57 results about "Chebyshev filter" patented technology

Described herein is a probe card assembly providing signal paths for conveying high frequency signals between bond pads of an integrated circuit (IC) and an IC tester. The frequency response of the probe card assembly is optimized by appropriately distributing, adjusting and impedance matching resistive, capacitive and inductive impedance values along the signal paths so that the interconnect system behaves as an appropriately tuned Butterworth or Chebyshev filter.

The invention discloses a direct and integrated design method of band-pass filters. In order to overcome the defect that the coupling matrix derived from the traditional integrated design method of the generalized Chebyshev single-pass-band or multi-pass-band band-pass filters is only narrow-band approximation and can not be used for integrated band-pass filters, the method is available for integrating the generalized Chebyshev single-pass-band or multi-pass-band band-pass filters in a band-pass domain directly, and improving the group delay characteristic in the pass band of the filter by introducing a plurality of transmission zeros. The direct and integrated design method can be used for extracting a network matrix of the generalized Chebyshev band-pass filters of the transmission zeros which have any bandwidth and are positioned at any frequency; and the derived network matrix has practical physical significance, while the network matrix derived from the traditional scheme can be taken as a low-pass narrow-band approximation result of the network matrix derived by using the method disclosed by the invention. The whole method disclosed by the invention has the advantages of simpleness, fastness and accuracy.

A method for measuring bridge structure dynamic displacement and vibration frequency is provided. The method includes the following steps of: (1) establishing a bridge structure vibration field monitoring system so as to synchronously acquire vibration displacement and global navigation satellite system (GNSS) time; (2) performing coordinate system projection conversion which comprises the steps of calculating projection parameters between a local coordinate system and a bridge independent coordinate system and transforming measured structure vibration coordinate projection into the bridge independent coordinate system; (3) filtering bridge structure vibration displacement gross errors; (4) re-sampling vibration displacement through using a linear interpolation method; (5) separating quasi-static parts from dynamic parts in displacement by using a Chebyshev filter; and (6) analyzing vibration signal frequency spectrums through using a fast Fourier method. The method of the invention has the advantages of non-contact property, high precision, high reliability, high automation and the like.

An LTCC bandpass filter with harmonic suppression belongs to the technical field of electronics and relates to bandpass filters with harmonic suppression. The bandpass filter with harmonic suppression is a two-stage bandpass filter with one transmission zero, adopts the prototype of a deformed Chebyshev filter with controllable transmission zeros, realizes elements with equivalent lumped parameters through an LTCC multilayer structure and can greatly reduce the volume of the bandpass filter under the condition of realizing the same technical index. Meanwhile, the bandpass filter can effectively enhance the out-of-band harmonic suppression effect under the condition of using bipolar resonance, thus better giving consideration to the requirements of insertion loss of the bandpass filter on pass bands and stop bands. Besides, the bandpass filter has the advantages that the traditional bandpass filters do not have, including low cost, benefit for batch production, good high-frequency performance and temperature performance and the like. The bandpass filter can be widely applied to the radio frequency wireless communication systems.

The invention relates to a generalized Chebyshev filter integrated design method based on conformal transformation. The method comprises the steps of Step 1, constructing a characteristic function in a z region; Step 2, deriving polynomials from the characteristic function according to indexes; Step 3, converting polynomials and scattering parameters formed by the polynomials into admittance parameters; Step 4, conducting partial fraction expansion on the admittance parameters, and contrasting the admittance parameters with corresponding admittance parameters in a transverse equivalent circuit, so that corresponding parameters such as coupling coefficients and resonant frequencies can be determined, and a network matrix which is represented in a global resonance mode can be obtained; and Step 5, converting the network matrix which is represented in the global resonance mode into a desired sparse topological structure through multiply transformation, rotation transformation and the like. Compared with the prior art, the method has the advantages that generalized Chebyshev band-pass filters of any bandwidth can be synthesized, transmission zero can be located at any limited frequency or an infinity position, and the method is simple and easy to implement.

Described herein is a probe card assembly providing signal paths for conveying high frequency signals between bond pads of an integrated circuit (IC) and an IC tester. The frequency response of the probe card assembly is optimized by appropriately distributing, adjusting and impedance matching resistive, capacitive and inductive impedance values along the signal paths so that the interconnect system behaves as an appropriately tuned Butterworth or Chebyshev filter.

The invention relates to a direct integrated design method for a random-bandwidth multi-pass-band generalized Chebyshev filter. The method comprises the following steps of: 1, according to indexes of an analog filter to be integrated, performing independent integrated design on each pass band according to single-pass-band filters, and deriving a characteristic function and a polynomial, which correspond to each single-pass-band filter; 2, substituting the characteristic functions and the polynomials into a superposition relational expression, deriving the corresponding polynomials and determining final characteristic functions of the analog filter to be integrated; 3, converting a scattering matrix which is formed by the polynomials into a theoretic admittance matrix; and 4, performing partial fraction expansion on the theoretic admittance matrix which is obtained in the step 3, and thus obtaining a transverse network matrix of the analog filter to be integrated, which is represented in a global resonant mode. The direct integrated design method for the random-bandwidth multi-pass-band generalized Chebyshev filter has the advantages that network matrixes of various topological equivalent circuits for realizing the frequency response of the analog filter to be integrated can be directly derived, and final physical implementation is facilitated.

The invention discloses a cross-coupled terahertz rectangular cavity filter with transmission zeros. The filter structurally comprises transition waveguides, rectangular resonant cavities and coupling windows. By taking a four-order Chebyshev filter as a prototype, the resonant cavities are arrayed in vertical mirror symmetry according to a CQ topological structure; main coupling of the filter is realized by means of H-surface deflection and making of rectangular windows, and cross coupling of the filter is realized by the aid of the coupling windows among the resonant cavities. The cross-coupled terahertz rectangular cavity filter has the advantages of low return loss in a filter transmission band, low insertion loss and high suppression degree due to two transmission zeros at two ends of the transmission band. By the cross-coupled terahertz rectangular cavity filter with the transmission zeros, cross coupling in the terahertz frequency band is realized for the first time, and the filter is excellent in performance, simple in structure and especially applicable to a SU-8 layered thick-film process.

The invention discloses a wide-stopband waveguide band-pass filter with loading inductance diaphragms and capacitance diaphragms loaded in a staggered mode, and belongs to the technical field of microwaves. The waveguide band-pass filter comprises a rectangular waveguide, wherein N pairs of inductive diaphragms are arranged in the rectangular waveguide in the axial direction, and a pair of capacitive diaphragms is arranged between every two adjacent pairs of inductive diaphragms. Based on the design theory of the Chebyshev filter and the capacitance loading shortening theory of the resonant cavity of the transmission line, the wide-stopband waveguide band-pass filter adopts the out-of-band transmission pole control technology of the staggering resonator to finally achieve the miniaturization and wide-stopband suppression waveguide band-pass filter.

The invention discloses a Wilkinson power divider with isolation frequency point aligned Chebyshev filtering characteristics, which comprises an input end and two output ends, and also comprises two transmission branches connected in parallel between the input end and the two output ends; Each transmission branch is formed by connecting n sections of first transmission lines and one section of second transmission line in series; Wherein the second transmission line is selectively connected to the starting end or the tail end of the transmission shunt; The plurality of resistors are respectively connected between every two corresponding sections of transmission lines on the two transmission branches; The two groups of short-circuit wires are symmetrically connected to the two transmission branches; Each group of short-circuit lines comprises m short-circuit lines, and m is greater than or equal to 2 and less than or equal to n; When m is an even number, the short-circuit lines are connected to symmetrical positions on the two sides of the center of the n sections of first transmission lines; And when m is an odd number, the short circuit lines are connected to the central positionsof the n sections of first transmission lines and the symmetrical positions on the two sides of the central positions. The invention also provides a preparation method of the power divider.

The invention discloses an impedance transformer with Chebyshev filter property of multi-order transmission lines and short-circuited line. The impedance transformer comprises an input end unit and anoutput end unit, impedance transformation units serially connected between the input end unit and the output end unit in order through the multi-order transmission lines, and short-circuited lines, wherein the amount of the short-circuited line is not more than that of the multi-order transmission line; when the multi-order transmission lines are in the odd-order, the number of the short-circuitlines is odd segments and the short-circuited lines are symmetrically distributed at two sides of the center of the multi-order transmission lines; when the multi-order transmission lines are in even-order and the number of the short-circuited line is even segments, the short-circuited lines are symmetrically distributed at two sides of the center of the multi-order transmission lines; when the multi-order transmissions lines are in even-order and the number of the short-circuited line is odd segments, a segment of short-circuited line is arranged at the center of the multi-order transmissionlines, and the rest short-circuited lines are symmetrically distributed at two sides of the center of the multi-order transmission lines. The invention further provides a preparation method of the impedance transformer with Chebyshev filter property of the multi-order transmission lines and short-circuited lines.

The invention discloses a leakage current detecting fast protection circuit in the field of power electronics. The leakage current detecting fast protection circuit comprises a current transformer installed on a loop to be tested. A secondary side output winding of the current transformer is connected with both ends of a self-excited oscillator. An output end of the self-excited oscillator is connected with an input end of the fast protection circuit. An input end of the self-excited oscillator is connected with a non-ground end of a sampling resistor, and at the same time, the non-ground endof the sampling resistor is connected with an input end of a Chebyshev filter. An output end of the Chebyshev filter is connected with an input end of a sampling conditioning unit. The sampling conditioning unit includes a signal voltage dividing resistor and an operational amplifier. The output end of the Chebyshev filter is connected with one end of the signal voltage dividing resistor, and theother end of the signal voltage dividing resistor is connected directly with an output end of the fast protection circuit and an in-phase input end of the operational amplifier in the sampling conditioning unit. An output end of the sampling conditioning unit is connected with a controller. The leakage current detecting fast protection circuit of the invention is safer and more rapid when detecting a large leakage current, and can be used in photovoltaic grid-connected power generation.

The invention provides a wind turbine generator wide-frequency-band additional damping control method which comprises the steps of carrying out oscillation mode decomposition through Chebyshev filtersof different frequency bands and according to the rotating speed difference of a draught fan, and obtaining the oscillation components of all the frequency bands; respectively carrying out adaptive variational mode decomposition on the oscillation component of each frequency band to extract an oscillation mode signal of each frequency band; respectively carrying out a Prony algorithm on the oscillation modal signals of each frequency band to extract the oscillation modal parameters of each frequency band; according to the oscillation modal parameters of each frequency band, based on a lead-lag correction model, performing optimization calculation by using a quantum particle swarm algorithm to obtain the optimization control parameters of damping control of each frequency band; integratingthe output of the additional damping controllers of multiple frequency bands, and superposing the final control quantity to a current inner loop controlled by a wind turbine generator, thereby inhibiting different oscillation modes. according to the method, the damping controllers are designed respectively, so that the independence of different types of damping functions is ensured, and the crossinfluence of different types of damping inhibition is reduced.

The invention discloses a Wilkinson power divider with a Chebyshev filter characteristic based on multi-segment coupling line cascading. The Wilkinson power divider comprises a source terminal impedance unit and two sets of load terminal impedance units, and is characterized in that the source terminal impedance unit and the two sets of load terminal impedance units are connected by two sets of power distribution units which are connected in series through a plurality of even-number-segment coupling lines and then connected in parallel; one ends of the power distribution units are separately and simultaneously connected to the source terminal impedance unit, and the other ends of the power distribution units are separately and simultaneously connected to the load terminal impedance units through at least one of equal number of transmission lines; and both ends of coupling lines connected to the transmission lines are connected by a resistor. The invention further discloses an optimization establishing method of the Wilkinson power divider with the Chebyshev filter characteristic based on multi-segment coupling line cascading.

A reconfigurable system is used for amplifying, filtering, and sampling analog signals. Unlike conventional analog filters and amplifiers based on linear time-invariant systems and classical filter responses such as Butterworth or Chebyshev filters, the system described here uses parallel branches comprising time-varying circuits. An input voltage or current is communicated to a number of parallel branches and each branch processes a segment of the input signal using time-varying circuits such as analog multipliers and / or super-regenerative amplifiers. The time-window of the input signal processed by each branch is equal in length, but offset in time from all other branches. The output of each branch is a series of filtered and amplified samples of the input signal. The output samples of all branches are then time-interleaved in the analog domain, or digitized using separate analog-to-digital converters and then time-interleaved digitally. By using time-varying circuits, sharper filters and greater amplification is achieved while consuming less integrated-circuit area and power. The time-varying circuits in each branch are controlled by synthesized signals that determine the filter response and gain of the overall system. As a result, better flexibility and reconfigurability are achieved compared with classical filters and amplifiers.

The invention provides a communication method and system based on a filter. The method comprises the steps of carrying out the low-frequency signal filtering and signal conversion processing of a baseband signal through an improved transmitting device, and transmitting the converted baseband signal to a channel; designing a receiving device based on a Gaussian low-pass filter and a Butterworth low-pass filter, and optimizing the receiving device in combination with a Chebyshev function; sending the converted baseband signal to the receiving device by using the channel; and segmenting the frequency band of the converted baseband signal through the receiving device, and distributing the segmented frequency band to portable mobile equipment and computer equipment to complete communication. By designing the transmitting device, the tuning speed is increased; and meanwhile, the Chebyshev filter is added with a delay weight, and a metalized via hole is added on a rectangular ring of the receiving device to optimize the receiving device, so that the delay is effectively improved, and the real-time requirement is met.

The invention provides a group distribution detection method based on a Chebyshev filter, and the method mainly comprises the following steps: reading complex network data, and abstracting a complex network into a graph model; carrying out label initialization, that is, a unique label is marked for part of nodes and used for representing a group where the nodes are located, and other nodes are notmarked; inputting the initialized nodes into a Chebyshev filter, and extracting hidden layer features of the graph model; and mapping the extracted features to a marked node space for processing, andinputting an output value into a classifier, so that the nodes with the same label are the same group. A Chebyshev filter semi-supervised learning method is used for realizing group distribution detection, fewer parameters are used for discovering the group structure of the network, and the efficiency of complex network group distribution detection is improved.

The invention discloses a chained low-pass filtering circuit. The circuit structurally comprises an inductor and a capacitor. The Butterworth flattest amplitude-frequency characteristic and the Chebyshev optimal out-of-band rejection characteristic are mainly utilized, a chained low-pass filter is a compromise of a Butterworth filter and a Chebyshev filter, and different responses are given under the same order. Compatibility of the flattest amplitude-frequency characteristic and the optimal out-of-band rejection characteristic of design of the filter is effectively achieved, and it can be ensured that a passive filter can obtain an optimal filtering effect. The important effect of a chained function is that a bridge is set up between the flattest amplitude-frequency characteristic of the Butterworth function and the traditional Chebyshev approximate high out-of-band rejection characteristic. The chained low-pass filtering circuit can be widely used on WCDMA mobile communication power amplifiers, radar antennas and other places having strict requirements for signal performance, out-of-band noise can be restrained, and stability of the electronic circuit is improved.

The invention relates to the microwave and filter technology, and particularly relates to a generalized Chebyshev SIW filter magnetic tuning method. Tuning is performed for the SIW cavity filter in the generalized Chebyshev filter. A ferrite cylinder is embedded in the region of the highest coupling in the target SIW cavity filter, then an external magnetic field is applied to the embedded ferritecylinder, the coupling coefficient is changed by adjusting the size of the external magnetic field and finally the result is changed and magnetic tuning is realized. Magnetic tuning of the SIW cavityfilter can be realized.

The invention discloses a stripline low-pass filter and aims to provide a low-pass filter with low passband attenuation, steep near-end stopband attenuation and high far-end stopband suppression. According to the technical scheme, the stripline low-pass filter is characterized in that a first-level five-order elliptic function filter unit is formed by trapezoid stripline branch nodes S1, S2 and S3which are distributed as a Y shape and two high-impedance U-shaped coupled series branch nodes W1 and W2 which are connected with the trapezoid stripline branch nodes S1, S2 and S3; a second-level five-order elliptic function filter unit is formed by trapezoid stripline branch nodes S4, S5 and S6 which are distributed as a Y shape and two high-impedance U-shaped coupled series branch nodes W3 andW4 which are connected with the trapezoid stripline branch nodes S4, S5 and S6; a ten-order Chebyshev filter unit is formed by stripline branch nodes L1, L2, L3, L4 and L5 on the same plane and T-shaped open-circuit branch nodes T1, T4 and T5 which are pairwise vertical to each other in a same direction; an input step impedance unit is formed by stripline step impedance P1; and an output steppedimpedance unit is formed by stripline step impedance P2.

The invention discloses a third-order filtering base station antenna based on a resonator type dipole. The third-order filtering base station antenna comprises a first vertical dielectric plate, a second vertical dielectric plate and a horizontal dielectric plate, wherein the first vertical dielectric plate is provided with a first resonator and a first copper-clad structure, the first copper-cladstructure and the first resonator form a first dipole, and 45-degree polarization feed is realized by a first feed port through a second resonator, a third resonator and a first coupling feed line onthe first vertical dielectric plate and the horizontal dielectric plate; a fourth resonator and a second copper-clad structure are arranged on the second vertical dielectric plate, a second dipole isformed by the second copper-clad structure and the fourth resonator, and 45-degree polarization feed is realized by a second feed port through a fifth resonator, a sixth resonator and a second coupling feed line on the second vertical dielectric plate and the horizontal dielectric plate; The antenna is advantaged in that dual polarization of the antenna is achieved, the filtering characteristic of a three-order Chebyshev filter is achieved, the polarization isolation degree is 20dB or above, and meanwhile the antenna has the advantage of being low in machining cost.

The invention relates to a high temperature resistance switching power source based on a gallium nitride device and a DSP chip and a working method thereof. The high temperature resistance switching power source comprises a closed loop control system composed of the DSP chip, a GaN transistor and a switching power source buck circuit, and the system is a single input and single output negative feedback system, the high temperature resistance DSP chip is adopted as a control chip, the GaN field effect transistor is adopted as a switch, and a Chebyshev filter circuit composed of a high temperature resistance inductors, capacitors and resistors can meet the requirement for high temperature switching power sources in the prior art.

The invention discloses an integrated method for a power divider with band-pass frequency response. The method comprises the following steps of: on the basis of the input port return loss and out-of-band suppression index for design of the power divider, integrating a corresponding normalized coupling matrix of a general Chebyshev filter; and according to the number of branches of the power divider and the power dividing ratio of each branch, by using an equivalent circuit principle, changing the coupling coefficients of the last common node of a network and a first node in each branch and the coupling coefficients of the branches including cross coupling to obtain the normalized coupling matrix of the power divider of this type, so that the aim of quickly integrating a band-pass type power divider is fulfilled. By adoption of the method, optimization of the normalized coupling matrix of the whole power divider is not required. The method is easy to implement and high in feasibility. The problem of non-convergence of the acquired normalized coupling matrix of the power divider by using an optimization algorithm or long computation time in the prior art can be solved.

The invention provides a 5G millimeter wave filtering antenna based on SIW. A radiation substrate integrated cavity SIC resonator and a non-radiation SIC resonator loaded by an ME dipole antenna are adopted to realize a Chebyshev filtering function of a coupled resonator; a dual-slot feed ME radiation dipole antenna is adopted, and a non-radiation SIC resonator is used as a support to control a radiation pattern and corresponding coupling of a filtering antenna. The antenna has the advantages of high performance, flat gain, strong filtering function, small size and the like, and can be applied to the field of 5G millimeter waves.

The invention provides a filter, which comprises a main path of the filter and an energy absorbing and coupling unit, wherein the energy absorbing and coupling unit is connected to an input end and an output end in an additional coupling manner; and the energy absorbing and coupling unit comprises two resonators which are the same or similar in frequency and have couplings. The filter provided by the invention can directly generate a pair (two) of transmission zero points through first-order additional coupling, or even generate multiple pairs of transmission zero points, so that the physical size of the filter can be greatly reduced; and meanwhile, the key problem that the filter does not have a cross coupling, but can achieve the transmission zero points of the filter is also solved. Asymmetrical distribution of the transmission zero points can also be achieved by properly adjusting the frequencies of various resonators in the energy absorbing and coupling unit; and the problem of random distribution of the transmission zero points is solved. Meanwhile, the filter provided by the invention does not have limitation on the resonator structure, so that all resonators can adopt the same shape, do not need to introduce a coupling intersection line; and the whole design process is like the design process of a traditional chebyshev filter and becomes relatively simple.

The invention relates to low-pass digital filters, and in particular relates to an active low-pass digital filter realized by using a digital processing unit. The digital processing unit adopts a 16-bit word length; a filter is an odd-order Chebyshev filter; and the order of the filter is 1 or 3. By selecting a filter with a proper order, the active low-pass digital filter can be preferably applied to the existing digital processing units at the same time of meeting requirements of stop bands.

A signal output device is provided in a communication apparatus. The communication apparatus communicates with a different one of the communication apparatus using a single line. The signal output device includes a signal output unit. The signal output unit includes a first filter and a second filter. The first filter is provided by a Bessel filter. The second filter is provided by a Chebyshev filter or a Butterworth filter. The signal output unit outputs a signal which is obtained by passing a predetermined signal through the first filter and the second filter. The signal output from the signal output unit has a pass characteristic of the first filter and a pass characteristic of the second filter. A cutoff frequency of the first filter is set to be lower than a cutoff frequency of the second filter.

The invention provides a multi-path flow meter calibrating device pulse counting signal reconstruction method. The method comprises the steps of obtaining output signals uo(t) of to-be-calibrated flow meters and a standard flow meter; analyzing the amplitude-frequency characteristics of the uo(t); selecting the first trough frequency before the signal with the maximum amplitude as the filter cut-off frequency; using an N-order high pass digital Chebyshev filter and obtaining filtered signals v(t); calculating the average period Tv and the amplitude mean square root Av of the v(t); setting the rising edge and falling edge threshold value coefficients ku and kd, the rising edge and falling edge triggering threshold values being kuAv and kdAv; recording all the rising edge triggering positions as a one-dimensional array Pu and all the falling edge triggering positions as a one-dimensional array Pd; reconstructing pulse signals u(t) according to the Pu and Pd and with the Av as the amplitude, the time delta t between adjacent rising edges (falling edges) meeting the condition of (1-3sigma)Tv<delta t<(1+3sigma)Tv, wherein sigma is the pulse output period deviation.

The invention discloses a direct and integrated design method of band-pass filters. In order to overcome the defect that the coupling matrix derived from the traditional integrated design method of the generalized Chebyshev single-pass-band or multi-pass-band band-pass filters is only narrow-band approximation and can not be used for integrated band-pass filters, the method is available for integrating the generalized Chebyshev single-pass-band or multi-pass-band band-pass filters in a band-pass domain directly, and improving the group delay characteristic in the pass band of the filter by introducing a plurality of transmission zeros. The direct and integrated design method can be used for extracting a network matrix of the generalized Chebyshev band-pass filters of the transmission zeros which have any bandwidth and are positioned at any frequency; and the derived network matrix has practical physical significance, while the network matrix derived from the traditional scheme can be taken as a low-pass narrow-band approximation result of the network matrix derived by using the method disclosed by the invention. The whole method disclosed by the invention has the advantages of simpleness, fastness and accuracy.