22results about How to "Improve frequency selectivity" patented technology

The present invention discloses a multi-input multi-output magnetic dipole antenna, comprising a first submodule and a second submodule, wherein the first submodule and the second submodule are electrically connected, the first submodule has a plurality of back-to-ground coplanar waveguide ports and a first waveguide resonator; the second submodule has a plurality of second waveguide resonators and a magnetic dipole antenna; the first waveguide resonator is configured to form a vertical connection structure with the second waveguide resonator to achieve a second-order filtering frequency response; the back-to-ground coplanar waveguide port is configured to form a cross-coupling structure with the magnetic dipole antenna to achieve two radiation zero points and improve frequency selectivity; a plurality of the magnetic dipole antennas are arranged so that at least two are placed in parallel, and at least one of the magnetic dipole antennas is orthogonal to the at least two parallel magnetic dipole antennas; the multi-input multi-output magnetic dipole antenna can achieve high frequency selectivity and high isolation.

The invention belongs to the technical field of polarization conversion metasurfaces, and particularly provides a high-frequency-selectivity reflective polarization conversion metasurface with fourth-order response, which is used for realizing a polarization converter with high polarization conversion rate. The half-wavelength micro-strip resonator is composed of a frequency selective surface (FSS) and a coupling layer, a coupled half-wavelength micro-strip resonator is composed of an L-shaped micro-strip line of a bottom metal layer and a through hole, response is expanded to a high order, the polarization conversion rate is increased, and the broadening bandwidth is increased; meanwhile, the middle metal layer introduces a polarization conversion zero point, thereby improving the frequency selection characteristics of the two sides of a transmission frequency band. Moreover, the polarization metasurface is rotationally symmetrical in structure, has a dual-polarization conversion characteristic, and has a relatively high application value in the aspect of electromagnetic wave polarization conversion.

The invention discloses a satellite internet integrated plane millimeter wave oscillator based on a glass-based material, and belongs to the field of microwave circuit design. The oscillator comprises a DGS resonance module based on a glass substrate, two paths of same sub-oscillator modules, duplexer modules and a combiner module, wherein the two paths of sub-oscillator modules share the same DGS resonance module based on the glass substrate, and outputs of the two paths of sub-oscillator modules are respectively connected with the two duplexer modules; and the output with higher frequency is synthesized by the combiner module to form total output. The DGS resonance module adopts a glass-based process and has the advantages of miniaturization, low loss and low cost; the two sub-oscillators share one resonator module, strong coupling is achieved, and phase noise can be optimized; the duplexer module separates fundamental waves from second harmonics, so that good matching can be realized, and spurious suppression is improved. The LED lamp is easy to process, low in cost, good in heat dissipation performance and capable of effectively achieving miniaturization and integration.

The invention relates to the technical field of tunable N-path filters, in particular to an adjustable N-path non-reflection filter and a superheterodyne receiver, the adjustable N-path non-reflection filter comprises a signal source, an N-path band-pass filtering unit, an N-path band-stop filtering unit, an output resistor and a split-phase clock generation circuit; wherein the output end of the signal source is connected with one end of the N-path band-pass filtering unit and one end of the N-path band-stop filtering unit, the other end of the N-path band-stop filtering unit is connected with the output resistor, and the split-phase clock generation circuit is connected with grid electrodes of a plurality of MOS switches in the N-path band-pass filtering unit and the N-path band-stop filtering unit and outputs control signals. The adjustable N-path non-reflection filter provided by the invention has excellent frequency selectivity, can effectively suppress higher harmonics, and can adjust a pass band and a stop band by changing the switching frequency. Meanwhile, the filter can eliminate reflected signals and prevent the reflected signals from inducing a mixer and a high-gain amplifier in a system to generate intermodulation interference and gain fluctuation.

The invention relates to a filter and an electronic device. The filter comprises a substrate, a first resonator, a second resonator, a third resonator and a fourth resonator, and further comprises a capacitive structure, a first transmission end coupled with the first resonator, and a second transmission end coupled with the second resonator. A plurality of coupling paths are formed among the first capacitive structure, the second capacitive structure, the third capacitive structure and the resonator, so that a plurality of out-of-band transmission zeros can be realized, and the frequency selection performance is excellent. The internal layout of the filter is very compact, and the miniaturization performance is outstanding.

The invention discloses a filter and an electronic device, and the filter comprises an element body which is formed by stacking one or more dielectric layers along a stacking direction; the multi-layer resonators comprise a first multi-layer resonator, a second multi-layer resonator and a third multi-layer resonator, and each multi-layer resonator comprises a first conductor structure, a second conductor structure, a third conductor structure and two path conductors; a first signal transmission end and a second signal transmission end, the first signal transmission end is coupled with the first multilayer resonator, and the second signal transmission end is coupled with the second multilayer resonator; and a coupling capacitive structure formed by coupling metalized electrodes formed inside the element body or on the surface of the element body, the coupling capacitive structure being disposed on a coupling path between the first multilayer resonator and the second multilayer resonator. The first multi-layer resonator is coupled with the second multi-layer resonator, and the third multi-layer resonator is simultaneously coupled with the first multi-layer resonator and the second multi-layer resonator.

The invention provides a Q-value-variable bisecond-order filter based on resistance feedback, and belongs to the technical field of radio frequency receivers. Differential source followers are adopted to form a second-order filtering unit, a cross coupling resistance network is introduced between differential signal nodes, and a novel method for adjusting the quality factor of the filter is provided. The quality factor Q of the filter can be independently adjusted through an equivalent feedback path formed by the cross coupling resistor in a differential working state. In addition, a parasitic zero offset method is provided, negative capacitance is achieved by cross-coupling two capacitors between differential input and output nodes, and the stop-band suppression performance is improved. On the premise that the power consumption of the filter is not increased, the variable Q value and high linearity are realized, and the structure is suitable for a radio frequency receiver system and has a good engineering application prospect.

The utility model relates to cable detection technical field discloses a signal receiving circuit and receiver, line finder for line finder, this signal receiving circuit can include probe interface, radio chip, clock supply circuit, for any cable of detection, the cable one end access line finder's transmitter's cable interface, when the receiver probe of probe interface access detects the other end of the cable, radio chip can receive the line signal of line finder's transmitter transmission and generate audio signal, the audio signal of generation is given receiver's main control chip, and main control chip controls audio output device to output sound after receiving audio signal, to prompt line search result. Visible, the utility model can apply radio chip to the receiver of line finder, can simplify circuit structure on the basis of realizing signal reception, and the integration level is high, reduces its to the occupation of circuit board volume.

The invention relates to a filter. The filter comprises a laminated body, a space coupling resonance structure, a zigzag type three-dimensional resonator, a first coupling structure, a second coupling structure, a third coupling structure, a first signal terminal and a second signal terminal. The size of the filter is smaller than that of a plane resonance unit, and miniaturization of the filter is facilitated; a higher quality factor is easy to realize, and excellent out-of-band rejection can be realized; and excellent out-of-band rejection performance is realized. The filter is very compact in internal structure and outstanding in miniaturization performance.

The present invention discloses a miniaturized high-pass filtering dual-polarized patch antenna, comprising a reflective floor, a first metal sheet and a second metal sheet. The first metal sheet and the second metal sheet are both square structures with four corners cut off and a gap in the middle. The reflective floor is a square structure. The gaps in the middle of the two metal sheets are formed by a combination of a square and a cross structure; the square gap and the cross gap are both located in the center of the metal sheet, the four branches of the cross gap and the four corners of the square gap point to the edge center of the metal sheet, the size of the cross gap is close to the edge of the metal sheet, and the patch antenna feeds the first metal sheet through four centrosymmetric metal probes. The present invention can achieve a good high-pass filtering effect and a high-pass filtering effect by digging gaps in the center of the parasitic patch and the feeding patch, and can also change the equivalent path of the current on the radiation patch, thereby achieving a miniaturized effect.

The invention discloses a dual-passband filter based on a dual-mode ring resonator and a design method of the dual-passband filter. The input and output feeder lines are located on the top layer of the dielectric substrate, the two cascaded transmission lines and the dual-mode annular resonator are connected with the input and output feeder lines, the vertical parallel short-circuit stub line and the bent parallel open-circuit stub line are connected, and the metal grounding plate is located on the bottom layer of the dielectric substrate. Wherein the annular resonator is composed of a pair of vertical coupling lines and two transverse transmission lines. The two coupling lines and the transverse transmission line on the upper side form a signal path, meanwhile, the transverse transmission line on the lower side serves as another signal path, signal cancellation is achieved through the 180-degree phase difference, and the dual-passband characteristic is achieved. The dual-mode ring resonator and the parallel open-circuit stub can realize seven transmission zeros, thereby effectively improving the frequency selectivity. In addition, the invention further provides a comprehensive design method, the optimal characteristic impedance value can be obtained, the design efficiency is fully improved, and universality is achieved.

The invention belongs to the field of semiconductor device integration, and particularly relates to a monolithic integrated frequency conversion circuit with image rejection switching and a superheterodyne system, which comprise a radio frequency power division and synthesis unit, a mixer A unit, a mixer B unit, a local oscillator phase switching unit, an intermediate frequency phase switching unit and an intermediate frequency power division and synthesis unit, wherein the mixer A unit and the mixer B unit adopt the same circuit structure and parameters, numerical control phase shifters and phase shift control units are integrated in the local oscillator phase switching unit and the intermediate frequency phase switching unit, and the two branches are enabled to reach a state of relatively leading 90 degrees or lagging 90 degrees in phase by controlling the switching state of switches in the phase shift control units. According to the invention, the mirror image rejection function is realized in two modes that the radio frequency is higher than the local frequency and the radio frequency is lower than the local frequency. After the monolithic integrated frequency conversion circuit is applied to a superheterodyne system, the monolithic integrated frequency conversion circuit has better frequency selectivity, interference resistance and low spurious characteristics.

The utility model discloses a KU wave band band-pass waveguide filter comprising a lower seat which is internally provided with a ripple filtering groove penetrating through two sides; the upper cover is buckled at the top of the lower seat and is fixed, so that the corrugated filtering grooves are encircled to form a single filtering channel; the input end is arranged at one end of the filtering channel; the output end is arranged at the other end of the filtering channel, and the filtering channel can be communicated end to end under the action of the input end and the output end; the impedance transformer is arranged at the input end of the filtering channel; the impedance transformer comprises at least two right-angle bosses formed on one side wall of the lower seat. According to the KU wave band band-pass waveguide filter provided by the utility model, through the arrangement of the lower seat and the upper cover, a single filtering channel can be formed between the input end and the output end, and the inner side plane of the upper cover is attached to the top of the lower seat for assembly, so that the filtering channel can be formed, and meanwhile, the overall size can be reduced.

The invention discloses an LTCC (Low Temperature Co-Fired Ceramic) duplexer optimization method, which relates to the field of LTCC duplexers, and adopts a multimode resonator to excite a plurality of resonant modes and collect frequency data of each mode, so that the resonant modes can be adjusted more flexibly to introduce a plurality of transmission zeros, and the frequency selectivity and suppression performance of the duplexer are remarkably improved. By coordinating the resonant mode and the coupling structure of the multi-mode resonator, the scheme can realize accurate control of transmission zero point characteristics, including frequency, depth and bandwidth.

The application relates to the technical field of radio frequency wireless communication, in particular to a center frequency and bandwidth reconfigurable power amplifier, which comprises an input port, an input matching network, a stabilizing network, a transistor, a dynamic impedance matching network, a varactor diode DC bias, a reconfigurable band-pass filter network and an output port. The output matching network is designed, the varactor diode junction capacitance adjustable characteristic is utilized to realize the continuous adjustment of the center frequency and bandwidth of the reconfigurable band-pass filter network passband and the dynamic impedance matching between the reconfigurable band-pass filter network and the transistor drain, so that the continuous reconfiguration of the center frequency and bandwidth of the power amplifier is realized, the demand of the multi-frequency band operation of a communication system is met, the frequency adjustable flexibility is improved, the continuous adjustable frequency band range is increased, the frequency selectivity and the power amplifier efficiency are improved, the system complexity is reduced, and the reconfiguration cost is reduced.

The invention discloses a multiband microwave metasurface absorber, and relates to the technical field of microwave functional devices, the multiband microwave metasurface absorber comprises a plurality of unit structures which are periodically arranged, and each unit structure comprises a metal grounding layer, an intermediate dielectric layer and a top metal resonance structure which are arranged from bottom to top; the top metal resonant structure comprises a peripheral closed ring and a metal cross-shaped structure arranged in the center of the peripheral closed ring, and the peripheral closed ring is formed by connecting four square metal rings end to end; the size of each square metal ring and the size of the metal cross-shaped structure are configured to enable the absorber to excite at least two resonance absorption peaks with the quality factors larger than 400 in the microwave frequency band of 8 GHz to 20 GHz. The dual requirements of multi-band coverage and high-frequency selectivity are met at the same time.

This invention discloses a distributed LC resonant network Ku-band on-chip tunable low-pass filter. The filter includes an RF signal entering from port 1, flowing sequentially through five high-impedance microstrip lines. These five transmission lines are equivalent to five series inductors at high frequencies. At the nodes of adjacent microstrip lines, four high-impedance microstrip lines and four sets of capacitor switch arrays are connected in parallel. Each high-impedance microstrip line with a series capacitor switch array forms a parallel resonant circuit to ground. Two low-impedance open-circuit microstrip lines are connected in parallel at the input and output ports, respectively. The parasitic capacitance generated at high frequencies is used for impedance matching of the filter. The overall topology is equivalent to an eleventh-order Chebyshev low-pass filter. Compared to existing tunable on-chip low-pass filters, this invention's low-pass filter achieves adjustable cutoff frequency across the entire Ku-band, providing a wide tuning range while ensuring excellent overall performance such as high frequency selectivity, low loss, sufficient out-of-band rejection, and miniaturization.

The invention relates to a multi-mode coupling broadband filtering antenna based on a substrate integrated waveguide, and belongs to the field of wireless energy transmission. The antenna comprises a bottom-layer metal floor, a middle-layer dielectric substrate, an upper-layer metal floor and four groups of cavity columns, the bottom-layer metal floor is arranged on the lower surface of the middle-layer dielectric substrate, and a pair of U-shaped grooves are formed in the center of the bottom-layer metal floor; a feed hole is formed in the U-shaped groove; the upper-layer metal floor is arranged on the upper surface of the middle-layer dielectric substrate, and a square groove is etched in the upper-layer metal floor; a square microstrip patch is arranged in the square groove; the four groups of cavity columns penetrate through the bottom layer metal floor, the middle layer dielectric substrate and the upper layer metal floor to define a square SIW cavity.

The present invention provides a four-frequency common-aperture circularly polarized antenna structure unit and its array, which provides four different operating frequencies for the antenna structure unit by setting four antenna units from two frequency bands through the common aperture, and improves the utilization rate of spectrum resources while maintaining the miniaturization of the antenna structure unit. Specifically, the present invention realizes the circular polarization characteristics while reducing the overall size of the antenna unit by respectively setting angle-added and / or angle-cut radiation patches in the four antenna units; at the same time, the direct-connected feeding structure and the coupled filter stripline feeding structure are simultaneously adopted in the antenna unit of the same frequency band, which realizes the antenna gain and broadband circular polarization in each frequency band, and improves the adaptability and flexibility of the antenna unit; by reasonably setting the operating frequency and feeding mode of the circularly polarized antenna unit in the antenna structure unit, signal crosstalk is avoided, and the effective integration of multi-band antennas is realized while maintaining the low profile characteristics.

The present invention discloses a balanced dual-frequency filter phase shifter, which loads two quarter-wavelength coupling lines at both ends of a pair of parallel microstrip lines, and loads an open-circuit microstrip line, a short-circuit microstrip line and a resistor at the terminal of the coupling line, so as to realize a balanced dual-frequency filter phase shifter with dual-frequency differential mode phase shifting, high frequency selectivity and broadband common mode suppression. Compared with the traditional filter phase shifter, the present invention can not only realize dual-frequency phase shifting, but also has good common mode suppression capability and high frequency selectivity.

The utility model relates to the technical field of optical fiber laser, specifically relates to a kind of based on phase continuous sweep frequency optical fiber laser, including shell, the inside one side of shell is fixedly installed with the multimode pump transmitter for emitting laser source, the output end of multimode pump transmitter is provided with phase modulator, the other end of phase modulator is provided with first fiber grating, the one side of first fiber grating away from phase modulator is connected with optical fiber body, the other end of optical fiber body is fixedly connected with second fiber grating, the other side of second fiber grating is fixedly connected with the multimode pump coupler of emission gain rear laser.Compared with prior art, the utility model, by being provided with first fiber grating and second fiber grating cooperate optical resonant cavity, and in optical resonant cavity outer wrapping heat pipe, the frequency of stable optical resonant cavity is ensured the stability of laser output frequency, and optical path length drift caused by heat effect can be reduced.

The invention discloses a copper nanomaterial electromagnetic shielding film and a preparation method and application thereof. The electromagnetic shielding film comprises a base material, and a material layer formed by mixing and stacking copper nanosheets and copper nanowires is loaded on the base material; the preparation method comprises the following steps: uniformly mixing and dispersing the copper nanosheets and the copper nanowires, carrying out suction filtration, and removing organic matters and oxide layers on the surfaces, so as to obtain the thin film with the electromagnetic shielding performance. And mixing copper nanowires and copper nanowires, and carrying out suction filtration to prepare the copper nanomaterial film. Due to the uniform grid arrangement of the copper nanosheets and the copper nanowires, the electromagnetic shielding film shows certain frequency selectivity, the working frequency band is 8.9-9.6 GHz, and the electromagnetic shielding film has good stability. The achievement is expected to be applied to electromagnetic shielding protection layers of aircrafts, glass windows of military or civil aircrafts, photoelectric cabins of helicopters and the like.