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40 results about "Elliptic filter" patented technology

An elliptic filter (also known as a Cauer filter, named after Wilhelm Cauer, or as a Zolotarev filter, after Yegor Zolotarev) is a signal processing filter with equalized ripple (equiripple) behavior in both the passband and the stopband. The amount of ripple in each band is independently adjustable, and no other filter of equal order can have a faster transition in gain between the passband and the stopband, for the given values of ripple (whether the ripple is equalized or not).

Arbitrary waveform generator based on PXIe bus

The invention relates to the field of signal generator, and specifically relates to an arbitrary waveform generator based on a PXIe bus. The generator comprises a waveform generation part and a waveform conditioning part. The waveform generation part comprises an FPGA and a crystal oscillator. The waveform conditioning part comprises a 16-bit DAC, an operational amplifier, an SPI program control amplifier, a filter circuit, an SPI program control DAC, a differential operational amplifier, and a subtracter. The generator employs the PXIe bus as a channel which is used by an upper computer for transmitting waveform data. The FPGA continuously process the waveform data transmitted by the upper computer in a waveform generation process, so as to guarantee the integrity of high-frequency signal quality. In a waveform conditioning process, the generator respectively employs a Bessel filter and an elliptic filter according to the frequency characteristics of signals and the difference of anti-noise capabilities, and meets the filtering requirements of different types of signals. For a signal with the amplitude being less than 50mV, a small signal processing branch circuit is designed, thereby guaranteeing that a signal with a small amplitude value cannot be flooded by noise. The generator employs a mode of internal and external synchronization adjustment for signal amplitude and bias, and guarantees the accuracy of a signal.
Owner:AVIC BEIJING CHANGCHENG AVIATION MEASUREMENT & CONTROL TECH INST +2

Parallel connection type unilateral elliptic function transmission line filter

The invention provides a parallel connection type unilateral elliptic function transmission line filter composed of transmission line elements. Input signals are fed into a first parallel connection cross joint (2) from an input transmission line (1) and divided into two paths to be transmitted to a second parallel connection cross joint (7) respectively through a cascading transmission line joint (3) and a parallel connection transmission line joint (4), and two paths of the input signals are synthesized and then output from an output transmission line (8). Two open circuit transmission line branch joints are connected to the two parallel connection cross joints respectively to adjust the amplitude of reflected signals. As for given cut-off frequency fc, various transmission line element parameters are selected, more than two nonzero limited frequency reflection null points with frequency lower than or higher than fc are generated, and a passing band is generated nearby a frequency band of the nonzero limited frequency reflection null points; meanwhile, more than two nonzero limited frequency transmission null points with frequency higher than or lower than fc are generated, a stop band is generated nearby a frequency band of the nonzero limited frequency transmission null points, and therefore filter characteristics of a unilateral elliptic function nearby fc are achieved. The filter is suitable for bandwidth below the medium degree of microwave and millimeter wave frequency bands, low loss, high selectivity.
Owner:10TH RES INST OF CETC

Sub-1G radio frequency front-end circuit design based on RF energy detection and parameter adjustment method based on RF energy detection

The invention discloses a sub-1G radio frequency front-end circuit design based on RF energy detection and a parameter adjustment method based on RF energy detection. The procedure for adjusting parameter values of components in a second-order elliptic function low-pass filter on the basis of RF energy detection specifically comprises the following steps that a channel energy value is obtained; energy loss of a wireless signal on a transmission line and the communication distance between nodes are calculated; according to the calculated energy loss on the transmission line and the communication distance between the nodes, the parameter values of the components of the second-order elliptic function filter are adjusted. The stability and the reliability of the designed Sub-1G radio frequency front-end circuit are high, the parameter values of the components in the second-order elliptic function low-pass filter can be adjusted on the basis of RF energy detection, the purpose that the transmission line and the impedance of the load are matched with the impedance of a radio frequency source is achieved by replacing the actual electronic component values of the radio frequency circuit, and transmission at the maximum transmission power is achieved.
Owner:南通森翔检测技术有限公司

Laminated sheet type low pass filter for CATV

ActiveCN103929142AEnhance high frequency quality factorImprove featuresOne-port networksLow-pass filterConductive coating
The invention discloses a laminated sheet type low pass filter for a CATV. The laminated sheet type low pass filter is small in size, low in cost and high in Q value and conductivity and is of an LTCC structure. The laminated sheet type low pass filter comprises a ceramic body and conductive coatings, wherein the ceramic body is formed by a plurality of layers of substrates made of high-frequency ceramic membranes, and the substrates are coated with the conductive coatings. Three laminated inductors formed by at least four sets of laminated sheets coated with three semi-elliptic or semicircular independent conductive coatings are arranged in the ceramic body. According to the laminated sheet type low pass filter for the CATV, the LTCC technology multi-layer structure is adopted to manufacture the seven-order low pass filter with three transmission zeros, and an original elliptic filter is adopted to improve the circuit characteristic through coupling between the laminated spiral inductors. The size of the laminated sheet type low pass filter is 3.2 mm*2.5 mm*1.0 mm, the LTCC technology is adopted, the cost is low, and mass production can be achieved. In addition, the conductive coatings on every two substrates in the laminated inductors of the low pass filter are connected in parallel, the sectional area of a coil is increased, and therefore the high frequency quality factor of the filter is improved.
Owner:SHENZHEN SUNLORD ELECTRONICS

Achieving method for low-power high-frequency ultrasonic power source

Disclosed are a low-power high-frequency ultrasonic power source and an achieving method thereof. According to the device, an experimental mode of combination of software and hardware is adopted, and a hardware part is mainly formed by a power source operation panel, an ultrasonic power source circuit, an ultrasonic vibrator and an inductor matched with the ultrasonic vibrator. The operation panel is structurally provided with a power switch key, an indicating lamp of the power switch key, a reset key, an indicating lamp of the reset key, a frequency selection key, an indicating lamp of the frequency selection key, a mode selection key, an indicating lamp of the mode selection key, a power selection key and an indicating lamp of the power selection key. The power source circuit is mainly formed by a power switch circuit, a reset circuit, a crystal oscillation circuit, a key circuit, a state display indicating lamp circuit, an elliptic filter circuit, a mode and power chopper switch circuit, a power amplification circuit and a matching network circuit. A frequency generating module, a mode setting module, a power selection module, a matching inductance switching control module and a control module of the indicating lamps of the device are achieved by software programming.
Owner:JIANGSU HUAAN SCI RES DEVICES

Method for designing arbitrary duty ratio unequal band width optical interleaver

The invention relates to a method for designing an arbitrary duty ratio Michelson Gires-Touruois interferometer type unequal bandwidth optical interleaver. The method simplifies complicated transmission of a multi-mirror GT cavity and the expression of a light wave electric vector in a reflection direction through z transform in a digital signal processing, calculates the expressions of transmission functions of two paths of output ports of the optical interleaver on the basis, and obtains the cavity length and the arm length difference of the GT cavity, and the reflectivity of each mirror surface of the GT cavity with design principle of an elliptic filter by a limit point value of a transfer function. Particularly, an even-order Michelson Gires-Tournois interferometer type optical interleaver with definite exponent number can be designed to realize the arbitrary duty ratio optical interleaver throughby respectively decomposing two paths of transmission functions of the optical interleaver into sum and difference of two all-pass filters with adjacent exponent numbers. The unequal bandwidth optical interleaver designed by the method has the characters of high flatness, high bandwidth utilization, high isolation, and the like for two paths of output spectrums. Particularly, the design method does not require programming for calculation, has simple calculation, represents better advantages for the situation of cascading a plurality of reflectors, and has wide application prospect in special wave filter, gain equalization and other fields.
Owner:SHANGHAI MUNICIPAL ELECTRIC POWER CO +1

Structure of interleaver based on cascaded optical fiber circulator and design method thereof

The invention relates to a structure of an interleaver based on a cascaded optical fiber circulator and a design method thereof, and belongs to an interleaver technology, which is used for solving the problems of the existing optical multiplexer such as poor spectral transmittance, uneven output spectrum and low isolation. In the method, frequency domains in the formulas of two output port spectrums are converted into z domains by adopting a digital signal processing mode, and then pole-zero characteristics in the z domains are analyzed; the output spectrums with equal bandwidth can be obtained only if all poles in the formulas of the output spectrums are positioned on an imaginary axis; length of various cascaded annular cavities and length difference of MZ (Mach-Zehnder) interference arms can be obtained in combination with orders of an elliptic filter; and the coupling angles of couplers for various fiber annular cavities are solved by virtue of the pole values of the elliptic filter. The interleaver with equal bandwidth designed by the method has two output spectrums which have the characteristics of high flatness, high bandwidth utilization ratio, high isolation and the like; and especially under the condition of the cascaded optical annular cavities with more stages, the interleaver has the advantages of simple computation and high accuracy.
Owner:上海宽岱电讯科技发展有限公司

Fractional order elliptic filter design method of amplitude non-attenuation equilibrium phase

The invention provides a fractional order elliptic filter design method of an amplitude non-attenuation equilibrium phase. The method specifically comprises the following steps: firstly, initializingan algorithm, designing an all-pass filter of which the amplitude is attenuated, converting the order of the elliptic filter into any positive real number from an integer, and then introducing an amplitude non-attenuation reverse filter to obtain an amplitude non-attenuation equilibrium phase; estimating that the error signal amplitude is not attenuated and the phase is a negative phase, and effectively compensating the phase of the fractional order analog filter. According to the fractional order elliptic filter design method of the amplitude non-attenuation equilibrium phase, the order adjustment of the filter becomes more flexible, due to the introduction of the reverse filter, the phase delay of the filter is effectively compensated, the linearity of the elliptic filter is improved; meanwhile, the amplitude of the filter is not attenuated, therefore, the steep transition zone characteristics of the elliptical filter are not changed, the comprehensive performance of the filter is improved, and the method has good engineering practicability.
Owner:HUAQIAO UNIVERSITY

Design method of fractional order elliptic filter with linear phase

ActiveCN111865269AImprove performanceSuperior performance filters Superior performanceDigital technique networkAlgorithmEngineering
The invention provides a design method of a fractional order elliptic filter with a linear phase. According to the method, a Bessel filter is cascaded behind a fractional order elliptic filter. The method specifically comprises the steps of: performing initialization, randomly generating an initial zero point and a pole of the fractional order elliptic filter; calculating a zero pole of the elliptic filter; performing algorithm iteration on a zero pole; outputting the optimal solution of the fractional order elliptic filter, respectively calculating the group delay of the elliptic filter and the group delay of the Bessel filter, carrying out the algorithm iteration, and finally outputting the order n of the Bessel filter and the optimal solution of the fractional order elliptic filter, thereby completing the design of the fractional order elliptic filter with the linear phase. According to the method, the nonlinear phase of the fractional order elliptic filter is compensated by utilizing the good phase characteristic of the Bessel filter, and the poor transition zone characteristic of the Bessel filter is compensated by virtue of the steep transition zone characteristic of the elliptic filter, so that the filter performance with excellent performance is obtained, and the method has good engineering practicability.
Owner:HUAQIAO UNIVERSITY

Single reactance compensation magnetic coupling resonance type wireless power transmission broadband E-type power amplifier

The invention discloses a single reactance compensation magnetic coupling resonance type wireless power transmission broadband E-type power amplifier. The working process of the single reactance compensation magnetic coupling resonance type wireless power transmission broadband E-type power amplifier is as follows: an input signal (1) passes through an input matching circuit (2) and an input reactance compensation circuit (3); a gate bias power supply (4) is connected to the front end of a power tube (6) through a power supply filter circuit (5); a feedback circuit (7) is connected to two endsof the power tube (6) in parallel; a drain power supply (8) is connected to the rear end of the power tube (6) through a power supply filter circuit (9); and the output signal of the power tube (6) passes through an output reactance compensation circuit (10), an output matching circuit (11), and a low-pass elliptic filter circuit (12). Compared with the traditional single frequency point E-type power amplifier, ideal output power and efficiency can be kept on a relatively wide frequency band; the system output frequency is convenient to adjust; only the output signal frequency of a signal generation circuit needs to be adjusted; and furthermore, due to adoption of the low-pass elliptic filter circuit, the filter property of a broadband E-type power amplifier load network is improved.
Owner:NANJING UNIV OF SCI & TECH

Double-operational-amplifier elliptic function and inverse Chebyshev active low-pass filter circuit

The invention discloses an inverse Chebyshev active low-pass filter circuit with a double-operational-amplifier elliptic function. The circuit comprises a signal input end Vs, a signal output end Vo and an input and output signal common end GND, and is characterized by further comprising a resistor Rq1, a resistor Rq2, a resistor Ra, a resistor Rb, a resistor Rd, a resistor Ri, a resistor Ro, a capacitor Ca, a capacitor Cb, an operational amplifier U1A and an operational amplifier U1B, and one end of the resistor Rq1, one end of the resistor Ri and one end of the capacitor Ca are connected to a node p1, which serves as the input end which is connected to an input signal Vi; the other end of the resistor Rq1, the other end of the capacitor Ca, one end of the resistor Rq2, one end of the resistor Ra and the in-phase input end of the operational amplifier U1A are connected to a node p2; and the other end of the resistor Rq2 is connected to the input and output signal common end GND. The circuit is good in symmetry, stable in performance and easy to design and use, one to two operational amplifiers are saved compared with a 3 or 4 operational amplifier state variable elliptic function filter, power consumption is reduced, the size of the circuit is reduced, and the cost of the filter and the circuit is reduced.
Owner:王致华

An arbitrary waveform generator based on pxie bus

The invention relates to the field of signal generator, and specifically relates to an arbitrary waveform generator based on a PXIe bus. The generator comprises a waveform generation part and a waveform conditioning part. The waveform generation part comprises an FPGA and a crystal oscillator. The waveform conditioning part comprises a 16-bit DAC, an operational amplifier, an SPI program control amplifier, a filter circuit, an SPI program control DAC, a differential operational amplifier, and a subtracter. The generator employs the PXIe bus as a channel which is used by an upper computer for transmitting waveform data. The FPGA continuously process the waveform data transmitted by the upper computer in a waveform generation process, so as to guarantee the integrity of high-frequency signal quality. In a waveform conditioning process, the generator respectively employs a Bessel filter and an elliptic filter according to the frequency characteristics of signals and the difference of anti-noise capabilities, and meets the filtering requirements of different types of signals. For a signal with the amplitude being less than 50mV, a small signal processing branch circuit is designed, thereby guaranteeing that a signal with a small amplitude value cannot be flooded by noise. The generator employs a mode of internal and external synchronization adjustment for signal amplitude and bias, and guarantees the accuracy of a signal.
Owner:AVIC BEIJING CHANGCHENG AVIATION MEASUREMENT & CONTROL TECH INST +2

Method for designing arbitrary duty ratio unequal band width optical interleaver

The invention relates to a method for designing an arbitrary duty ratio Michelson Gires-Touruois interferometer type unequal bandwidth optical interleaver. The method simplifies complicated transmissiThe invention relates to a method for designing an arbitrary duty ratio Michelson Gires-Touruois interferometer type unequal bandwidth optical interleaver. The method simplifies complicated transmissig a plurality of reflectors, and has wide application prospect in special wave filter, gain equalization and other fields.vantages for the situation of cascading a plurality of reflectors, and has wide application prospect in special wave filter, gain equalization and other fields.advantages for the situation of cascadinh utilization, high isolation, and the like for two paths of output spectrums. Particularly, the design method does not require programming for calculation, has simple calculation, represents betteradth utilization, high isolation, and the like for two paths of output spectrums. Particularly, the design method does not require programming for calculation, has simple calculation, represents betterteaver into sum and difference of two all-pass filters with adjacent exponent numbers. The unequal bandwidth optical interleaver designed by the method has the characters of high flatness, high bandwideaver into sum and difference of two all-pass filters with adjacent exponent numbers. The unequal bandwidth optical interleaver designed by the method has the characters of high flatness, high bandwidon of a multi-mirror GT cavity and the expression of a light wave electric vector in a reflection direction through z transform in a digital signal processing, calculates the expressions of transmission of a multi-mirror GT cavity and the expression of a light wave electric vector in a reflection direction through z transform in a digital signal processing, calculates the expressions of transmission functions of two paths of output ports of the optical interleaver on the basis, and obtains the cavity length and the arm length difference of the GT cavity, and the reflectivity of each mirror suron functions of two paths of output ports of the optical interleaver on the basis, and obtains the cavity length and the arm length difference of the GT cavity, and the reflectivity of each mirror surface of the GT cavity with design principle of an elliptic filter by a limit point value of a transfer function. Particularly, an even-order Michelson Gires-Tournois interferometer type optical interlface of the GT cavity with design principle of an elliptic filter by a limit point value of a transfer function. Particularly, an even-order Michelson Gires-Tournois interferometer type optical interleaver with definite exponent number can be designed to realize the arbitrary duty ratio optical interleaver throughby respectively decomposing two paths of transmission functions of the optical interleaver with definite exponent number can be designed to realize the arbitrary duty ratio optical interleaver throughby respectively decomposing two paths of transmission functions of the optical interl
Owner:SHANGHAI MUNICIPAL ELECTRIC POWER CO +1

A general psk modulation and demodulation system

The present invention discloses a universal PSK (phase shift keying) modulation and demodulation system. The system comprises a universal demodulator module, an FPGA (Field-Programmable Gate Array) chip, a modulation signal generator module, a PCI (Peripheral Component Interconnect) data bus module and a power module. The universal demodulator module comprises an interface circuit and an analog-digital converter, the interface circuit comprises an S-K filtering circuit, a voltage conversion circuit and a single-end-to-difference circuit; the FPGA chip is internally provided with a demodulationalgorithm module, a modulation algorithm module, a PCI control module and an SPI (Serial Peripheral Interface) controller; the modulation signal generator module comprises a digital upper converter,a signal output circuit and a seven-order elliptic filter; the PCI data bus module comprises a golden finger circuit board, an SDRAM (Synchronous Dynamic Random Access Memory) chip, a PCI interface chip and an EEPROM (Electrically Erasable Programmable Read-Only Memory); and the power module is connected with the golden finger circuit board. The universal PSK modulation and demodulation system canachieve rapid design and automatic code generation of the demodulation system so as to enhance the universality of the modulation and demodulation system.
Owner:法纳通电器(上海)有限公司
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