The invention provides a miniaturized composite right / left-handed structure broadband filter. The miniaturized composite right / left-handed broadband filter comprises a back copper coating layer, a dielectric substrate and a front circuit, wherein the back copper coating layer, the dielectric substrate and the front circuit are arranged in sequence from bottom to top, the front circuit comprises five composite right / left-handed transmission line resonators, each composite right / left-handed transmission line resonator comprises an interdigital part, a straight microstrip line, a through hole welding disc and a metallized through hole, the five composite right / left-handed transmission line resonators are vertically arranged in parallel, the interdigital parts and the straight microstrip lines of every two adjacent resonators are alternately arranged up and down, and two microstrip lines are respectively connected to the straight microstrip lines of the resonators on the left and right ends so as to be used as input and output ports. The miniaturized composite right / left-handed structure broadband filter contains the novel composite right / left-handed transmission line resonators, and compared with a traditional resonator, the novel composite right / left-handed transmission line resonators are compact and small; the interdigital parts and the straight microstrip lines of every two adjacent resonators are alternately arranged up and down, and strong coupling is generated between resonant elements, so that a broadband bandpass filter is favorably formed, and the size is greatly reduced in the condition that broadband bandpass characteristics are realized.

The invention discloses a multifunctional radar detection waveform generating method. The multifunctional radar detection waveform generating method comprises the following steps that a narrow-band linear frequency modulation waveform is generated; window adding processing is performed to obtain the narrow-band linear frequency modulation waveform undergoing the window adding processing; gaussian white noise is generated; wide-band band-pass filter processing is conducted on the generated gaussian white noise to generate colored gaussian noise; the colored gaussian noise modulates sine wave frequency to generate a wide-band noise frequency modulation waveform is generated; the filter wide-band noise frequency modulation waveform is obtained through band elimination filter processing; the narrow-band linear frequency modulation waveform undergoing the window adding processing and the wide-band noise frequency modulation waveform are synthesized in time domain to generate the multifunctional radar detection waveform. The interference performance of the radar detection waveform can be effectively improved through random generation of center frequency, the detection performance of the multifunctional radar detection waveform is improved through the window adding processing, the multifunctional characteristics of the radar detection waveform are effectively improved through the band elimination filter processing conducted on the generated wide-band noise frequency modulation waveform.

The invention discloses a broadband band-pass filter based on a seven-mode resonator. The broadband band-pass filter comprises a first input / output port, a second input / output port, an intermediate layer medium substrate, an upper microstrip structure arranged on the upper surface of the intermediate layer medium substrate, and a bottom metal floor arranged at the bottom surface of the intermediate layer medium substrate. The broadband band-pass filter is characterized in that the upper microstrip structure comprises a first feeding network, a branch-loaded annular seven-mode resonator, and a second feeding network. According to the broadband band-pass filter, the branch-loaded annular multi-mode resonator is employed, seven resonance modes can be provided in the broadband passband frequency range, and the transmission and reflection characteristics are better in the passband; and the annular double-path structure can respectively generate a transmission zero at the upper side and the lower side of the passband so that the passband selectivity of the broadband filter is greatly improved, the integration is easy, and the cost is low.

The invention discloses an ultra wide band bandpass filter based on ground defective grounding structure. The bandpass filter comprises a circuit board with micro-strip boards coated on two sides, on the front surface of the bandpass filter and a ground plate on the back surface of the bandpass filter, wherein the circuit board comprises a first coupling micro-strip board and a second coupling micro-strip board which are parallel to each other, the coupling micro-strip board is connected with an input terminal through an input terminal transmission line, the second coupling micro-strip board is connected with an output terminal through an output terminal transmission line; the ground plate comprises a first, second and third inverse S-shaped defective grounding structures, wherein the first inverse S-shaped defective grounding structure is arranged at the center of the space under the first coupling micro-strip board and the second coupling micro-strip board which are parallel to each other on the circuit board, and the second and third inverse S-shaped defective grounding structures are arranged symmetrically on the two sides of the first inverse S-shaped defective grounding structure and separately arranged at the centers of the spaces under the output terminal transmission line and the input terminal transmission line. The ultra wide band bandpass filter based on ground defective grounding structure of the invention is a DGS ultra wide band bandpass filter of which wideband can cover any ultra wide band frequency section (3.1-10.6GHz).

The aim of the invention is to modify prior art converters for surface acoustic waves in such a way that, despite an essentially homogeneous amplitude profile, other weighting factors can also be realized as 0 or ±1. The invention considers converters of the prior art that consist of prong groups which are comprised of at least two prongs, are arranged on a piezoelectric substrate, and which are assembled to form collector electrodes. According to the invention at least some of the prong groups are constructed in such a way that they differ from the remaining prong groups with regard to the wave amplitude excited thereby. In order to fulfil the aim of the invention, a combination of the following features is provided: a) the prongs form, in their entirety, a structure which tapers in a prong direction, and; b) at least some of the prong groups (21; 23; 31; 33), designated as structured prong groups, are subdivided, in a prong direction, into a number of subconverters (231; 232; 331; 332) and these subconverters are electrically connected in series. The invention can be used in components which function on the basis of surface acoustic waves, for example, in broadband band-pass filters and in delay lines.

The invention discloses a novel adjustable bandwidth type ultra-wide-band filter. The filter comprises two pairs of coupling lines, three open microstrip transmission lines, five grounded microstrip lines, five power supply microstrip lines and five short microstrip lines. By loading varactors between the parallel coupled lines and the tail portions of the transmission lines, resonant mode and bandwidth are controlled, so that the adjustable bandwidth type ultra-wide-band filter is formed. By loading varactor values between the parallel coupling lines, coupling intensity can be adjusted, so that insertion loss can be effectively controlled. By loading varactors at terminals by means of the transmission characteristics of half-wavelength open transmission lines, the position of a generated transmission zero point can be adjusted. By means of the coupling lines with the varactors arranged in between and the half-wavelength open transmission lines with the varactors arranged on the terminals, good transmission characteristics can be realized, two side bands of a passband can be independently adjusted, and the restrain amplitude of an upper stop band within a broadband range can reach 40 dB; the structure is simple, electric property is high, and circuit integration and system packaging can be achieved easily.

The invention discloses a wideband band-pass filter power amplifier based on frequency selective coupling, includes a gate DC bias circuit, an input impedance matching circuit, a power amplifier transistor, and an output impedance matching circuit. The output impedance matching circuit comprises a tuned microstrip line connected between the power amplifier transistor and the bandpass filter, and abandpass filter composed of a first resonator and a second resonator coupled in parallel. The tuned microstrip line is connected between the power amplifier transistor and the bandpass filter. The invention utilizes a broadband bandpass filter based on frequency selective coupling, and considers the extended continuous type theory and the filter synthesis theory, thereby effectively improving theworking efficiency and the bandwidth of the filter power amplifier, and simultaneously effectively reducing the complexity and the area of the impedance matching circuit in the traditional inverse F-type power amplifier.

The invention provides a broadband band-pass filter capable of loading three-branched coupling microstrip lines. The broadband band-pass filter comprises two first microstrip lines, two second microstrip lines, two third microstrip lines, two fourth microstrip lines, two fifth microstrip lines, two sixth microstrip lines, two seventh microstrip lines and two signal transmission ends which are arranged on the surface of a dielectric plate, wherein the broadband band-pass filter is bilaterally symmetrical about a first central axis; the broadband band-pass filter is longitudinally symmetrical about a second central axis; the first central axis is the connecting line of middle points of an upper transverse frame and a lower transverse frame of the broadband band-pass filter; and the second central axis is the connecting line of middle points of an upper longitudinal frame and a lower longitudinal frame of the broadband band-pass filter. According to the broadband band-pass filter provided by the invention, high selectivity for band-pass signals can be realized, little noise is introduced, and interference for radio-frequency front end is avoided.

The invention discloses a broadband band-pass filter based on a spiral defected ground. The broadband band-pass filter based on the spiral defected ground is obtained through a micro-strips and comprises a micro-strip substrate, a bottom ground and a top micro-strip circuit, wherein line troughs which are in odd symmetry about the center and are mutually nested are formed in the bottom ground, the line troughs are respectively of a spiral structure, two spiral trough lines which are in odd symmetry about the center and are nested with each other in a coupling mode are formed in each wiring duct, and a trough line resonator of a spiral structure is formed by every two corresponding spiral trough lines; the top micro-strip circuit comprises an input tap, an output tap, a first stepped impedance feeder and a second stepped impedance feeder, the first stepped impedance feeder and the second stepped impedance feeder correspond to the peripheral trough lines of the mutually nested spiral trough lines in the bottom ground, and the first stepped impedance feeder and the second stepped impedance feeder in the top micro-strip circuit are coupled with the trough line resonators of the bottom ground so that a resonant model can be stimulated. The broadband band-pass filter based on the spiral defected ground is simple and compact in structure and high in band-passing property and band-stopping property, and microwave circuit integration can be achieved conveniently.

An ultra wide band band-pass filter is a key device in an ultra wide band communication system, whose performance plays a key role in the whole performance of the system. The invention relates to an ultra wide band band-pass filter based on a novel multimode resonator which is shaped like a Chinese character wang. In the resonator, an open-circuit transmission line knot 31 and an open-circuit transmission line knot 36 are connected to parallel coupling line knots 32. One end of each of theparallel coupling line knots 32 is connected to an open-circuit transmission line knot 33. The other end of each of the parallel coupling line knots 32 is connected to a parallel coupling line knot 34 and a parallel coupling line 35. In addition, matching branches comprising a short-circuit transmission line knot 12 which is short circuited by a metal through hole 13, and an open-circuit transmission line knot 14, are accessed to an input port and matching branches comprising a short-circuit transmission line knot 22 which is short circuited by a metal through hole 23, and an open-circuit transmission line knot 24, are accessed to an output port, so performance of the ultra wide band band-pass filter is further improved. The study shows that the ultra wide band band-pass filter is characterized by high performance and small size.

The invention discloses a miniaturized broadband band-pass filter based on spiral resonators. The miniaturized broadband band-pass filter is realized in a microstrip form and comprises a microstrip substrate, a bottom layer ground and a top layer microstrip circuit, wherein the microstrip substrate is formed on the bottom layer ground, the top layer microstrip circuit is formed on the microstrip substrate, and the top layer microstrip circuit comprises an input tap, an output tap and a resonator array connected between the input tap and the output tap. The coupling strength between the resonators is greatly improved by adopting nest coupling, the tap type feeding mode is combined, and the broadband band-pass filter is easy to realize. The resonators are simple and compact in structure, convenient to machine and manufacture and suitable for microwave integrated circuits.

The invention discloses a broadband bandpass filter based on an interdigitated coupling multi-mode resonator (MMR), which comprises two mixed interdigitated coupling high impedance structures, one cross low impedance structure and two microstrip lines. The filter consists of a low-impedance resonator formed by the cross structure in the center, two four-wire interdigitated coupling structures located on both sides of the cross structure, a dielectric substrate and the underlying metal layer, and two microstrip lines connected as a whole to form a complete the resonant structure. This filter has a simple structure, is easy to process, has good electrical performance, has a large working bandwidth, and has good out-of-band characteristics. Compared with other types of broadband bandpass filters, it has the advantages of being more compact and easy to implement.