32results about How to "Good impedance matching" patented technology

A dual-band resonator with compact size, such as a resonant type dual-band antenna, which uses an anisotropic metamaterial is described. The artificial anisotropic medium is implemented by employing a composite right/left-handed transmission line. The dispersion relation and the antenna physical size only depend on the composition of the unit cell and the number of cells used. By engineering the characteristics of the unit cells to be different in two orthogonal directions, the corresponding propagation constants can be controlled, thus enabling dual-band antenna resonances. In addition, the antenna dimensions can be markedly minimized by maximally reducing the unit cell size. A dual-band antenna is also described which is designed for operation at frequencies for PCS/Bluetooth applications, and which has a physical size of 1/18λ₀× 1/18λ₀× 1/19λ₀, where λ₀ is the free space wavelength at 2.37 GHz.

The invention discloses a local discharge ultrahigh-frequency detection fractal antenna which comprises a dielectric layer and a conductor layer, wherein the conductor layer is laid on the upper surface of the dielectric layer and comprises a plurality of squiggly conductor segments which are connected end to end; the conductor segments are arranged according to the Hilbert fourth-order fractal principle to form a fourth-order radiating antenna element; the covering surface of the conductor layer on the dielectric layer is rectangular; the side length of the covering surface is the side length of the conductor layer; and a feed point is arranged on the conductor segment. The fractal antenna which has the advantages of good directivity, wide frequency bandwidth, low standing wave ratio and convenient impedance matching, can meet the requirement on the on-line monitoring and ultrahigh-frequency detection of the local discharge of a transformer; and in addition, the invention also discloses a preparation method of the local discharge ultrahigh-frequency detection fractal antenna.

This invention relates to a broadband single ridge waveguide slot array, resolving that the size, weight, loss, scanning angle and other aspects of existing waveguide slot array can not meet the special requirements. Its features are: the radiation waveguide has symmetric metal-single ridge on the center line of hemline and rectangular cross section, which connects with the feeding waveguide just below the bottom. The feeding waveguide has symmetric metal-single ridge on the hemline centerline. Coupling gap is set between radiation and feeding waveguide horizontally. The invention uses a single-ridge radiation waveguide to reduce the width of antenna, divides array into a number of sub-ones and feeds by power divider to improve the working bandwidth, uses ridge waveguide antenna to improve efficiency and reduce processing difficulties, uses coaxial connectors to easily realize impedance matching.

A signal transmission structure is provided. The structure mainly comprises at least a conductive via, at least a via land and a conductive wall. One end of the conductive via is connected to the via land. The conductive wall covers only a portion of the inner wall of a through hole in the core layer of a circuit substrate. The conductive wall has a semi-circular or a C-shaped structure. Therefore, when a signal passes the conductive via and the via land of the circuit substrate through the conductive wall in the interior of the via, because of a more continuous impedance between the via land and the conductive wall, signal reflection due to impedance mismatch along the signal transmission pathway can be reduced to enhance signal transmission quality.

The invention discloses a partial discharge ultrahigh-frequency detection Peano fractal antenna, wherein the partial discharge detection Peano fractal antenna comprises a dielectric layer and a conductor layer, wherein the conductor layer is laid on the upper surface of the dielectric layer; the conductor layer comprises a plurality of end-to-end bend conductor sections; the conductor sections are arranged according to the Peano three-stage fractal principle so as to form a three-stage radiation antenna element; the covering surface of the conductor layer on the dielectric layer is a rectangular surface; the side length of the covering surface is the side length of the conductor layer; and the conductor sections are provided with feeding points. The Peano fractal antenna provided by the invention has good direction property, is wide in frequency band, has small standing-wave ratio, is convenient for impedance match, and can meet the requirement of transformer partial discharge on-line monitoring ultrahigh-frequency detection.

The invention relates to a radiofrequency transmission system comprising: means of producing a complex digital signal quantised on N bits; means of transforming the complex digital signal into two complex digital signals with an identical and constant envelope that are phase-shifted with respect to one another; a digital processing pathway associated with each of the two complex digital signals with a constant envelope and comprising at least some filtering means of the sigma-delta type for quantising on M bits signals travelling in the processing pathway, M being less than N; digital-to-analogue conversion means for converting the outputs of the digital processing pathways into analogue signals; means of selectively filtering (of the bandpass type) the analogue signals in a predetermined transmission frequency band; means of amplifying the filtered analogue signals; and means of recombining the amplified analogue signals.

The invention discloses a ceramic full-sealed surface package of microwave devices. A ceramic frame of the package is arranged on a substrate, wherein the substrate can serve as a circuit which is grounded and also have the heat dissipation function. The cavity in the ceramic frame is used for containing MMICs or other microwave devices. The substrate is slightly smaller than the ceramic frame so that metal pins can be welded to the bottom of the ceramic frame, and the metal pins and the substrate are located in the same plane. Radio-frequency and direct current conductive wires on the first layer of ceramic of the package are connected with devices inside the package and connected to the outside of the package through via holes. The package can also not be provided with the pins additionally, and bonding pads of the ceramic frame are directly welded to a printed circuit board. A layer of metal sealing ring is deposited on the upper side of the second layer of ceramic to achieve full sealing. The sealing ring is grounded through a conductive via hole penetrating through the ceramic. The full-sealed package can eliminate resonance in a very wide frequency band and reduce the parasitic effect to the minimum, thereby achieving good broadband performance. Meanwhile, the package has the excellent heat dissipation function and therefore can be widely applied to a great number of high-power devices.

The invention discloses an X-frequency-range extra-low inter-modulation frequency converter device of a measurement and control system. The X-frequency-range extra-low inter-modulation frequency converter device comprises an X-frequency-range isolator (1), an X-frequency-range filter (2), an X-frequency-range mixer (3), a first local oscillator isolator (4), a first intermediate-frequency low pass filter (5), a first intermediate-frequency band pass filter (6), a first intermediate-frequency amplifier (7), a second mixer (8), a second local oscillator isolator (9), a second intermediate-frequency low pass filter (10), a second intermediate-frequency band pass filter (11), a programmable attenuator (12) and a second intermediate-frequency amplifier (13). The X-frequency-range extra-low inter-modulation frequency converter device has the advantages of being stable in gain phase and low in inter-modulation signal and can be applied to a signal receiving chain with extra-low signal to noise ratio of a deep space measurement and control system.

The invention discloses a small coplanar waveguide fed broadband antenna which comprises a dielectric substrate of rectangular structure, wherein the dielectric substrate is 1.6mm thick, a radiation patch, a feed network and earth plates are arranged on one side of the dielectric substrate respectively, three-level staircase structures integrated with the radiation patch are symmetrically disposed on the left and right sides of the radiation patch, the lower end of the radiation patch is connected with the feed network, the earth plate are symmetrically disposed on the left and right sides of the feed network, and a tuning stub which is integrated with the earth plate is arranged on the earth plate in a corresponding mode. The working band of the small coplanar waveguide fed broadband antenna covers 8.6 to 12.1 GHz, and the broadband antenna achieves good impedance matching within effective bandwidths. In addition, the broadband antenna is simple in structure, small in size, easy to produce, suitable for wireless communication systems, and wide in application prospect.

The invention discloses a BVD model-based BAW filter design method and device and equipment. The method comprises the following steps of: constructing an original equivalent circuit model, consistingof a plurality of serial and/or parallel harmonic oscillators, of a BAW filter according to a BVD circuit model, and setting an optimum parameter according to optimization characteristics of the BAW filter; extracting a circuit model parameter of a single harmonic oscillator; constructing an initial layout of the BAW filter according to the extracted circuit model parameter of the single harmonicoscillator; optimizing the initial layout and extracting the circuit model parameter of the BAW filter and the circuit model parameter of the single harmonic oscillator so as to obtain an optimizationparameter; and if a difference value between the optimum parameter and the optimization parameter exceeds a preset range, continuing to adjust the optimized initial layout until the difference valueaccords with the preset range. According to the method and device and the equipment, correct equivalence between physical field simulation and the circuit models in BAW filter design is realized and more correct results are provided for the production of filters.

A multiband antenna with the broadband function has a radiator, a feed cable, a first extension conductor, and a second extension conductor. The radiator has a microwave substrate, a coupling conductor, a first conductor, a second conductor, a third conductor, and a connecting conductor. The coupling conductor is connected with a positive signal wire of the feed cable. The third conductor is connected with a negative signal of the feed cable for transmitting electrical signals. The radiator generates the multiband mode of the antenna. By connecting the first extension conductor and the second extension conductor with the radiator, the surface current distribution and impedance variation of the antenna can be effectively adjusted to achieve the broadband effect.

The invention discloses a multi-hole fuzz-ball-shaped NiFe/C/Na2MoO4 composite wave absorbing material. The wave absorbing material comprises multi-hole fuzz-ball-shaped Na2MoO4 and NiFe/C nanometer cubes. The NiFe/C nanometer cubes are uniformly distributed on the surface of the multi-hole fuzz-ball-shaped Na2MoO4. According to the method, the fuzz-ball-shaped Na2MoO4 deriving from Mo2CTx is usedas a matrix, the NiFe/C nanometer cubes deriving from NiFe-MOF are used as load layers, the obtained composite material solves the problems that a wave absorbing material deriving from MXene is single in morphology and the wave absorbing ability is insufficient, the good impedance match and the efficient electromagnetism damping ability are obtained, thus the wave absorbing characteristics of thinness, lightness, width, strength and the like within the 2-18 GHz frequency range are achieved, and the material is an ideal selection of a microwave absorbing material.

The invention discloses a small-loop antenna for ultra-high-frequency detection of partial-discharge. The small-loop antenna comprises a dielectric layer, a conductor layer, a matching resistor and a feed terminal, wherein conductors are uniformly wound on the surface of a magnetic core; and the feed terminal is in parallel connection with the matching resistor and is used for feeding in a coaxial feeding manner. The small-loop antenna disclosed by the invention has the advantages of good directivity, wide frequency band, small standing-wave ratio and convenience in impedance matching, thus being capable of meeting the requirements on the online-monitoring ultra-high-frequency detection of the partial discharge in a power transformer.

The invention relates to the field of radio frequency identification (RFID) and provides a plane broadband passive electronic tag. The tag comprises an antenna, a chip and a substrate, wherein the substrate is rectangular and is used for containing the antenna and the chip; the antenna is matched with the chip; the antenna comprises a rectangular radiation surface and a short-circuit ring; the short-circuit ring is located at the bottom of the substrate; the rectangular radiation surface comprises a rectangular radiation surface obtained by removing a rectangular shape of the short-circuit ring; the chip is located at the place, close to the edge of the substrate, on the short-circuit ring. The plane broadband passive electronic tag which is applied to the surface of an object with a high dielectric constant has a farther reading distance and a wide bandwidth, and has strong applicability; meanwhile, the chip is located at the place close to the edge of the substrate so that information concluding codes, characters and patterns and the like can be conveniently printed on the back surface of the tag and the chip is prevented from being crushed in a printing process; the tag can be conveniently applied to various fields.

The invention relates to a high-gain metamaterial antenna, comprising a dielectric substrate, a metal structure, a feeder and a reference ground, wherein the metal structure, the feeder and the reference ground are all arranged on the dielectric substrate; the feeder is coupled with the metal structure; the reference ground comprises a first reference ground unit and a second reference ground unit located on the two opposite surfaces of the dielectric substrate; and the first reference ground unit enables one end of the feeder to be formed into a microstrip line. The high-gain metamaterial antenna provided by the invention obtains the desire effective dielectric constant and magnetic conductivity distribution by precisely controlling the topological form of the metal structure and rationally arranging the microstrip line; therefore, the antenna is capable of realizing good impedance matching in the working frequency range, completing energy conversion at high efficiency and obtaining ideal radiation pattern; and the antenna is small in occupied volume, low in requirement for the environment, high in gain, wide in application range, and capable of serving as the built-in antenna for various electronic products.

The invention relates to the technical field of preparation of wave-absorbing materials, particularly to a preparation method of wave-absorbing foam for absorbing low-frequency electromagnetic waves.The preparation method comprises the following steps: compounding flexible polyurethane foam with obtained reduced graphene oxide/carbonyl iron foam or hydroxylated carbon nanotube/carbonyl iron foamslurry through an impregnation process, and further carrying out thermal reduction to obtain an upper matching absorption layer; and compounding flexible polyurethane foam with aqueous carbon nanotubeslurry or low-defect graphene through an impregnation process to obtain a lower reflection absorption layer, and bonding the lower reflection absorption layer with the upper matching absorption layerto the form final wave-absorbing foam. The influence of process parameters on the structure and performance of the wave-absorbing foam is studied in the invention. On the premise that low thickness and broadband absorption of the wave-absorbing foam are maintained, the problem that the wave-absorbing foam is not high in absorption performance in an L waveband (1-2 GHz) is mainly solved.

The invention is applicable to the technical field of wireless communication, and provides an impedance matching structure and a radio frequency device, the impedance matching structure is formed on acircuit board with a radio frequency link, and the impedance matching structure comprises a signal bonding pad used for connecting a signal line of a coaxial guided wave structure; the first matchingpart is connected with the signal bonding pad, and the first matching part is in a gradual change shape; the open circuit branch knot comprises a second matching part, and the second matching part isconnected to one end, deviating from the first matching part, of the signal bonding pad and is gradually changed; the at least one grounding bonding pad is used for being connected with a grounding layer of the coaxial guided wave structure; through cooperation of the first matching part and the open circuit branch knot, impedance matching of connection between the coaxial guided wave structure and the radio frequency link is better, signal reflection is reduced, and a working frequency band window value is improved. Moreover, the impedance matching structure is formed on the circuit board, so that the complexity and the cost of manufacturing and assembling can be reduced.

The invention discloses a passive ultrahigh-frequency RFID tag for temperature alarming. The tag comprises a tag chip and a tag antenna connected with the tag chip, wherein the tag chip comprises a radio-frequency analog front-end unit, a logic control unit and a storage unit, which are connected in sequence. The radio-frequency analog front-end unit is connected with a power supply module, an impedance matching network module, a demodulation module and a modulation module of the logic control unit. The impedance matching network module comprises a first capacitor, a second capacitor, a first PMOS switch transistor, a second PMOS switch transistor and a barium titanate thermistor. The first capacitor and the second capacitor are connected in parallel between the tag antenna and the ground; and the gates of the first PMOS switch transistor and the second PMOS switch transistor are connected in series with the barium titanate thermistor and then are connected to the power supply module, the drains of the first PMOS switch transistor and the second PMOS switch transistor are connected to the signal feed-in end of the tag antenna, and the sources of the first PMOS switch transistor and the second PMOS switch transistor are grounded.

The present invention provides a horizontal polarized broadband biconical omni-directional antenna. The horizontal polarized broadband biconical omni-directional antenna comprises a biconical omni-directional antenna, a foam installation support and multiple layers of metal gate polarizers formed by a plurality of polarized grating pieces. The polarized grating pieces in the multiple layers of metal gate polarizers are metal gates with a certain deflection angle; the foam installation support is cylindrical and is sleeved at the side surface of the biconical omni-directional antenna to form acircle polarized grating piece installation base, and the polarized grating pieces are installed on the foam installation support in order in a layered winding mode; and foam strips are installed between the polarized grating piece. The horizontal polarized broadband biconical omni-directional antenna does not need arraying or a complex feed network, has broadband and horizontal polarization.

The invention provides a low-temperature coupler and an application method thereof. The low-temperature coupler comprises a cavity, wherein a cover covers an opening of the cavity, a PCB is arranged in the cavity and comprises an AC part and a DC part, the AC part is provided with an AC functional module, an input port of the AC part inputs a radio frequency signal and a pulse signal, the DC partis provided with a medium-frequency functional module and a low-frequency pulse functional module which are connected with each other, and the medium-frequency functional module and the low-frequencypulse functional module are provided with devices used for preventing signal interference, and a signal of the AC part and a signal of the DC part output through the same output port. The low-temperature coupler can be compatible with a 4-8GHz continuous microwave signal and also can be compatible with an arbitrary wave pulse signal with lowest 10MHz, and serious deformation of the signal is prevented.

The invention provides a low-profile broadband dual-mode compression dipole antenna, which comprises a radiation unit composed of a first dielectric substrate and a dipole antenna, wherein the dipoleantenna is printed on the bottom surface of the first dielectric substrate; a feed balun which is composed of a second dielectric substrate, a first metal ground and an L-shaped metal strip, wherein the first metal ground and the L-shaped metal strip are printed on the two opposite faces of the second dielectric substrate respectively; and an artificial magnetic conductor, wherein the radiation unit is arranged on the artificial magnetic conductor through the feed balun. According to the low-profile broadband dual-mode compression dipole antenna, the feed Balun is used for feeding, so that theinput resistance is obviously reduced, the technical problems that the real part impedance of a dipole of a secondary mode is too high and is difficult to match are solved, and good impedance matching is realized.

The invention discloses an ultra-wideband monopole patch antenna for partial discharge detection, and the specific structure is that a monopole patch is arranged at the middle of the front surface of a square FR4 substrate, wherein one side of the monopole patch is connected with a rectangular feeder line, and the other side of the feeder line extends to the edge of the FR4 substrate and is connected with an SMA interface arranged at the edge of the FR4 substrate; a rectangular metal floor is arranged at one side, close to the SMA interface, of the back surface of the FR4 substrate; an inner core of the SMA interface is connected with the monopole patch, and a grounding electrode is connected with the floor. The antenna has the advantages that impedance matching is easy to realize, the process is simple, processing and production are easy, the antenna is easy to connect with mobile detection equipment by using an SMA interface for feeding, and the antenna can be more widely applied to actual production; the antenna can achieve the bandwidth of 0.5 GHz-1.57 GHz; more importantly, compared with other antennas with the same working bandwidth, the antenna is much smaller, thereby facilitating the practical application.

The invention discloses a broadband adjustable terahertz wave absorber based on graphene. The broadband adjustable terahertz wave absorber comprises a top layer, a first dielectric layer, a middle layer, a second dielectric layer and a bottom layer substrate which are sequentially arranged from top to bottom. The top layer and the middle layer are both graphene layers, wherein the absorption peaks of incident waves are crossed and overlapped when the top layer and the middle layer reach resonance; the chemical potential of the top layer is regulated and controlled through a bias voltage Vg between the top layer and the bottom layer substrate, and the chemical potential of the middle layer is regulated and controlled through a bias voltage Vs between the middle layer and the bottom layer substrate. According to the invention, the top layer and the middle layer are arranged and are both graphene layers, so that good impedance matching is realized; absorption peaks of incident waves are crossed and overlapped when the top layer and the middle layer achieve resonance, so that the working bandwidth is effectively widened; the chemical potential of the graphene layer is dynamically regulated and controlled through bias voltage, and the dynamic regulation effect of the wave absorbing amplitude of the wave absorber is achieved; the broadband adjustable terahertz wave absorber is simple in structure, small in size, perfect in absorption effect and good in flexibility.

The invention discloses a passive anti-metal label antenna which is applied to an electronic number plate and is based on an RFID (Radio Frequency Identification) technology. The passive anti-metal label antenna comprises an inverse T-shaped gap, an RFID chip and a plane dielectric substrate of which shape size is the same to that of a number plate. The inverse T-shaped gap is located on the edge of the number plate and is opened. Two poles of the RFID chip stretch across a centre of a vertical gap. The plane dielectric substrate is pasted on the back of the number plate. The passive anti-metal label antenna is simple in structure and low in production cost. When the passive anti-metal label antenna works on a metal surface, the passive anti-metal label antenna has anti-metal performance and is wide in beam, high in gain and remote in reading distance. The passive anti-metal label antenna is very suitable for an application scene of the electronic number plate.

The invention discloses an automatic simulation loop impedance matching detection method, and the method comprises the following steps: automatically carrying out the impedance matching between a user loop transmission line and a signal source through employing an impedance automatic matching system which is formed through the interaction of a DSP processing system based on a CPU and an SLIC chip, an optimal matching impedance signal is obtained; and the optimally matched impedance value is set in the SLIC, so that the quality is optimal when the signal is transmitted to the stored program control exchange. According to the invention, the manual test intensity can be reduced, the test time can be shortened, and the matching accuracy can be improved, so that the communication quality is improved, the tone quality level of a call is improved, the noise is reduced, and the communication quality and the communication success rate of data terminals including fax, pos machines and other communication equipment are improved.

The invention discloses a planar dipole binary parasitic array antenna, which is characterized in that parasitic metal units are additionally arranged on two sides of a planar dipole antenna, and the lengths and the positions of the metal units are properly adjusted, so that the antenna gain can be greatly increased, and the problems of large antenna size and complex antenna structure are solved. Besides, the planar dipole binary parasitic array is only provided with one feed port, the impedance matching degree of the antenna can be improved by adjusting the length and the position of the parasitic strip metal units, the gain of the antenna is improved, and the planar dipole binary parasitic array is simple in structure, easy to process, low in cost, high in precision and suitable for mass production, and can be produced by using a PCB. The technical problem that a dipole array antenna feed network in the prior art is complex in design structure is solved.

A receiver for an N-wire digital interface, where N is any integer exceeding two, has N input terminals, a common node and N detection stages. Each of the N detection stages has a resistive element coupled between the common node and a respective one of the N input terminals, and a comparator having a first input coupled to the respective one of the N input terminals and a second input coupled to the common node.

The invention relates to a coaxial series-parallel feed omnidirectional biconical dipole sleeve antenna, which belongs to the technical direction of antenna microwaves, consists of a biconical dipole sleeve antenna unit and a coaxial series-parallel feed network, and mainly comprises a biconical dipole, a metal sleeve and the coaxial series-parallel feed network, wherein the radiating body gradient structure of the biconical dipole antenna unit can enable the radiating body gradient structure to obtain better impedance matching with a free space; the coaxial metal sleeve outside the radiating body can further broaden the working bandwidth of the antenna unit; and the biconical dipole antenna units are in omnidirectional radiation in the horizontal direction, and a coaxial series-parallel feed network is adopted to form an array in the vertical direction, so that the high-gain performance of the antenna is achieved. The coaxial series-parallel feed network is composed of a linear gradient impedance conversion section and a two-stage coaxial power divider. The coaxial series-parallel feed network has no influence on the direction of a vertical plane directional diagram of the antenna, is simple in structure and easy to realize, and can be used as a structural support of an omnidirectional antenna.

The invention discloses a miniaturized omnidirectional UHF-RFID tag antenna. The miniaturized omnidirectional UHF-RFID tag antenna comprises an antenna chip, a radiating antenna and a dielectric substrate. The radiation antenna comprises an antenna arm, an impedance matching network and radiation patches; the antenna arm is an open outer loop; the radiation patches are arranged in a central symmetry manner by taking the center of the dielectric substrate as a reference point; the overall outline of the impedance matching network is ''E''-shaped; the antenna chip is electrically connected with the conical impedance matching network to form a closed inner loop; the open type outer ring loop forms a single-sided bent dipole antenna; the two radiation patches form a rectangular patch antenna for capacitive top loading; and the dielectric substrate, the closed inner loop, the bent dipole antenna and the rectangular patch antenna cooperate with each other so that the size of the radiation antenna is reduced, the length of the antenna is shortened, and the working bandwidth, gain and omnidirectional performance of the antenna are improved. The invention also discloses a production method of the antenna.