49 results about "Stopband" patented technology

This invention discloses a miniaturized, wide-stopband low-pass filter design method, covering 3D model design, simulation optimization, circuit fabrication and testing, and design verification based on dielectric integrated suspension line technology. The core of the low-pass filter design is based on dielectric integrated suspension line technology. Furthermore, the core circuit of this filter employs three layers of surface-mount capacitors and a double-layer spiral inductor to reduce circuit size, while combining a honeycomb structure to extend the stopband. Compared to traditional circuit designs, the implemented filter exhibits self-encapsulation characteristics, achieving low insertion loss and an ultra-wide stopband range, providing an important basis for filter performance optimization.

The invention provides a high-suppression passive reconfigurable intermediate-frequency filter based on a GaAs process, which comprises a high-order reconfigurable low-pass filter unit and a high-order reconfigurable high-pass filter unit which are in cascade connection, and is characterized in that the high-order reconfigurable low-pass filter unit is designed based on a seven-order low-pass elliptic function prototype and comprises a series branch and a parallel branch; the parallel branch comprises an adjustable capacitor and an inductor connected in series, bandwidth mode switching is achieved by adjusting the position of a transmission zero point, a fixed LC resonance circuit is introduced into the series branch to generate a fixed transmission zero point, and out-of-band rejection is enhanced; the high-order reconfigurable high-pass filter unit is designed based on a seven-order high-pass elliptic function prototype and comprises a series capacitor and a parallel grounding branch, and the parallel grounding branch comprises an inductor and an adjustable capacitor which are connected in series and is used for introducing a transmission zero point of a low-frequency stop band. According to the scheme, low insertion loss is kept while bandwidth mode switching is achieved, and the far-end out-of-band rejection capacity is remarkably improved.

The application provides a high-selectivity and simple-structure filter power amplifier and radio frequency integrated circuit, and relates to the field of power semiconductor devices.The application provides stable gate and drain bias voltages for the power amplifier transistor through a gate DC bias network and a drain DC bias network, and guarantees stable operation of the device.The input end and the output end impedance matching network are symmetrically arranged around the power amplifier transistor, both of which contain the same filter impedance transformer, and the layout is compact and simple, without additional independent filter module, effectively simplifying the circuit structure and improving the miniaturization level.Further, the filter impedance transformer is formed by cascading two λ / 4 parallel coupled microstrip lines and is matched with a λ / 2 open microstrip line, and based on the transmission line impedance transformation principle, the filter impedance transformer realizes fundamental real impedance matching, reduces signal transmission loss, forms transmission zero points in the stop band, and significantly improves the frequency selectivity.The overall circuit has high integration, excellent performance, and good engineering application and promotion value.

This invention discloses a cross-shaped microstrip filter, belonging to the field of microwave RF passive device technology. The filter includes a dielectric substrate, an input microstrip line, an output microstrip line, two sets of series-arm resonant units, and two sets of parallel-arm resonant units. The series-arm resonant units are composed of microstrip inductors and interdigital capacitors connected in series, with the resonant frequency corresponding to the filter's center frequency. The parallel-arm resonant units are composed of microstrip inductors and surface-mount capacitors connected in series, generating low-frequency and high-frequency transmission zeros respectively. The four sets of resonant units converge at a common node to form a cross-shaped topology. This invention, through a modular cross-shaped architecture, allows direct mapping between the resonant units and the frequency response, simplifying debugging and increasing design efficiency. Modular cascading can achieve high-order filtering, significantly improving band-edge steepness and stopband suppression, making it suitable for microwave RF systems such as communication, radar, and satellite navigation.

This invention proposes an adjustable complex terminal impedance bandpass filter with extended bandwidth, belonging to the field of wireless communication technology. The output terminal of the first dual-mode resonator DMR1 and the input terminal of the second dual-mode resonator DMR2 are connected in series via a tenth DC blocking capacitor and a second coupling capacitor C23. The input terminal of the first dual-mode resonator DMR1 is connected to an external source via a ninth DC blocking capacitor and a first coupling capacitor CS1, serving as the first port. The output terminal of the second dual-mode resonator DMR2 is connected to a load via an eleventh DC blocking capacitor and a third coupling capacitor C4L, serving as the second port. A first LC series resonator is connected in parallel between the first port and the first coupling capacitor CS1; a second LC series resonator is connected in parallel between the second port and the third coupling capacitor C4L. This invention enhances the stopband rejection capability of the bandpass filter, further extends the impedance tuning range within a certain filter bandwidth, and also exhibits high out-of-band rejection and low loss performance.

The application discloses a band-pass filter, and relates to the field of microwave technology.The band-pass filter comprises a first shielding layer, a resonant coupling layer and a second shielding layer which are sequentially arranged from top to bottom and are made of a low-temperature co-fired ceramic process.The resonant coupling layer comprises a first coupling line, a second coupling line, four resonators arranged from left to right and three couplers;one coupler is arranged between every two adjacent resonators;the first coupling line is located above the resonators at the leftmost end and the rightmost end;the second coupling line is located below the two resonators in the middle;the resonators and the couplers are connected with ground ports;the resonator at the leftmost end is connected with an input port;the resonator at the rightmost end is connected with an output port;the first shielding layer and the second shielding layer are connected with the ground ports.The application can make the relative bandwidth of the passband less than 10%, and improve the passband performance and the stopband suppression performance.

This invention proposes a high-performance LC high-pass filter, comprising a signal input terminal, a signal output terminal, and a common ground terminal, and further comprising a first resonant unit, a second resonant unit, a third resonant unit, a fourth resonant unit, and a fifth resonant unit connected in sequence. This invention can be used in carrier aggregation scenarios to suppress blocking interference caused by low-frequency transmitted signals to high-frequency receivers, while allowing high-frequency signals to pass through without distortion. Its steep stopband characteristics ensure extremely high suppression even at frequencies very close to the passband, effectively protecting sensitive receiving circuitry. By employing a Π-type capacitor network structure, the bandwidth of the high-pass filter is extended by 6%. Furthermore, the integrated design reduces its physical size by approximately 10%, making it highly suitable for space-constrained system applications.

This invention belongs to the field of microwave antenna and RF front-end circuit technology, specifically relating to a broadband filter dielectric resonator antenna with wide harmonic suppression characteristics and a method for controlling its radiation characteristics. The method includes the following steps: obtaining an initial electromagnetic state parameter set and performing fundamental mode field distribution decoupling calculations; constructing an open-loop feeder partially coupled topology to generate a hybrid broadband response signal set; parsing the passband envelope and attenuation determination to map a folded open-loop resonator to generate lower stopband zeros; determining the harmonic frequency band energy density threshold to trigger a multi-topology notch filter to generate an upper stopband zero array; and compensating for phase group delay and gain flatness to output the converged final radiation state parameters of the antenna. This invention overcomes the problems of multimode interference between the feed network and the radiator, the inability to independently generate stopband radiation zeros, and nonlinear phase group delay shift caused by the lack of distributed notch filter node cooperative configuration.

The application relates to an acoustic metamaterial with a frequency-doubling filtering characteristic and a shape optimization method thereof, the optimization method comprising the following steps: constructing a two-dimensional finite element simulation model, the two-dimensional finite element simulation model comprising a main plate, a thin adhesive layer and an acoustic metamaterial, the acoustic metamaterial having an initial structure, the initial structure being periodically arranged by an initial unit cell structure, and a free-shape boundary being arranged in the initial structure; constructing an optimization model according to a target that a fundamental frequency is a passband and a frequency double is a stopband; adjusting the free-shape boundary on the basis of the initial structure by using a moving asymptote method; and calculating to obtain an optimal structure of the acoustic metamaterial. Compared with the prior art, the application not only ensures that the optimization target can be achieved, but also reduces the complexity of the structure, facilitates processing and manufacturing, and the designed acoustic metamaterial has the frequency-doubling filtering characteristic, and can effectively filter the inevitable system nonlinearity in nonlinear ultrasonic Lamb wave detection.

The application discloses a four-mode reconfigurable microstrip line filter integrated with reflection-free and multi-zero-point response, which adopts a single microstrip circuit topology with left-right symmetry and is composed of an upper branch band-pass filter circuit, a T-shaped joint structure, a pair of cross-shaped absorption branches, a pair of coupled line absorption branches, five groups of switch pairs and input and output ports; the coupled lines at the two ends of the upper branch band-pass filter circuit are connected with the ground through the switch pair connection ports and the T-shaped joint structure, and the absorption branches are connected with the ports in parallel through the switches; the four-mode switching of double-band rejection, full-band reflection-free band-pass, full-band reflection-free band-stop and multi-transmission zero-point band-stop is realized in the same circuit through the on-off control of the switches; the integration degree is improved; the reflection-free characteristic of the band-stop energy dissipation is realized by relying on the resistance-loaded absorption branches; the frequency selectivity and the band-stop suppression capability are strengthened in combination with the multi-transmission zero points; and the problems of low resource reuse rate, lack of reflection-free characteristic and uneven multi-mode performance of the traditional structure are solved.

The present specification relates to the field of signal measurement, and discloses a test method and system for high-power transmitter products to solve the problem of insufficient accuracy of harmonic and spurious amplitude measurement results of high-power transmitters in the prior art. The present application comprises: sequentially connecting the to-be-tested transmitter, the high-power attenuator and the EMI receiver through a cable; making the to-be-tested transmitter output a preset working signal; adjusting the scanning parameters of the EMI receiver to obtain the maximum indication value of the fundamental power level; replacing the high-power attenuator with a band-stop filter suitable for the frequency band to suppress the fundamental amplitude and obtain the transmission signal; scanning to obtain the antenna port harmonic and spurious conducted emission level; and comparing the preset test standard to obtain the test result. The present application improves the test method, effectively improves the measurement and evaluation of the antenna port harmonic and spurious conducted emission level of the key transmitter product, and improves the accuracy and operability of the laboratory in the antenna port conducted emission test process.

The application provides a double-passband band-pass filter with independently controllable cutoff frequency based on effective artificial surface plasmon, which comprises a dielectric substrate, the upper and lower surfaces of the dielectric substrate are respectively formed with a dielectric substrate top layer and a dielectric substrate bottom layer, the dielectric substrate top layer is provided with a first microstrip line, a second microstrip line, an equivalent artificial surface plasmon double-passband band-pass filter based on a mixed substrate integrated waveguide structure, a third microstrip line and a fourth microstrip line, one end of the first microstrip line is a feeding port and is connected with a ground metal layer through a first microwave high-frequency connector joint, the other end of the first microstrip line is sequentially connected with a metal ground layer through the second microstrip line, the equivalent artificial surface plasmon double-passband band-pass filter based on the mixed substrate integrated waveguide structure, the third microstrip line, the fourth microstrip line and a second microwave high-frequency connector joint; the application can realize a band-pass filter with a wide passband, low loss, independently controllable cutoff frequency, stable stopband and deep out-of-band suppression capability.

The application discloses an ultra-wideband harmonic suppression dipole antenna, which comprises a dielectric substrate and two dipole arms with structural symmetry, an upper arm and a lower arm, the upper arm and the lower arm are respectively printed on the upper and lower surfaces of the dielectric substrate, and the upper arm and the lower arm are connected by using a through hole at the center of the dipole antenna; the fifth mode is regulated by loading a branch perpendicular to the dipole arm, so that the current zero point of the fifth mode is coincided with the current zero point of the third mode; a one-to-two T-shaped microstrip power divider is used for feeding, the output end of the power divider is connected to the common zero point position of the third resonant mode and the fifth resonant mode, so that the third resonant mode and the fifth resonant mode are filtered; and the parallel distributed capacitance at the dipole feeding point is used for filtering the seventh mode and the ninth mode. The harmonic suppression frequency of the antenna covers 10f0. At the center frequency of 1.2 GHz, the antenna has an 8-shaped E-plane and an omni-directional H-plane radiation pattern.

The application belongs to the technical field of wireless communication and electronic engineering, and particularly relates to a wideband low-noise amplifier with a frequency domain selection function, which comprises an input direct-current isolation matching network, a first-stage amplification part, an inter-stage high-pass matching network, a second-stage amplification part and an output low-pass matching network which are sequentially connected in series. Through a multi-pole-zero topology design, the wideband rejection, high port isolation, high integration and high selectivity are synergistically optimized. Within the target passband of 8-12 GHz, three transmission poles in the passband ensure excellent gain flatness, and the noise coefficient is stabilized at 0.994-1.101 dB; one transmission zero point is arranged in the lower stopband (<8 GHz) and the upper stopband (>12 GHz) respectively, the low-frequency suppression depth is greater than or equal to 50 dB, and the high-frequency suppression depth is greater than or equal to 30 dB; at the same time, the input return loss is greater than or equal to 11 dB, the output return loss is greater than or equal to 18 dB, and the port matching and isolation performance are excellent. The application is based on a GaAs 0.15 mu m MMIC planar integration process, and compared with a discrete cascade scheme, the volume is reduced by 60%, which is suitable for the development trend of high integration and miniaturization of a radio frequency front end, and can be widely applied to 5G millimeter wave communication, satellite navigation, radio frequency radar and other radio frequency front end systems with extremely high requirements for receiving sensitivity and anti-interference ability.

This invention belongs to the field of signal processing and provides a method, system, device, and medium for non-destructive testing of bearing wear faults in asynchronous motors. The method includes: performing variational mode decomposition on the stator current signal to obtain multiple modal components; adaptively identifying the fundamental frequency component of the current and obtaining the fundamental frequency using the correlation coefficient method; reconstructing the non-fundamental frequency signal after removing the fundamental frequency component; constructing a band-stop filter with multiple stopbands to dynamically suppress the fundamental frequency of the current and its integer harmonics to obtain a denoised signal; and performing envelope spectrum analysis on the denoised signal to determine the fault type by detecting whether there are spectral peaks in the envelope spectrum that match the characteristic frequency of the bearing fault. This invention effectively solves the problem of strong power frequency interference drowning out weak bearing fault characteristics through adaptive fundamental frequency identification, non-fundamental frequency reconstruction, and multi-stopband filtering, achieving high-sensitivity and high-reliability non-destructive testing without additional sensors.

This invention provides a method, apparatus, processor, and storage medium for object detection based on lidar. The method further includes: transmitting signal light emitted by a laser to a target object via optical devices and an optical phased array transceiver; detecting end-face reflection signals and target reflection signals, wherein the end-face reflection signal is formed by reflection from the optical phased array transceiver and optical devices, and the target reflection signal is formed by reflection from the target object; determining the spectral distance between the end-face reflection frequency and the target reflection frequency based on the end-face reflection signal and the target reflection signal; adjusting the spectral distance if it is less than a distance threshold; determining the passband frequency and stopband frequency of a filter based on the adjusted spectral distance; filtering out the end-face reflection signal from the target reflection signal according to the passband frequency and stopband frequency; and detecting the position of the target object based on the filtered target reflection signal. This invention solves the technical problem of inaccurate target object position information detection.

The application discloses a zero intermediate frequency satellite communication signal processing method and system based on an embedded microcontroller, and the method comprises the following steps: encoding and framing original data, generating I / Q digital baseband waveforms through QPSK mapping, upsampling and shaping filtering, and converting analog signals through a double-channel DAC. In view of Sinc fading and adjacent channel leakage caused by the zero-order holding effect of the DAC, two-stage cascade suppression is adopted: the first stage of attenuation is performed in the digital domain; the second stage of physical filtering is performed in the analog domain between the DAC and the mixer by using the stop band notch characteristic of the symmetrical active differential low-pass filter circuit, and the independent direct current bias adjustment is used for IQ balance adjustment to eliminate the carrier leakage. Finally, the mixer is used for one-step up-conversion, and a power amplifier is used for emission. The method does not need closed-loop digital IQ correction, significantly reduces resource consumption, and improves the adjacent channel power ratio and radio frequency quality.

The present application relates to the technical field of communications. Disclosed in the present application are an antenna, an antenna array, a wireless communication module and a terminal. The antenna comprises a first radiator and a second radiator, the first radiator and the second radiator being connected to a common feed point. The operating passband of the antenna comprises the resonant frequency of the fundamental mode of the first radiator. The resonant frequency of the fundamental mode of the first radiator is different from the resonant frequency of the fundamental mode of the second radiator. In a frequency band between the resonant frequency of the fundamental mode of the first radiator and the resonant frequency of the fundamental mode of the second radiator, the first radiator and the second radiator form equal-amplitude anti-phase currents. Therefore, the current of the first radiator and the current of the second radiator can cancel each other out, thereby forming a radiation null, the radiation null being used for constituting an operating stopband of the antenna. The antenna has a good suppression effect on signals of the operating stopband, such that the degree of coupling between the antenna and other antennas in the operating stopband is small, and the degree of isolation is high, thereby avoiding interference between the antennas.

The application discloses a miniaturized broadband SIW filter for satellite communication. The SIW structure is adopted as a design basis, and the quarter-mode substrate integrated waveguide and the composite left-hand / right-hand structure are adopted to realize miniaturization of the radio frequency filter. In addition, the electromagnetic bandgap structure is adopted to realize strong suppression effect, high selection characteristic and wideband characteristic on the stop band. Main modules of the filter include a feed port of an electromagnetic bandgap (EBG) structure, a SIW resonant cavity, an inductive coupling window module and a CRLH structure. A tapered line is adopted for impedance matching of input / output ports, and in addition, a gap structure is etched on the input / output ports to realize EBG loading. The QMSIW cavity part is cut according to the symmetry of electromagnetic wave distribution, and the volume of the QMSIW is reduced to one fourth of the whole SIW structure. The CRLH structure loading is realized by using the interdigital structure, and the EBG structure is loaded on the interdigital metal.

This invention discloses a low-pass, wide-stopband, large-angle stable dual-polarized frequency selective structure, radome, and antenna system. It includes two low-pass frequency selective layers, each comprising horizontal and vertical components arranged perpendicularly to each other. Each horizontal and vertical component includes two basic components and an outer dielectric plate with a cutout between them. The basic components include an inner dielectric plate with a cutout and L-shaped conductive geometries on both sides. Each side of the inner dielectric plate has edge metal strips along its length, divided into multiple segments. A middle metal strip is located at each slot in the inner dielectric plate. The middle metal strip connects to a corresponding edge metal strip segment to form an L-shaped conductor. Multiple L-shaped conductors constitute the L-shaped conductive geometry. This invention solves the problems of existing technologies that cannot simultaneously guarantee low insertion loss in the passband, ultra-wide stopband, large-angle stability, dual polarization, and poor suppression of electromagnetic waves outside the operating frequency band. Furthermore, it is easy to manufacture.

This invention provides an end-fire Vivaldi filter antenna with independently controllable cutoff frequency based on an equivalent artificial surface plasmon polariton (ESP). It comprises a dielectric substrate, with a top layer and a bottom layer formed on the upper and lower surfaces of the substrate, respectively. The bottom layer has a ground metal layer. An ESP bandpass filter based on a hybrid substrate integrated waveguide structure is embedded in the middle of the substrate. The top layer has a first microstrip line, a second microstrip line, and a first Vivaldi antenna. One end of the first microstrip line serves as the antenna feed port and is connected to the ground metal layer via a microwave high-frequency connector. The other end of the first microstrip line is connected to the first Vivaldi antenna sequentially via the second microstrip line and the ESP bandpass filter based on the hybrid substrate integrated waveguide structure. This invention enables independent control of the passband cutoff frequency and out-of-band cutoff frequency, exhibiting independently controllable bandwidth, stable stopband, and deep out-of-band suppression capabilities.

This application relates to the field of communication technology, and more particularly to a balanced cavity filter. The balanced cavity filter includes multiple cylindrical cavities and coupling windows, with adjacent cylindrical cavities symmetrically arranged with respect to the coupling windows. Each cylindrical cavity includes two resonant units, which are inverted relative to each other. Each resonant unit includes a coaxial sleeve and a coaxial inner pillar, with the inner pillar disposed within the inner cavity of the coaxial sleeve. The balanced cavity filter also includes multiple feed probes, each corresponding to one of the resonant units. The balanced cavity filter provided by this application has a wider stopband and better common-mode rejection.

Provided is a tunable frequency selective surface (FSS) structure, including: a dielectric substrate and a rectangle resonant component arranged on the dielectric substrate. The rectangle resonant component includes a plurality of perforated rectangle resonant units arranged in a matrix; the perforated rectangle resonant units each include two identical rectangle perforated metal patches, and a varactor diode arranged between the two rectangle perforated metal patches, where the two rectangle perforated metal patches are arranged in a mirror image relation. In the rectangle resonant component, the varactor diodes in the perforated rectangle resonant units in the same row are arranged in a same direction, and the varactor diodes in the perforated rectangle resonant units in adjacent rows are arranged in opposite directions. The present application can achieve the continuous tunable performance of a stopband in a specific frequency band.

This invention discloses a Ka-band miniaturized filter based on LTCC technology, comprising a ground plane; an input electrode, an output electrode, and multiple ground electrodes are disposed below the ground plane; a first resonator to a third resonator are disposed above the ground plane; one end of the first resonator is connected to an input port via an input tap, and the input port is connected to the input electrode; one end of the third resonator is connected to an output port via an output tap, and the output port is connected to the output electrode; four independently distributed U-shaped tuning capacitors are disposed between the first to third resonators and the ground plane. This invention uses U-shaped tuning capacitors to precisely control out-of-band characteristics and improve stopband rejection capability. The filter has a passband range of 17.7–21.2 GHz, an insertion loss of less than 1 dB, and a stopband rejection greater than 45 dB, with a maximum of 60 dB, exhibiting advantages such as small size, low loss, and strong rejection.