94 results about "Passband filter" patented technology

The invention discloses a dual-passband filtering coupler based on a dielectric resonant cavity, particularly relates to the technical field of wireless communication, and solves the technical problems that in the prior art, a cavity filter and a cavity coupler often work in a cascade mode, and a matching network needs to be additionally configured between the cavity filter and the cavity coupler, so that the hardware cost is high, and the occupied system space is large. According to the technical scheme, the coupler and the dual-passband filter are integrated in one device, the circuit size can be remarkably reduced, and cascade loss between the coupler and the dual-passband filter is eliminated. The high-performance index of the microwave circuit is guaranteed, effective balance between performance and cost is achieved, and the microwave circuit completely conforms to the development direction of miniaturization, high performance and low cost of a future communication system.

The invention discloses a film bulk acoustic resonator and a filter. The film bulk acoustic resonator comprises a substrate; a cavity is formed in the top of the substrate; a first electrode located at the top of the substrate; a first piezoelectric layer on the top of the first electrode; the second electrode is positioned at the top of the first piezoelectric layer; the device further comprises at least one functional structure. The functional structure is positioned from the bottom of the first piezoelectric layer to the upper part of the second electrode; the orthographic projection of the functional structure on the substrate falls into the cavity, and the area of the orthographic projection of the functional structure on the substrate is smaller than the area of the cavity. According to the technical scheme provided by the invention, the filter formed by the resonator realizes multi-passband filter response, so that the multiplexer only comprises one filter, the miniaturization of the multiplexer is realized, and meanwhile, the heat dissipation capability can be improved.

The invention discloses a low-pass filter with reconfigurable bandwidth. The low-pass filter comprises a resonance circuit, a control circuit and a filter circuit, wherein the resonance circuit and the control circuit form a magnetic coupling resonator; the magnetic coupling resonator is used for generating a passband of the tunable zero change filter; according to the filter circuit, a passband is changed based on a tunable zero point generated by a magnetic coupling resonator, and specifically, the passband range is determined by the tunable zero point; the tunable zero point is changed by changing the control voltage of the control circuit, so that the passband width of the low-pass filter is changed, and the reconstruction of the low-pass filter is realized. The resonant circuit and the control circuit are utilized to form the magnetic coupling resonator, the passband width of the filter can be changed only by changing the control voltage introduced by the magnetic coupling resonator, and a large reconstruction range is achieved; according to the magnetic coupling resonator, the bandwidth reconstruction function can be realized only by using a small layout area.

This invention belongs to the field of microwave passive device technology and discloses a dual-passband millimeter-wave filter power divider based on a gap waveguide, comprising a metal bottom cover layer and a metal top cover layer arranged from bottom to top; wherein, the metal top cover layer includes a top cover and a top cover frequency division structure disposed on the top cover; the metal bottom cover layer includes a bottom cover and a bottom cover frequency division structure, a filtering structure, and a power divider network structure disposed on the bottom cover. The dual-passband millimeter-wave filter power divider based on a gap waveguide provided by this invention solves the technical problems of existing dual-passband filter power dividers, such as high design optimization requirements, narrow dual-frequency bands, difficulty in flexibly changing frequency bands, and high processing requirements.

The invention relates to the technical field of communication, in particular to a miniaturized wide-passband filter based on an EMSIW and a microstrip resonator. According to the miniaturized wide-passband filter, the two EMSIW cavities are adopted, the size of the filter can be effectively reduced, high-order modes TE120, TE210, TE220 and TE130 cannot be propagated in the EMSIW cavities, and therefore the filter has a wide stop band. Two microstrip resonators are embedded at a coupling window between two EMSIW cavities, and four-order quasi-elliptical filtering response is realized under the condition that no extra circuit area is occupied. Compared with other EMSIW filters, the filter has the advantages of being small in size, wide in passband, wide in stop band and good in selectivity, and has potential application value in a communication system.

Provided is a multiplexer (1) in which the insertion loss in the passband of a common-connected filter is reduced, the multiplexer (1) being provided with: a filter (10) having a first passband; and a filter (20) having a second passband closer to the higher frequency side than the first passband, the filter (10) having series arm resonators (s11-s14) and parallel arm resonators (p11-p14), the resonance frequency band width of at least one of the series arm resonators (s11-s14) being larger than that of the first passband, the series arm resonator (s11) being connected closest to the common terminal (100) among the series arm resonators (s11-s14) and the parallel arm resonators (p11-p14), and the series arm resonator (s11) being connected closest to the common terminal (100) among the series arm resonators (s11-s14) and the parallel arm resonators (p11-p14). The anti-resonance frequency (fast 11) of the series arm resonator (s11) is lower than the high-frequency end of the second passband, and is the lowest among the anti-resonance frequencies (fast 11 to fast 14) of the series arm resonators (s11 to s14).

The embodiment of the utility model relates to the technical field of communication, and particularly discloses a dual-passband filter and communication equipment, the dual-passband filter comprises a substrate and a topological structure, and the topological structure is arranged on the substrate. The topological structure comprises an input end, an output end, a first parallel line, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a first open-circuit branch knot and a second open-circuit branch knot, the input end is connected with one end of the first parallel line, the other end of the first parallel line is connected with the output end, and the output end is connected with the third microstrip line. The other end of the first parallel line, the first micro-strip line, the second micro-strip line and the first open-circuit branch knot are connected in sequence, and one end of the first parallel line, the third micro-strip line, the fourth micro-strip line and the second open-circuit branch knot are connected in sequence. By means of the mode, the topological structure is simple and compact, and miniaturization of the dual-passband filter is facilitated.

This invention relates to the field of dual-passband filter technology and discloses an ultra-narrowband high-temperature superconducting symmetrical dual-channel filter. The invention establishes a high-order coupled topology based on CT and CQ units, enabling free adjustment of the zero positions between the two sub-passbands and the introduction of a pair of transmission zeros out of the dual-passband filter, thus achieving good sideband suppression between sub-passbands and throughout the entire dual-passband filter.

Methods and apparatus for optical filtering are provided. In one example, an apparatus includes a spatial light modulator (102) having a two-dimensional array of square, rectangular, or rhombic pixels, and a controller (110) coupled to the spatial light modulator (102). The controller (110) may be configured to write image data (114) representing an image to the spatial light modulator (102) to control the spatial light modulator (102) to display the image for a frame period, and during the frame period, spatially reposition the image across a plurality of locations over the array of pixels, each single position of the plurality of positions is maintained for a respective time period, wherein the respective time period is selected according to one or more non-negative coefficients of an anti-aliasing filter transfer function (402).

The invention discloses a single-cavity dual-passband SIW filter based on capacitance loading, which comprises a first metal layer, a first dielectric layer, a bonding layer, a second dielectric layer and a second metal layer which are stacked, and a second metalized through hole group with three interference through holes which are sequentially arranged along the Y direction, the second interference through hole is formed in the central axis of the SIW resonant cavity in the Z direction, and the first interference through hole and the third interference through hole are symmetrically formed in the two sides of the second interference through hole; the second dielectric layer is provided with a first metal column and a second metal column, and the first metal column and the second metal column are arranged in a central symmetry mode with the central axis of the second interference through hole as the center. According to the SIW filter provided by the invention, independent adjustment of two passbands can be realized in a single SIW resonant cavity, the requirements of miniaturization and passband selectivity are met, and the utilization rate of a cavity mode is improved.

The invention discloses a dual-passband filter with all adjustable center frequency and bandwidth, and aims to provide a band-pass filter with low loss and wide tuning range. According to the technical scheme, each part comprises an input port, an output port, a coupled feeder line, a quarter-wavelength resonator with a variable capacitance diode loaded at the tail end, and a branch resonator with a variable capacitance diode loaded. According to the structure, a coupling line connected with a source and a load is adopted to feed a resonator in a slot coupling mode, the capacitance value of a variable capacitance diode is changed, and finally, the bandwidth and the center frequency are tunable. According to simulation verification, the center frequency of a high pass band of the all-tunable filter disclosed by the invention is continuously adjustable within 2.39-2.61 GHz, and at the moment, the center frequency of a low pass band is kept unchanged at 1.61 GHz and the bandwidth of 120 MHz; the center frequency of the low pass band is continuously adjustable within 1.45 GHz-1. 8GHz, and the center frequency of the high pass band is kept unchanged at 2.51 GHz and the bandwidth of 107MHz; the bandwidth of the high pass band is tunable in the range of 83-132MHz, the insertion loss fluctuates in the range of 1.16-1.45 dB, and at the moment, the center frequency of 1.6 GHz and the bandwidth of 122MHz of the low pass band are kept unchanged. The result shows that the microstrip filter with the tunable center frequency and bandwidth has the advantages of low loss, wide tuning range and wide application range.

The utility model discloses a topological structure which comprises a parallel line, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, an eighth microstrip line, a first open-circuit branch knot, a second open-circuit branch knot, an input end and an output end. The parallel line is composed of a first transmission line and a second transmission line which are arranged in parallel; the first end of the first transmission line is sequentially connected with the first microstrip line and the input end, and the second end of the first transmission line is sequentially connected with the second microstrip line, the third microstrip line, the fourth microstrip line and the first open-circuit branch knot. The first end of the second transmission line is sequentially connected with the fifth microstrip line, the sixth microstrip line, the seventh microstrip line and the second open circuit branch knot, and the second end of the second transmission line is sequentially connected with the eighth microstrip line and the output end. The utility model further discloses a wide dual-passband filter based on the topological structure, and the wide dual-passband filter has the advantage of miniaturization.

The utility model discloses a microstrip topological structure, which comprises a first transmission line, a second transmission line, a first microstrip line, a second microstrip line, a first open-circuit branch knot, a second open-circuit branch knot, an input end and an output end, and is characterized in that the first transmission line and the second transmission line are arranged in parallel to form a parallel line; the first end of the first transmission line is sequentially connected with the first microstrip line and the input end, the second end of the first transmission line is connected with the first open-circuit branch knot, the first end of the second transmission line is connected with the second open-circuit branch knot, and the second end of the second transmission line is sequentially connected with the second microstrip line and the output end. The utility model also discloses a dual-passband filter based on the microstrip topological structure, and the dual-passband filter has the advantage of wide passband.

The present invention provides a closed-loop RFID carrier automatic cancellation system, which includes a reader transmitter, a reader receiver, a frequency discriminator and phase detector module, a low-pass filter, a first-stage signal amplitude processing module, a second-stage signal amplitude processing module and a frequency divider. The reader transmitter is connected to the first input end of the frequency discriminator and phase detector module. The output end of the frequency discriminator and phase detector module is connected to the input end of the low-pass filter. The low-pass filter, the first-stage signal amplitude processing module, the second-stage signal amplitude processing module and the frequency divider are connected in sequence. The output end of the first-stage signal amplitude processing module is coupled to the reader receiver. The output end of the frequency divider is connected to the second input end of the frequency discriminator and phase detector module. The carrier signals generated inside the RFID reader are respectively connected to the reference ends of the first-stage signal amplitude processing module and the second-stage signal amplitude processing module. The present invention realizes the self-cancellation of the interference signals leaked from the transmitting link to the receiving link, thereby greatly improving the sensitivity of the receiver.

The present invention belongs to the field of electromagnetic fields and microwave technologies, and specifically relates to a design method for an asymmetric dual-band filter based on a frequency-variable coupling structure. The present invention applies the frequency-variable coupling structure to the design of an asymmetric dual-band filter based on two low-pass prototype functions. After converting the frequency-variable coupling matrix corresponding to the topological structure into a non-frequency-variable coupling matrix, all unknown parameters of the frequency-variable coupling matrix are optimized and solved through a constrained non-linear minimization function, thereby eliminating the original cross-coupling paths. The N-1 transmission zeros generated can be generated and independently controlled by the frequency-variable coupling structure, simplifying the topological structure of the filter and reducing the complexity of debugging. The present invention can synthesize dual-band filters with different orders, return losses, and bandwidths in different passbands and specified transmission zeros, realize an in-line topological structure, simplify the difficulty of filter design and simulation, and greatly improve the out-of-band rejection and isolation between passbands.

A system for filter enhancement, preferably including one or more analog taps and a controller, and optionally including one or more couplers. The system is preferably configured to integrate with a filter, such as a passband filter or other frequency-based filter. The system can be configured to integrate with an RF communication system, an RF front end, or any other suitable RF circuitry. A method for filter enhancement, preferably including configuring one or more analog taps, and optionally including calibrating a system for filter enhancement and / or receiving temperature information.

An optoelectronic oscillator (100) and a signal processing method, which relate to the technical field of optoelectronics. In the optoelectronic oscillator (100), an electro-optical modulator (110), an optoelectronic detector (120), a first filter (130) and a power divider (140) form an optoelectronic oscillation loop. Compared with a conventional single-passband filter, the first filter (130) in the optoelectronic oscillation loop has an additional low-frequency passband, and thus can excite a pulse train of the low-frequency passband and a pulse train of a bandpass band in the optoelectronic oscillation loop. Since the oscillation of a pulse signal can automatically narrow a pulse train to form an ultrashort pulse train, when the pulse train excited by the bandpass band has undergone pulse narrowing by means of an oscillation mechanism in the optoelectronic oscillation loop, the pulse train excited by the low-frequency passband may further undergo pulse narrowing, such that the optoelectronic oscillator (100) can generate a microwave pulse train which is shorter than that of a conventional optoelectronic oscillator, that is, an ultrashort microwave pulse train.

Filter modules having a wider passband are provided herein. In certain embodiments, the filter module comprises an input node; an output node; a filter disposed along a signal path extending from the input node to the output node; a strip line configured to generate an inductance between the filter and a ground such to increase a bandwidth of a passband of the filter module, the single strip line disposed on multiple layers, each of the multiple layers defined by a plurality of pulse-shaped) portions of the strip line disposed on a plane.

In certain embodiments, a system, computer-implemented method, and computer-readable medium for light-efficient fluorescence imaging are disclosed. The retina is flickered with broadband light, and the return light is imaged after passing through one or more filters, such as a notch filter, a low pass filter, and a high pass filter. Images may be captured with a single camera or at least two cameras, one capturing transmitted light from the filter and the other capturing return light. The images may be combined by subtraction and / or addition to obtain a combined image representing light within the passband without using a passband filter during imaging.

The invention belongs to the technical field of electromagnetic fields and microwaves, and particularly relates to a design method of an asymmetric three-passband filter based on a frequency-variable coupling structure. According to the method, a frequency-dependent coupling structure is applied to the design of the asymmetric three-passband filter based on the REMEZ-like algorithm, and after a frequency-dependent coupling matrix corresponding to a topological structure is converted into a non-frequency-dependent coupling matrix, all unknown parameters of the frequency-dependent coupling matrix are optimized and solved through a constrained nonlinear minimization function; therefore, an original cross coupling path is eliminated; and the generated N-1 transmission zeros can be generated and independently controlled by the frequency-variable coupling structure, so that the topological structure of the filter is simplified, and the debugging complexity is reduced. The three-passband filter with different orders, return losses and bandwidths can be synthesized in different passbands and specified transmission zero points, an in-line topological structure is achieved, the difficulty of filter design and simulation is lowered, and the degree of out-of-band rejection and isolation between the passbands is greatly improved.

The invention discloses a double-passband filter based on a copper-based micromachining process, which comprises a coaxial outer conductor and a coaxial inner conductor positioned in the coaxial outer conductor, and is characterized in that the coaxial inner conductor is connected with an input end feeder line and an output end feeder line; the coaxial inner conductor comprises a first quarter-wavelength transmission line, a second quarter-wavelength transmission line, a first half-wavelength transmission line and a second half-wavelength transmission line; the first quarter-wavelength transmission line and the second quarter-wavelength transmission line are simultaneously coupled with the first half-wavelength transmission line and the second half-wavelength transmission line, and the first half-wavelength transmission line and the second half-wavelength transmission line are mutually coupled. The beneficial effects of the invention are that the cable is small in transmission loss and high in signal shielding performance.

The invention relates to the technical field of filters, and discloses a flat passband filter based on an equalizer and resonator integrated architecture, comprising a dielectric substrate; the input port and the output port are arranged on the two sides of the dielectric substrate; the resonator is coupled with the input port and the output port through gaps for feeding, so that a main path with band-pass response is formed; the equalizer is loaded at the strongest electric field of the resonator through a non-resonant node to form a dynamic coupling network; and the biasing circuit is used for adjusting the coupling strength of the input port and the output port, tuning the center frequency of the resonator, and tuning the dual-resonant frequency and gain amplitude of the equalizer. According to the invention, the all-parameter flexible and adjustable cooperative control capability is realized, and the independent regulation and control of the resonator center frequency, the equalizer dual-resonant frequency and the gain amplitude are realized through the cooperative design of the variable capacitance diode and the coupling structure.

The invention discloses a circuit and a method for improving interference of local oscillator phase discrimination stray on a receiver. The circuit comprises a clock input, a local oscillator unit, a filtering and amplifying unit and a frequency conversion unit which are connected in sequence. The filtering and amplifying unit is formed by connecting a pre-amplifier, an adjustable filtering unit and a post-amplifier in series; the adjustable filtering unit comprises a passband filtering and trap wave network to realize secondary suppression. The circuit can dynamically switch paths according to spurious offset, so that phase discrimination spurious is remarkably suppressed at a specific frequency point, local oscillator signals in a wide frequency range are compatible, low insertion loss and power fluctuation are kept, and the contradiction between bandwidth and performance is effectively balanced. The receiver local oscillator is realized by adopting conventional components and switch structures, does not need a special process, is easy to be integrated into an existing receiver local oscillator circuit, and has good compatibility.

Hybrid lattice filters with acoustic baluns are disclosed. In one aspect, a hybrid lattice filter may be formed using acoustic elements. The hybrid lattice filter may operate with acoustic baluns such as coupled resonator filters (CRF) or stacked crystal filters (SCF). To achieve the desired common mode rejection, an additional rejection or low common mode intermediate impedance network may be supplied between the acoustic balun and the hybrid lattice filter. By combining the acoustic balun with the low common-mode intermediate impedance network and the hybrid lattice filter, a passband filter with a desired bandwidth may be created.

The application discloses a dual-passband filter based on a copper-based micro-processing technology, which comprises a coaxial outer conductor and a coaxial inner conductor located inside the coaxial outer conductor, an input end feeder and an output end feeder are connected to the coaxial inner conductor, the coaxial inner conductor comprises a first quarter-wavelength transmission line, a second quarter-wavelength transmission line, a first half-wavelength transmission line and a second half-wavelength transmission line, the first quarter-wavelength transmission line and the second quarter-wavelength transmission line are coupled with the first half-wavelength transmission line and the second half-wavelength transmission line at the same time, and the first half-wavelength transmission line and the second half-wavelength transmission line are coupled with each other. The application has the beneficial effects that the transmission loss is small, and the signal shielding property is high.

The present invention relates to the technical field of communication equipment components, and discloses a multi-passband filter coupling matrix design method capable of presetting out-of-band transmission zeros, comprising the following steps: converting a normalized frequency band in a low-pass prototype filter into upper and lower limit channel indicators of a multi-channel filter; designing a bandpass portion in a multi-passband filter coupling matrix; calculating a bandstop portion in a multi-passband filter coupling matrix; and generating an overall coupling matrix according to the bandpass portion and the bandstop portion in the multi-passband filter coupling matrix. The present invention can map the response of a low-pass prototype filter into an actual frequency domain, mapping it into a multi-passband filter, and is applicable to any type of resonator. Theoretically, any number of passbands and a customized bandwidth of each passband can be realized. Compared with the frequency mapping theory that has been proposed, it can realize the precise presetting of out-of-band transmission zeros, and can well improve the out-of-band suppression performance.

The embodiment of the utility model relates to the technical field of communication equipment, and particularly discloses a topological structure, a wide dual-passband filter and communication equipment, comprising a first parallel five-line and a second parallel five-line which are connected in sequence, and a first microstrip line and a sixth microstrip line which are symmetrically connected between the first parallel five-line and the second parallel five-line, the first micro-strip line is symmetrically connected with the second micro-strip line and the fourth micro-strip line, the second micro-strip line is sequentially connected with the third micro-strip line and the first short-circuit branch, the first short-circuit branch is grounded, the fourth micro-strip line is sequentially connected with the fifth micro-strip line and the second short-circuit branch, the second short-circuit branch is grounded, and the sixth micro-strip line is symmetrically connected with the seventh micro-strip line and the ninth micro-strip line. The seventh microstrip line is sequentially connected with the eighth microstrip line and a third short-circuit branch, the third short-circuit branch is grounded, the ninth microstrip line is sequentially connected with the tenth microstrip line and a fourth short-circuit branch, and the fourth short-circuit branch is grounded. Through the above mode, the embodiment of the utility model can obtain the wide dual-passband filter with small size and high selectivity based on the topological structure design.

The invention provides a photoelectric oscillator and a signal processing method. The invention relates to the technical field of photoelectricity, and in the photoelectric oscillator, an electro-optical modulator, a photoelectric detector, a first filter and a power divider form a photoelectric oscillation loop. Compared with a conventional single-passband filter, the first filter in the photoelectric oscillation loop has the advantages that a low-frequency passband is added, and a pulse sequence of the low-frequency passband and a band-pass passband can be excited in the photoelectric oscillation loop. Due to the fact that oscillation of the pulse signal can automatically narrow the pulse sequence to form the ultra-short pulse sequence, on the premise that the pulse sequence excited by the band-pass passband passes through an oscillation mechanism in the photoelectric oscillation loop to narrow the pulse, the pulse sequence excited by the low-frequency passband can further narrow the pulse, and the ultra-short pulse sequence is formed. Therefore, the photoelectric oscillator can generate a microwave pulse sequence which is shorter than that of a conventional photoelectric oscillator, namely an ultra-short microwave pulse sequence.

The invention relates to a miniaturized double-ridge dual-mode dielectric waveguide resonator and a filter comprising the resonator. The resonator comprises a frequency adjusting blind hole in the center of the upper surface, and an upper ridge and a lower ridge which are arranged on the left side and the right side of the frequency adjusting blind hole respectively and are parallel to each other. The ridge waveguide has excellent physical characteristics of low dominant mode cut-off frequency, so that the resonator can independently control a dominant mode and a high-order mode and has the characteristic of miniaturization. The miniaturized four-order rectangular double-ridge dual-mode dual-passband dielectric waveguide filter is realized by adopting the resonator, the dual-passband filter controls the frequency of a main mode by utilizing the depth of a blind hole, adjusts the frequency of a high-order mode by utilizing the depth of the double ridges, and independently controls the coupling coefficient of low frequency and high frequency by utilizing the length of a coupling window and the depth of a slotting; and dual-mode independent control is achieved while the small size is achieved.

The invention discloses an AMC loaded dual-passband waveguide filter for satellite communication, particularly relates to the technical field of wireless communication, and solves the problem that although a metal waveguide dual-passband filter is widely applied to the field of satellite communication due to the advantages of low loss, large power capacity, high Qu value and the like in the prior art, the filter cannot be applied to the field of satellite communication. However, the defect of huge volume also exists in the prior art. According to the technical scheme, resonant cavities are arranged, and the two resonant cavities are coupled through a coupling window. The input port and the output port both adopt WR-62 standard waveguides, are externally coupled with the resonant cavity through coupling windows respectively, and are the same in size; the relative size at the first high-order mode is reduced by more than 50%, and a good miniaturization design scheme is shown to meet the application requirement of satellite load miniaturization.