47results about How to "Improve standing wave" patented technology

The invention discloses a low profile low RCS ultra wide band wide-angle scanning strong mutual coupling phased array antenna based on a polarization conversion metamaterial. The antenna can achieve two-dimensional wide-angle scanning in four octaves with a profile height of only 0.267 times of the high-frequency wavelength, the low profile requirement of the antenna is met, and meanwhile the RCS of the antenna is effectively reduced under the premise that the new polarization conversion material loaded does not affect the radiation performance of the antenna. The whole antenna structure mainly comprises a dielectric substrate (1), an interdigital dipole unit (2) printed on the dielectric substrate; rectangular patches (3) on both sides of the dipole; a strip line Balun (4) under the dielectric substrate of the antenna for connecting an antenna and a floor; a dielectric layer (6) below of the balun and having a metal floor layer (5) on the upper surface; a polarization conversion metamaterial (7) which is loaded on the metal floor; (8) a centimeter network on the lower surface of the dielectric layer; and a microwave coaxial cable (9) fed to the centimeter network.

The invention relates to a millimeter-wave-based microstrip-coaxial transformational structure. Special dual-air-cavity-transitional design is adopted, so that high performance requirement on microwave signal transmission is satisfied; signal transmission is carried out by adopting a dual-air-cavity-transitional way; an annular matched bonding pad is adopted at the input end of the microstrip, so that high microstrip-coaxial matching is realized, and effective signal transmission is ensured; and two air cavities are introduced at the input end and the output end of a coaxial body for transition, so that the port standing wave is improved, and the transmission efficiency is improved.

A central symmetric horizontally-polarized broadband omnibearing array antenna comprises a round dielectric plate, wherein a power division feed network is arranged on a surface of the round dielectric plate, a common disc metal ground is arranged on the other surface of the round dielectric plate and outwards extends to form a circular metal foil, the circular metal foil is uniformly partitioned into four circular arc printing dipoles by a first radial gap, a second radial gap, a third radial gap and a fourth radial gap which are arranged on the circular metal foil, a radial intermediate gap is formed on each circular arc printing dipole and arranged on a radial symmetric central line of the circular arc printing dipole, a radial rectangular coupling branch is arranged in each radial gap, arc gaps are connected to the inner side ends of the radial gaps, all arc gaps are concylic by taking the center of the common disc metal ground as a circle center, an arc guide branch is arranged on the outer side of each radial gap, and all arc guide branches are arranged on a circumference taking the center of the common disc metal ground as the circle center.

The invention belongs to the technical field of communication and navigation and in particular relates to a multi-frequency navigation terminal antenna. A top-layer feeding point is arranged at the center of a first-layer micro-strip patch; a central feeding hole is vertically formed in the top-layer feeding point; a first feeding point is arranged at a second-layer micro-strip patch; a first feeding hole is vertically formed in the first feeding point; a second feeding point is arranged at a third-layer micro-strip patch; a second feeding hole is vertically formed in the second feeding point; a third feeding point is arranged at a fourth-layer micro-strip patch. The antenna also comprises first short circuit metallized via holes and second short circuit metallized via holes which are used for eliminating coupling influence of feeding probes in all the feeding holes. The multi-frequency navigation terminal antenna disclosed by the invention can cover L band and S band of first-generation Beidou, B1 band and B3 band of second-generation Beidou and L1 band of a GPS (Global Positioning System); the demands on minimization and lightness of antenna size are met while good impedance bandwidth, axial ratio bandwidth and high-gain performance can be guaranteed.

The invention discloses a feedback network which comprises a first energy coupling part, a phase shift wire and a second energy coupling part. The first energy coupling part is arranged on a first feed line of an array antenna or is arranged in the preset range of a first antenna unit of the array antenna and is used for carrying out coupling on signals sent by the first antenna unit, and first coupling signals are obtained. The phase shift wire is connected with the first energy coupling part and is used for receiving the first coupling signals, and the first coupling signals are subjected to phase adjusting and then are output. The second energy coupling part is arranged on a second feed line of the array antenna or is arranged in the preset range of a second antenna unit of the array antenna and is used for carrying out coupling on the first coupling signals after phase adjusting, and second coupling signals are obtained. The second coupling signals are sent to the second antenna unit through the second feed line to offset reflecting signals received by the second antenna unit. The invention further discloses the array antenna. Array antenna standing waves can be improved, and the bandwidth of the array antenna is improved.

The invention discloses an ultralow-profile low-scattering ultra-wideband phased-array antenna based on electromagnetic metamaterial loading, which realizes E-plane + / -70-degree scanning and H-plane + / -60-degree scanning in a 6-18GHz broadband, and the profile height of the ultralow-profile low-scattering ultra-wideband phased-array antenna is only 0.28 high-frequency (18GHz) wavelength. The loaded electromagnetic metamaterial is composed of a split ring periodic structure, an I-shaped resistive patch, an intersecting long-strip periodic structure and a plurality of wide-angle impedance matching layers, and through the integrated design of the electromagnetic metamaterial and the phased-array antenna, the phased-array antenna has the ultra-wide-band and ultra-wide-angle scanning characteristic and meanwhile has the remarkably low profile height. In addition, the cross polarization RCS of the phased-array antenna is remarkably reduced within the full-frequency range of the working frequency of the phased-array antenna, and meanwhile, the radiation efficiency of the phased-array antenna is kept above 95%.

The invention discloses an on-chip integrated broadband linearizer based on a variable capacitor, and belongs to the technical field of microwave and millimeter wave monolithic circuits. A linearizedcircuit control module is used for controlling a direct-current voltage drive provided for a reflective pre-distortion signal generator and a cold-mode pHEMT transistor compensation correction circuit, so as to adjust the size of the generated linearized signal. Then, a reflective pre-distortion signal generator and a cold mode pHEMT transistor compensation correction circuit are combined; the pre-distortion signals are generated and compensated, pre-distortion linearized signals are finally generated to counteract nonlinearity of the power amplifier, and the reflective pre-distortion signal generator and the cold mode pHEMT transistor compensation correction circuit are matched with a low-loss matching module to further reduce insertion loss. According to the broadband linearizer, the problem that a traditional linearizer cannot be applied to a broadband is solved, and the bandwidth is better broadened. The filter has the characteristics of low insertion loss, wide application bandwidth, compact structure and remarkable linearization improvement.

The invention provides an inverting power synthesizer, which belongs to the technical field of radio frequency and microwave power synthesis design. The synthesizer comprises a first dielectric substrate with a first microstrip line and a second dielectric substrate with a second microstrip line. Two dielectric substrates are separated by a ground plate. The output end of each microstrip line is connected with a waveguide cavity. A first ridge plate and a second ridge plate are symmetrically designed in the waveguide cavity. The first ridge plate and the second ridge plate form a continuouslynarrowing opening size when extending from one end of the waveguide cavity to the other end, and ridge waveguide is formed and impedance transformation is realized. The output end of each microstrip line is connected with a power dividing microstrip line and a load resistor to realize isolation between sub-ports. The synthesizer provided by the invention realizes reverse phase power division and has better isolation performance and port standing wave performance.

The invention provides a CSRR structure-based ultra-wideband electrical tunable equalizer. A stepped impedance type microstrip is adopted as a main transmission line, notch units are connected betweenthe main transmission line and bias loops, and each notch unit comprises a load absorption resistor, a CSRR resonance unit and a variable capacitance diode which are connected in series, wherein a capacitance value of the notch unit is adjusted by controlling a reverse voltage applied to the variable capacitance diode to adjust the center frequency and the equilibrium quantity of the notch unit.The CSRR structure-based ultra-wideband electrical tunable equalizer is low in path loss, can achieve wider-range power equilibrium and can precisely control frequency points and frequency bands whichneed be equalized.

The invention relates to an ultrasonic cleaning machine for cleaning residues left after laser engraving of a plastic casing of a mobile phone. The ultrasonic cleaning machine comprises a cleaning machine casing, a cleaning tank, a side piezoelectric transducer, a bottom piezoelectric transducer, a left-right direction ultrasonic generator, a front-back direction ultrasonic generator, an up-down direction ultrasonic generator, a liquid storage tank, a circulating pump, a filter, a heating pipe, a condensing pipe and a temperature controller; the cleaning tank is mounted and fixed in the cleaning machine casing; the cleaning tank comprises a bottom plate and four side plates, and the bottom plate is quadrangular, is not parallel to the horizontal plane and is inclined; the four side platesextend upward from the four edges of the bottom plate, and are not vertical but inclined; and the left-right direction ultrasonic generator and the front-back direction ultrasonic generator are connected with and control the side piezoelectric transducer, and the up-down direction ultrasonic generator is connected with and control the bottom piezoelectric transducer. According to the ultrasonic cleaning machine provided by the invention, ultrasonic sound pressure distribution is uniform during cleaning, standing waves are improved, the solution temperature is easy to control, and the cleaningeffect is good.

The invention relates to a planar four-channel power combining amplifier, belonging to the technical field of communication, which solves the problems of limited adjustable range of amplitude and phase of the existing power combining amplifier and poor combining efficiency. The planar four-channel power combining amplifier comprises a power distributing module, a phase adjusting module, a power amplifying module and a power combining module which are connected in turn. The power distribution module is used for performing power distribution processing on the input signal according to the presetpower distribution demand to obtain four-channel power distribution signal. A phase adjusting module performs phase adjusting processing on four signals after power distribution. The power amplifyingmodule performs power amplifying processing on four signals after phase adjusting, and a power combining module performs power combining processing on four signals after power amplifying, so as to obtain the final signal output satisfying the preset power demand. The invention has the advantages of simple structure, small volume, high system stability and high output power, and the output power can reach more than 10W.

The present invention provides a vertically polarized antenna which comprises three layers of the dielectric plates which are a first layer, a second layer and a third layer. The right end of each layer of dielectric plate has a section of L area extending leftward from the right boundary of the dielectric plate, a stepped substrate integrated waveguide structure whose L area height is higher than that of the left side of the L area is formed by the whole second layer, a first layer L area and a third layer L area together. The length of the L area is L. The vertically polarized antenna comprises the stepped substrate integrated waveguide structure, through using the step transition technology is employed at an E plane, for E plane discontinuities, the transition of the E plane is carried out directly, the antenna standing wave is greatly improved, the efficiency is high, the size is only changed for several millimeters, according to the E plane transition structure, the antenna E plane directivity can be improved, at the same time through laying electromagnetic band gap structures at upper and lower surfaces, in the condition of not enlarging the antenna size, the backward radiation is greatly inhibited, and the antenna E plane directivity is further improved.

The invention discloses a coaxial-to-microstrip connector suitable for a cavity filter and an assembling method, and relates to the connector technical filed. The coaxial-to-microstrip connector comprises a substrate capable of being simultaneously connected with the cavity filter and a microwave circuit, a microstrip cavity is formed at one side of the substrate, and an air transition cavity penetrating to the other side of the substrate is formed at one end, far away from an opening, in the microstrip cavity. By using the coaxial-to-microstrip connector, the impedance matching characteristicof the cavity filter at the coaxial-to-microstrip position in a microwave integrated circuit is ensured, the debugging workload of the debugging personnel is greatly reduced, at the same time, the consistency of products is ensured, and the working efficiency is improved.

The invention discloses a high-gain automobile millimeter wave radar array antenna. The high-gain automobile millimeter wave radar array antenna comprises a millimeter wave radar chip interface, a first receiving linear array antenna, a second receiving linear array antenna, a third receiving linear array antenna, a fourth receiving linear array antenna, a transceiving isolation linear array antenna, a first transmitting linear array antenna, a second transmitting linear array antenna, a third transmitting linear array antenna and a fourth transmitting linear array antenna. The core architecture of the high-gain automobile millimeter wave radar array antenna adopts a four-transmitting and four-receiving antenna array mode, adopts eight angle-feed array elements with same phase and same amplitude as a transmitting unit, and combines a combination method of tangential circular polarization and surface slotting of a symmetrical structure to reasonably suppress the sidelobe level of the antenna, control the size and the position of an antenna parasitic unit, optimize the radiation characteristic of the antenna and improve the impedance matching characteristic. The high-gain automobilemillimeter wave radar array antenna has the advantages of high precision, high response speed, high resolution, high stability, miniaturization and low cost, and can be used for medium-distance and long-distance detection millimeter wave radar system schemes.

The invention discloses a dual-polarized antenna and an oscillator thereof. The oscillator comprises: two groups of radiation units of which the polarization directions are mutually orthogonal, a balanced feeding assembly is used for feeding the radiation units, and a coupling ring sleeved on the balanced feeding assembly. A gap is formed between the inner wall of the coupling ring and the outer wall of the balanced feeding assembly, and the coupling ring can be in electromagnetic induction connection with the radiation units. The oscillator can improve the standing wave of the radiation units, improves the working bandwidth, and is good in electrical performance. Therefore, the electrical performance of a dual-polarized antenna adopting the oscillator is good.

The invention discloses a high-power 100-watt 11dB attenuation plate with an aluminum nitride ceramic substrate. The high-power 100-watt 11dB attenuation plate comprises the aluminum nitride ceramic substrate which is 5.7 mm wide, 8.9 mm long and 1 mm thick, a silver paste back conducting layer is printed on the back face of the aluminum nitride ceramic substrate, a silver paste wire and five black resistors are printed on the front face of the aluminum nitride ceramic substrate, the silver paste wire is connected with the resistors to form a TT type attenuation circuit, the five black resistors are respectively and correspondingly printed with a glass protecting film, and the five glass protecting films and the wire are printed with two protecting films. The high-precision thick film printing technology is adopted for the silver paste back conducting layer, the silver paste wire, the five black resistors, the glass protecting films and the two protecting films. According to the design thought of the attenuation plate, the circuit structure of an input end is optimized, standing waves of the input end are improved, and meanwhile a high-precision attenuation value is obtained by accurately modifying resistance values. The high-power 100-watt 11dB attenuation plate with the aluminum nitride ceramic substrate has various excellent indexes and meets the use requirements of a current 4G network.

The invention discloses an array antenna for an automobile radar sensor, and the array antenna comprises a millimeter wave receiving and transmitting chip bonding pad, a first receiving linear antennaarray, a second receiving linear antenna array, a third receiving linear antenna array, a fourth receiving linear antenna array, a first transmitting linear antenna array, a second transmitting linear antenna array, and a third transmitting linear antenna array. The core architecture of the array antenna adopts a three-transmitting four-receiving antenna array mode, and adopts ten in-phase non-equal amplitude angle feed array elements as a basic unit structure to control the size and position of an antenna parasitic unit, reasonably suppress the sidelobe level of the antenna and optimize theradiation characteristics of the antenna. The impedance matching characteristic is improved by combining a combination method of tangential circular polarization and surface slotting of a symmetricalstructure . According to the scheme, high precision, high response speed and high resolution can be achieved, and a millimeter wave radar system scheme for medium-distance and long-distance detectioncan be achieved.

The invention belongs to the technical field of dispersion compensation, in particular to a phase dispersion compensation device for a waveguide array antenna feeding network. The present invention includes a dispersion compensation unit arranged on the output arm of the straight-through port of the waveguide branch bridge. The dispersion compensation unit includes a first ladder impedance transformation section, a dispersion compensation transformation section, and a second ladder connected to the output arm of the straight-through port in sequence. The impedance transformation section and the signal output transformation section, the step impedance transformation section is used to reduce the transmission line impedance jump and mismatch caused by the sudden change of the waveguide width, effectively improving the standing wave of the port, the step impedance transformation section and dispersion compensation The transformation segments are all involved in the compensation of the dispersion phase. The invention changes the phase velocity of the electromagnetic wave in the waveguide, and cooperates with the corresponding waveguide length to well compensate the influence of the dispersion effect on the feeding network.

The invention provides a patch antenna. The patch antenna at least comprises a feed structure, a supporting piece and a near-field coupling piece, the supporting piece is fixed on the feed structure,and the near-field coupling piece is fixed on the supporting piece. The edge of the near-field coupling piece is provided with at least one pair of symmetrical slots. The invention further provides anantenna array with at least one patch antenna. Therefore, the antenna isolation can be obviously improved, the S parameter of the patch antenna in the array is improved, and the directional diagram index is not influenced.

The invention discloses a wideband intermatch power amplifier. The wideband intermatch power amplifier comprises an input port, Lange couplers, bandpass filtering impedance transforming circuits, stabilizing networks, power chips and an output port, wherein the input port is connected with a first port of the first Lange coupler; a third port and a fourth port of the first Lange coupler are respectively connected with inputs of the first bandpass filtering impedance transforming circuit and the third bandpass filtering impedance transforming circuit; the input terminal of the first bandpass filtering impedance transforming circuit is connected with the input of the first stabilizing network; the output of the first stabilizing network is connected with a first terminal of the first power chip; a second terminal of the first power chip is connected with the input of the third bandpass filtering impedance transforming circuit; the output of the third bandpass filtering impedance transforming circuit is connected with a first port of the second Lange coupler. The wideband intermatch power amplifier can draw both wide band and high gain indicators into consideration, utilizes the Lange couplers for power synthesis, improves the input and output standing waves and facilitates front-and-back-stage multi-tube cascade application.

The invention relates to the radio frequency microwave field, in particular to a waveguide magic T structure. The waveguide magic T structure comprises a waveguide cavity; a metal separator which divides a part of the waveguide cavity into upper and lower reduced waveguides with a metal groove formed therein; a microstrip circuit cavity located on one side of the waveguide cavity and provided withwaveguide sidewall openings at positions adapted to the waveguide cavity; a dielectric substrate of a microstrip circuit parallel to the metal separator, a microstrip line being arranged on the frontside, and a groove line being arranged on the reverse side and connected with the metal groove; a load resistor connected to microstrip line. The waveguide magic T structure of the invention improvesthe isolation of the input port and the standing wave of the port of a synthesizer compared with the waveguide T-joint, facilitates the connection between modules and the system integration, and reduces the instability of the system caused by the unbalance between the paths or even the damage of one path during the integration of the multiple paths of the system. In addition, compared with the conventional waveguide magic T, the waveguide magic T structure realizes miniaturization by adopting a folded waveguide.

The invention discloses a millimeter wave radar array antenna which a one-to-twelve input power division matching network and first to twelfth angular feeder arrays. The core architecture of the invention adopts an in-phase non-equal amplitude angle feed ten-element structure, and a corner cut circular polarization method of a symmetrical structure and a combination method of surface slotting arecombined to control the size and position of an antenna parasitic unit, the antenna sidelobe level is reasonably suppressed and the radiation characteristics of the antenna is optimized. Meanwhile, amultilayer substrate design structure and a TSV interconnection technology are utilized, the signal interference of an antenna feeder structure on an antenna resonance unit is reasonably avoided, thedielectric loss is reduced, the radar detection sensitivity and overall detection performance are improved, and circuit integration and equipment miniaturization are facilitated.

The invention discloses an aluminum nitride ceramic substrate 100 W-6 dB attenuation slice. The attenuation slice comprises an 8.9 mm*5.7 mm*1 mm aluminum nitride ceramic substrate. A silver paste conductor layer is printed on the back surface of the aluminum nitride ceramic substrate, silver paste wires are printed on the front surface of the aluminum nitride ceramic substrate, the two ends of each silver paste wire are respectively connected with a bonding pad, resistors are printed among the silver paste wires, high-temperature protection films are printed on the resistors, and acid and alkali-resistant protection films are printed on the silver paste wires and the high-temperature protection films. According to the attenuation slice, in the design thought, the circuit structure of the output end is optimized, standing waves of the output end are improved, and the inductance-capacitance performance of circuits is adjusted. Meanwhile, by accurate modification of the resistance value, the high-accuracy attenuation value is obtained. Various indexes of the aluminum nitride ceramic substrate 100 W-6 dB attenuation slice are good, and therefore the aluminum nitride ceramic substrate 100 W-6 dB attenuation slice meets the use requirements of present 4G networks.

The invention discloses an 8 dB attenuation piece with power capacity being 100 W. The 8 dB attenuation piece comprises an 8.9 mm *5.7 mm *1 mm aluminum nitride ceramic substrate. A silver paste back conductor layer is printed on the back face of the aluminum nitride ceramic substrate. Silver paste wires and five black resistors are printed on the front face of the aluminum nitride ceramic substrate, the silver paste wires are connected with the resistors, an attenuator circuit is formed, the areas of the five black resistors are different in size according to different absorption powers, the five black resistors are formed by two times of silk-screen printing, and the back conductor layer and the silver paste wires are communicated through end grounding paste, wherein the end ground paste is silver paste. According to the attenuation piece, attenuation of absorption of the resistors to power from input to output is considered from the design thought, the areas of the resistors are defined, meanwhile, the moving direction of the silver paste wires is optimized, standing waves of the circuit are improved, and high-accuracy attenuation values are acquired by accurately correcting resistance values. The 8 dB attenuation piece with power capacity being 100 W has excellent indicators and meets the use requirements of an existing 4G network.

The invention discloses an ultra-wideband antenna, which comprises a top loading plate and a metal floor which are opposite to each other, a radiation part positioned between the top loading plate and the metal floor, and a short circuit column and a parasitic oscillator which are arranged between the metal floor and the top loading plate, the radiation part is of an axial symmetry structure, the symmetry axis penetrates through the center of the top loading plate and the center of the metal floor, the radiation part comprises a first radiation body and a second radiation body which are arranged in an axial symmetry mode and located on the same plane, each radiation body is in a knife shape, the inner side edges of the radiation bodies are connected in a back-to-back mode, and grooves and side loading strips are formed in the outer side edges of the radiation bodies. And the side loading strips are parallel to the symmetry axis and extend towards the direction of the metal floor. According to the invention, the elliptical disc-shaped top loading plate, the grooves in meandering flow design and the side loading strips are adopted, so that the size of the antenna is effectively reduced, the working bandwidth of the antenna is widened, and meanwhile, the side loading strips can be grounded and / or the widths of the side loading strips and the parasitic oscillators are reasonably designed, so that the high-frequency and low-frequency radiation characteristics of the antenna are adjusted, and the gain is improved.

The invention discloses a high-precision 100-watt 14dB attenuation plate. The high-precision 100-watt 14dB attenuation plate comprises an aluminum nitride substrate which is 5.7 mm wide, 8.8 mm long and 1.0 mm thick, a back conducting layer is printed on the back face of the aluminum nitride substrate, a wire and film-like resistors are printed on the front face of the aluminum nitride substrate, the wire is connected with the film-like resistors to form a TT type attenuation circuit, the attenuation circuit is symmetric about the centerline of the aluminum nitride substrate, the output end and the input end of the attenuation circuit are respectively connected with a bonding pad, and the bonding pads are symmetric about the centerline of the aluminum nitride substrate. According to the design of the attenuation plate, various performance indexes are fully considered, the high-frequency and noninductive purposes are achieved, the situation that an original attenuation plate can only be applied to low frequency is broken, the application requirements of a current 4G network can be met, and meanwhile a series product line of 100-watt fixed film-like resistor type attenuation plates is extended.

The invention relates to a multi-feed-source double-frequency high-separation wide-beam high-stability phase centre antennae. The multi-feed-source double-frequency high-separation wide-beam high-stability phase centre antennae comprises an antenna cap and a metal inverted frustum substrate, wherein the metal inverted frustum substrate is internally provided with a first power divider and a second power divider, first and second radiating antennas are arranged in the antenna cap and on the metal inverted frustum substrate and are fixed through hollow short circuit screws, and a first coaxial cable is arranged between the first radiating antenna and the metal inverted frustum substrate; one end of an inner core is connected with a radiation fin of the first radiating antenna, the other end of the inner core is connected with a first branch of the first power divider, one end of a shielding layer is connected with ground of the first radiating antenna, and the other end of the shielding layer is connected with the ground of the first power divider; a fifth coaxial cable is arranged between the second radiating antenna and the metal inverted frustum substrate and the fifth coaxial cable passes through the hollow short circuit screws, and the inner core of the fifth coaxial cable is respectively connected with the ground of the second radiating antenna and the first branch of the second power divider; and the shielding layer is respectively connected with the radiation fin of the second radiating antenna and the ground of the second power divider.

The invention discloses a 4dB attenuator with a 100w power capacity. The attenuator comprises an aluminum nitride ceramic substrate 8.9mm in length, 5.7mm in width and 1.0mm in thickness. A silver paste back conduction layer is printed on the back of the aluminum nitride ceramic substrate. A sliver paste wire is printed on the front of the aluminum nitride ceramic substrate. The sliver paste wire is communicated with a whole circuit through black resistors printed. The areas of the black resistors are differed according to different absorbing powers. The black resistors are made by double silk-screen printing. The sliver paste back conduction layer and the sliver paste wire are communicated through end ground paste which is sliver paste. According to the design concept, the attenuator has the advantages that the fact that the attenuator attenuates power absorptions of the resistors from input to output is considered, the area of each resistor is defined, the trend of the sliver paste wire is optimized, standing wave of the circuit is improved, a precise attenuation is obtained by precisely correcting a resistance, indicators of the attenuator are all excellent, and the requirement for application in the existing 4G network is met.