365 results about "Return loss" patented technology

The invention discloses an orthogonal directional coupler and a microwave system based on a micro-coaxial technology, the orthogonal directional coupler comprises a metal outer conductor, an upper inner conductor and a lower inner conductor, the upper inner conductor and the lower inner conductor are suspended in the metal outer conductor through a periodic medium support loading structure; the upper inner conductor and the lower inner conductor serve as two identical micro coaxial coupling lines to be cascaded, the micro coaxial coupling lines are symmetrical multi-stage impedance stepped couplers, each micro coaxial coupling line is provided with n coupling units, the coupler structure is symmetrical about the center coupling unit, the upper inner conductor and the lower inner conductor are overlapped in the axial direction at the center coupling unit, and the upper inner conductor and the lower inner conductor are overlapped in the axial direction at the center coupling unit. The upper inner conductor and the lower inner conductor extend from the center coupling unit to the two ends, the upper inner conductor and the lower inner conductor deviate from the center to the two sides, and the closer to the coupling units at the two ends, the larger the offset is; the ultra-wideband orthogonal antenna can work in the frequency range of 5 GHz to 100 GHz, the return loss is superior to 15 dB, the phase change is smaller than 5.5 degrees, the directivity is superior to 10 dB, and the ultra-wideband orthogonal antenna can be used for generating ultra-wideband orthogonal signals.

The invention provides a comprehensive shielding signal cable and a manufacturing method thereof.The comprehensive shielding signal cable comprises a cable core and a protective layer wrapping the cable core, and the protective layer sequentially comprises a composite shielding layer and an outer sheath layer from inside to outside; the composite shielding layer comprises an iron-based amorphous nanocrystalline alloy layer, a 3D woven mesh layer and a conductive polymer coating which are sequentially arranged on the outer side of the cable core from inside to outside; through the gradient composite structure of the iron-based amorphous nanocrystalline alloy layer (low-frequency magnetic shielding), the 3D woven mesh layer (medium-frequency electromagnetic shielding) and the conductive polymer coating (high-frequency electric field shielding), the full-band shielding effectiveness is realized for the first time, meanwhile, the return loss is greatly reduced, the electromagnetic transmission performance and reliability of the cable are improved, and the service life of the cable is prolonged. And the structural stability of the cable is improved.

Provided in the present disclosure are a patch antenna, an antenna array and a communication device. The patch antenna comprises: a feed circuit, a slotted ground plane, and a first patch layer, a second patch layer and a third patch layer, which are sequentially stacked in the direction of the slotted ground plane facing away from the feed circuit and are spaced apart from each other, wherein the feed circuit comprises two feed ports and an open-loop annular feed portion connecting the two feed ports; the slotted ground plane is located on one side of the feed circuit; the slotted ground plane is provided with a plurality of slots; the slotted ground plane is spaced apart from the feed circuit; the orthographic projections of the slots on the feed circuit at least partially overlap the open-loop annular feed portion; and the first patch layer comprises a first patch, the second patch layer comprises a second patch, and the third patch layer comprises a first annular patch. The simplification of the structure of a polarization switchable antenna, the reduction of the return loss and the increase of the signal gain and impedance bandwidth are facilitated.

The invention discloses a frequency synthesizer, and relates to the technical field of communication hardware. The frequency synthesizer comprises a six-layer substrate and a plurality of elements, layout and wiring are reasonably performed in the six-layer substrate, the elements are placed in a limited space, then a coplanar waveguide transmission line model is adopted for a loop filter part, and shielding holes are selected to be added to the position away from the metal edge to reduce return loss and insertion loss. According to the frequency synthesizer, the return loss reaches-30dB or below, the insertion loss is lower than 0.05 dB, a bonding pad and a through hole are adopted for connection aiming at an output high-frequency signal line, a metal column type quasi-coaxial structure and a shielding hole are added to optimize the return loss and the insertion loss, the frequency synthesizer is miniaturized and high in performance, and the frequency synthesizer is suitable for high-integration and miniaturized application scenes.

The invention discloses a circuit board printing control method and system based on signal transmission loss. And obtaining a target differential transmission line parameter and a circuit board lamination parameter. And establishing an electromagnetic simulation model, and simulating insertion loss, return loss and impedance discontinuous point distribution. The line width, the line spacing and the interlayer hollowed-out area of the differential transmission line are dynamically adjusted through the reinforcement learning model, the proportion of the line width to the shielding layer spacing is limited by a preset critical value, and the line spacing is configured based on the multiple relation of the shielding layer spacing. And a sectional optimization strategy is adopted for the corners of the transmission line. The ratio of the aperture to the diameter of the anti-pad is optimized, and impedance mutation is reduced. According to the method, the key parameters of the target differential transmission line and the circuit board lamination parameters are acquired, and the electromagnetic simulation model is combined with the multi-physical field coupling algorithm, so that the insertion loss, the return loss and the impedance discontinuous point distribution can be accurately simulated. The method improves the adjustment efficiency, guarantees the accuracy of an adjustment result, and effectively reduces the signal transmission loss.

Methods and systems are described for split ring resonators. The split ring resonator can work as a filter that blocks 0.6GHz to 1GHz and thus acts as a tuning element and reduces coupling between columns. Certain features, such as trace elements, can reduce the Radar cross section at mid band frequencies (1.4GHz-2.6GHz) thereby unaffecting the mid bands radiators. Embodiments can also boost return loss, which is very uncommon on several other tuning pieces in the prior art.

The invention discloses a TSV-based multi-layer microsystem interconnection module total dose effect simulation modeling method, and relates to the technical field of three-dimensional integrated microsystems, and the method comprises the steps: obtaining geometric parameters and material parameters of a multi-layer three-dimensional microsystem interconnection module, building a finite element model of a microsystem module based on the geometric parameters and the material parameters, and carrying out the simulation modeling of the TSV-based multi-layer microsystem interconnection module total dose effect. Setting boundary conditions and port excitation; scattering parameters under different material conditions in the finite element model are extracted, frequency points are fixed, and a relational expression of the scattering parameters and material parameters is established; an RLC equivalent circuit model is constructed, and an equivalent circuit extraction method is obtained; according to an equivalent circuit extraction method, in combination with a relational expression of scattering parameters and material parameters, establishing a relationship between return loss parameters and equivalent circuit parameters; and establishing a relation model between the radiation dose and the resistance, inductance and capacitance in the equivalent circuit according to the relation between the return loss parameter and the equivalent circuit parameter. According to the invention, a scientific basis is provided for the reliability design of the three-dimensional microsystem in the radiation environment.

The invention provides a dual-band metasurface antenna array applied to radar imaging, which comprises at least one metasurface antenna unit arranged in an array, and the metasurface antenna unit is provided from top to bottom: a metasurface layer, the surface of which is laid with a patch group for exciting a characteristic mode, the patch group comprises a plurality of square patches which are laid in a square area and a plurality of right triangle patches which are separately arranged at the corners of the square area, and at least one gap is etched in at least one square patch; a first dielectric layer; the seamed grounding plate is etched with a drum-shaped gap; a second dielectric layer; and the feeder line layer comprises a long-strip feeder line and a T-shaped power divider arranged at the top of the long-strip feeder line, the antenna is excellent in return loss, gain, radiation pattern and the like, has relatively wide dual-frequency working bandwidth and remarkable high gain, and can meet the application requirements of wireless communication, radar systems and other high-performance signal transmission.

The present disclosure is directed to low noise amplifiers built as a monolithic millimeter or microwave integrated circuit (MMIC) that includes an amplification stage with two or more field effect transistors (FETS) connected in a parallel configuration. An amplifier may include two, three, or more amplification stages. Amplifiers consistent with the present disclosure may operate at frequencies in the range of 3 gigahertz (GHz) to 9 GHz. Each transistor or amplification stage may include their own series feedback element. A second amplification stage may include two parallel transistors, with one having a series feedback element and a feedback shunt spanning the second stage. A third stage may include a single transistor. Each of the transistors connected in a parallel configuration may be tuned to a different corner frequency in order to improve metrics of noise figure, gain, input return loss, and output return loss not possible with conventional amplifier designs.

The invention relates to the technical field of optical communication equipment testing, in particular to an integrated optical module multi-parameter testing system and method.The method comprises the steps that a multi-channel parallel testing unit synchronously collects light spot morphology, divergence angles, insertion loss and return loss space and transmission characteristic parameters through a transmission light path and a reflection light path; the parameter collaborative analysis module performs nonlinear correlation analysis and dynamic performance threshold evaluation based on a cross-dimension correlation model; the intelligent calibration engine dynamically adjusts the test benchmark and compensation parameters according to the environment temperature and the equipment aging attenuation model; the fault diagnosis and prediction unit identifies potential defect types of the collimator, constructs a performance degradation prediction model in combination with a working state and environmental stress, and predicts a performance evolution trend according to test data; and the test report generation module automatically generates a standardized and customized dual-mode test report, a quality grade label and a performance optimization suggestion according to the prediction result and the diagnosis conclusion. Therefore, the problems of poor test precision, low test efficiency and the like in the prior art are solved.

The invention relates to a slip ring wireless transmission structure applied to X-ray tomography equipment, which comprises a transmitting antenna and a receiving antenna, the transmitting antenna is composed of a transmitting transmission line and a transmitting adapter plate, the transmitting antenna is arranged on the radial outer side surface of a slip ring, and the receiving antenna is fixed on an equipment rack. The structures of the matching end of the transmitting antenna, the transmitting conversion plate and the receiving antenna are optimally designed, and the microstrip line with a periodic structure is used in the transmitting transmission line, so that compared with the wireless transmission structure of the existing equipment, the near-field coupling efficiency is improved, the return loss of the system is effectively improved, the signal-to-noise ratio is reduced, and the transmission efficiency is improved. Therefore, the transmission stability and reliability are effectively improved, and the use requirements of CT equipment can be better met.

The utility model relates to the technical field of optical communication, in particular to a waveguide terminator and an optical module.The waveguide terminator comprises an optical absorber and a transmission waveguide which are stacked and arranged at intervals; wherein the transmission waveguide comprises a first waveguide section and a second waveguide section, and the second waveguide section is located in a projection area of the light absorber and used for diverging a light field. One end of the first waveguide section is connected with the second waveguide section, and the other end of the first waveguide section extends out of the projection area of the light absorber and is used for transmitting externally input incident light to the second waveguide section. And the included angle between the tangent line of the first waveguide section at the boundary of the projection area of the light absorber and the boundary is smaller than 90 degrees, so that a small amount of light reflected at the boundary of which the refractive index suddenly changes can enter the cladding to be dissipated, additional return loss is avoided as far as possible, and the return loss of the optical chip can be further reduced.

A power amplifier with improved stability, gain, flatness and return loss and reduced the size, which comprises a two-stage power amplifier in balanced cascode topology that consists of a first common-source stage feeding into a first common-gate stage; a second common-source stage feeding into a second common-gate stage; an input matching network for matching the input impedance of the a two-stage power amplifier to a desired signal source impedance; an output matching network for matching the output impedance of the a two-stage power amplifier to a desired load; a first positive feedback path between the gate of the first common-source stage and the drain of the second common-gate (CG) stage and a second positive feedback path between the gate of the second common-source stage and the drain of the first common-gate (CG) stage; a first negative feedback path between the drain of the first common-gate (CG) stage and the gate of the first common-source stage and a second negative feedback path between the drain of the second common-gate (CG) stage and the gate of the second common-source stage; a first inter-stage matching network between the first common-source (CS) stage and the first common-gate (CG) stage; and a second inter-stage matching network between the second common-source (CS) stage and the second common-gate (CG) stage.

The broadband coaxial-to-microstrip line converter comprises a coaxial line, a gold strip and a substrate, the coaxial line comprises a coaxial outer conductor, a central medium and a coaxial inner conductor which are arranged from outside to inside, the coaxial inner conductor at one end of the coaxial line is shorter than the coaxial outer conductor, and a containing space for installing the gold strip and the substrate is formed. The substrate comprises a top-layer conduction band, a middle insulating layer and a bottom-layer conduction band, the top-layer conduction band comprises a top-layer gradual change area and a microstrip line which are located on the same center line with the coaxial inner conductor, and the bottom-layer conduction band is provided with a gradual change hollow area right below the top-layer gradual change area to jointly form a mode gradual change area. According to the utility model, the structure is exquisite, a TEM mode transmitted in a coaxial line can be smoothly transited to a quasi TEM mode transmitted by a microstrip line, the working bandwidth of the whole conversion circuit is effectively improved, the working frequency can reach up to 50GHz, and the return loss of each frequency point is less than-15dB.

The present invention discloses a microwave topological photonic crystal metasurface antenna, which belongs to the field of communication technology. The present invention adopts a layered structure similar to a patch antenna, including a ground plate, a dielectric layer, a topological photonic crystal, a rectangular metal frame, and a microstrip feeder arranged from bottom to top. The topological photonic crystal is arranged above the dielectric layer, the rectangular metal frame is coated on the periphery of the topological photonic crystal, and the microstrip feeder is connected to the rectangular metal frame. The present invention can achieve multi-band characteristics and extended bandwidth. In addition, most of the electromagnetic waves propagated by the antenna within the band gap range are suppressed, and only electromagnetic waves of the angular state frequency can propagate, with smaller return loss, and the topological angular state can achieve unidirectional radiation, with better directivity at high frequencies. As a result, the antenna performance is greatly improved, which is very suitable for on-chip optical interconnection and photonic chip integration, and meets the needs of 5G / 6G communications, quantum computing, etc. for miniaturized devices.

The invention relates to the technical field of optical fiber connector connection monitoring, in particular to an AI-based optical fiber connector connection reliability monitoring method and system, and the method comprises the steps: constructing a multi-mode monitoring data source through synchronously collecting time sequence parameters including optical power, insertion loss, return loss and other physical quantities and a connector end face image, the image is subjected to feature mapping through the convolutional neural network, spatial features of pollution, scratches and alignment deviation are automatically extracted, manual inspection is replaced, and the recognition efficiency and objectivity are improved. Time sequence parameters are input into the modeling performance evolution trend of the long-short-term memory network, and weak dynamic characteristics such as chronic degradation are effectively captured. And through fusing image space features and parameter trend features, strengthening key factor characterization, and outputting a reliability determination result of the connector through a residual error classification network, accurate classification of normal, to-be-maintained and fault states is realized, traceability alarm information can be generated, and intelligent monitoring and early warning of the operation state of the connector are realized.

The present invention relates to an adaptive matching circuit and a matching method for a magnetic resonance radio frequency coil, and belongs to the field of magnetic resonance imaging technology. The circuit includes a receiving coil, an adjustable matching circuit, a radio frequency switch, a return loss detection circuit, and a single-chip control circuit; the circuit uses a binary method to adjust the voltage value across the variable capacitance diode in the adjustable matching circuit, and automatically detects the adaptation of the matching circuit through the return loss detection circuit to achieve instant adaptive circuit matching, and through the joint action of the adjustable matching circuit, the radio frequency switch, and the single-chip control circuit, the return loss at the center frequency point of the receiving coil reaches the maximum value to achieve the best matching. The present invention can effectively avoid the situation where the matching circuit cannot match, and improve the transmission efficiency of high-frequency signal energy.

The invention provides a low-coupling rewiring packaging structure and a preparation method thereof, and relates to the chip packaging technology, the packaging structure comprises a chip, a plastic package body, a dielectric layer, a reconfiguration circuit layer and solder balls, and the front surface of the chip is provided with a metal layer; the plastic package body wraps the periphery of the chip; the dielectric layer is arranged on the surface of the metal layer and covers the plastic package body; the reconstruction line layer is arranged in the dielectric layer and is connected with the metal layer; the solder ball is arranged on one side, far away from the chip, of the dielectric layer and is connected with the reconfiguration circuit layer; wherein the metal layer is etched to form an avoiding gap, the avoiding gap penetrates through the metal layer, and the projection of the reconstruction circuit layer on the front surface of the chip is at least partially overlapped with the avoiding gap. Compared with the prior art, by forming the avoiding gap overlapped with the reconstruction circuit layer on the metal layer, the overlapping area of the reconstruction circuit layer and the metal layer can be greatly reduced, the coupling effect with the RDL is reduced, and the return loss result of a high-frequency signal is greatly improved.

The invention discloses a broadband double-layer interconnection structure based on a silicon adapter plate technology, and belongs to the technical field of radio frequency microsystems. According to the method, a three-dimensional compensation structure is formed by adding square conductive metal and TSVs into lower-layer metal at one end, close to a transition structure, of an original coplanar waveguide transmission line, and a resonance point with return loss of-51dB is introduced at 17.59 GHz, so that the broadband interconnection effect that the return loss of 0-33GHz is smaller than or equal to-20dB is achieved, and the in-band insertion loss fluctuation value is reduced by 11.6% compared with that of the original structure. Compared with a traditional interconnection structure broadband design, the method has the advantages that on the premise that the plane area is not increased, the broadband interconnection design difficulty is greatly reduced through the three-dimensional structure design.

The invention discloses a method and device for measuring electrical input and output performance in a high-speed optical module, and the device is characterized in that an optical module golden finger interface module is connected with multiple groups of P / N poles of a to-be-measured high-speed optical module through golden fingers before a finished product is assembled; the electric switch chip is connected with the golden finger interface; the controller controls the on-off of the plurality of groups of P / N poles through the electric switch chip; the network distribution test equipment controls electric signals with different frequencies to be output to a group of P / N poles of the high-speed optical module to be tested every time under a test control signal of the industrial personal computer, acquires return loss electric signals generated by the high-speed optical module to be tested through the group of P / N poles, generates a frequency-return loss electric signal atlas and sends the atlas to the industrial personal computer; and the industrial personal computer enables the spectrum of the frequency-return loss electric signal to correspond to the channel of the high-speed optical module to be detected, and judges whether the high-speed optical module to be detected is qualified or not according to a preset return loss condition. According to the invention, defective products of the optical modules can be screened out before the optical modules are assembled into finished products.

The invention discloses a 16-in-one high-power combiner working in a radio frequency band, and belongs to the technical field of fusion radio frequency heating. The invention comprises a coaxial input hard feeder line, a radial transmission line (RTL), a gradient impedance matching coaxial line and a coaxial output hard feeder line. The physical size is designed through theoretical calculation, electromagnetic field distribution is optimized through simulation, 16 radio-frequency signal input ports are designed through radial symmetric topology, a radial transmission line serves as a main synthesis path of radio-frequency signal source power, the power input by the 16 radio-frequency signal source ports is subjected to one-step efficient synthesis in the center of the radial transmission line, and the radio-frequency signal source power is obtained. And the 50-ohm characteristic impedance standard output of the synthesized radio frequency signal power is realized through an impedance matching technology. The sixteen-in-one power combiner designed by the invention has the characteristics of high synthesis efficiency, symmetrical structure, good amplitude and phase consistency, high isolation, low return loss, low reflection loss, simple design structure, easiness in manufacturing and the like.

The invention relates to an optical fiber insertion loss and return loss test management system and method, an optical power detection module comprises an input optical power detection unit, an output optical power detection unit and a reflected light power detection unit, and further comprises an optical emission module, an optical switch matrix and a data processing module, and the optical emission module is a quantum dot tunable laser module; the optical switch matrix is a bionic optical switch matrix, and multi-channel optical path reconstruction is realized; the optical power detection module is internally provided with a multi-physical field sensing array and detects optical power data in real time; the data processing module is used for receiving the optical power data and processing the data; comprising a test module for acquiring optical power data based on the optical power detection module and calculating optical fiber insertion loss and optical fiber return loss according to the acquired optical power data. The technical problems that the insertion loss measurement error is influenced by temperature drift, the switching time of an optical switch is too long, the rapid detection requirement of a 5G bearing network for batch optical fibers is difficult to meet, the real-time sensing and compensation capability is lacked, and the test result is not accurate in a complex environment are solved.

The invention provides a packaging structure, an optical module and an optical communication system. The packaging structure comprises an insertion core which comprises an optical fiber which is used for transmitting signal light; the pipe cap comprises a lens, and the lens is used for focusing the signal light; the tube base is matched with the tube cap to form a containing cavity, a light receiving chip is arranged in the containing cavity and used for receiving focused signal light, and the included angle between the normal of the plane where the light receiving chip is located and the main optical axis of the lens is larger than 0 degree. Therefore, the focused signal light received by the light receiving chip can form large-angle reflection at the light receiving chip, so that most of the signal light reflected by the light receiving chip is emitted from the edge of the lens and cannot be converged at the optical fiber, and the return loss capability of the packaging structure is improved.

The invention discloses a compact cross orthogonal scanning multilayer millimeter wave multi-beam array antenna, which comprises a dual-port common-cavity Rotmann lens feed network structure and a common-caliber antenna layer, and is characterized in that the dual-port common-cavity Rotmann lens feed network structure is located at a bottom layer, and the common-caliber antenna layer is located above the common-cavity Rotmann lens feed network structure; the common-aperture antenna layer comprises a slot antenna layer and a patch antenna layer, the slot antenna layer is located at the bottom layer, and the patch antenna layer is located above the slot antenna layer. According to the invention, the return loss of each port is reduced, the reflection of incident waves at the edge ports is reduced, the isolation degree between the ports and between the two sub-lenses is increased, and the working efficiency is improved.

The invention discloses an ultra-wideband small-phase-shift digital phase shift circuit and a simulation method thereof, the ultra-wideband small-phase-shift digital phase shift circuit comprises an ultra-wideband phase shift network, the ultra-wideband phase shift network adopts a bridge T-shaped network embedded with an all-pass network structure, and the all-pass network structure is a dual-port transformer network formed by winding two mutual coupling inductors. The bridge T network structure can realize miniaturization design, the all-pass network structure can realize ultra-wideband design, the bridge T network structure has better performance than a common switch, the phase shifter has wider bandwidth, higher phase shifting precision and better return loss than the common switch, and the all-pass network is suitable for the ultra-wideband characteristic. And the two are combined to improve the performance of the small-shift phase. The all-pass network structure is embedded between the input port and the output port of the bridge T-shaped network structure, phase delay can be increased, bandwidth expansion is guaranteed, and meanwhile it is guaranteed that phase shifting precision is not changed.

The invention belongs to the technical field of microwave filter design, and particularly relates to a microstrip filter of a CQ frequency-variable coupling structure and a design method of the microstrip filter. The method comprises the following steps: firstly, according to required filter indexes, such as order, center frequency, bandwidth, return loss and transmission zero position, solving a transverse matrix M of a filter by utilizing a filter comprehensive theory; then performing similarity transformation and scaling transformation on the transverse matrix to eliminate unnecessary coupling terms in the transverse matrix so as to obtain a filter topological structure and a frequency-dependent coupling matrix M'which are easier to implement; a quarter-wavelength short-circuit stepped impedance resonator is selected as a resonance unit of the micro-strip filter simulation model; finally, relevant coupling parameters of the micro-strip filter simulation model are made to approach the theoretical coupling coefficient by adjusting relevant physical structure parameters of the resonator, and then design is completed. By introducing a frequency-dependent coupling mechanism into the structure, the position of a transmission zero point is flexible and controllable, and the spectrum selectivity and the out-of-band rejection capability of the filter can be effectively improved.

The invention provides an antenna test method and an antenna test system. The antenna test method comprises the following steps: acquiring test parameters of n to-be-tested products; the test parameters comprise any one of return loss, voltage standing wave ratio and reflection coefficient; determining a feature mean value of the n to-be-tested products based on the test parameters of the n to-be-tested products; determining a feature deviation mean value of the pth to-be-tested product based on the test parameters and the feature mean value of the pth to-be-tested product in the n to-be-tested products; if the characteristic deviation mean value is greater than or equal to a first preset value, determining that the pth to-be-detected product does not meet a preset requirement; n and p are integers, n is greater than or equal to 2, and p is greater than or equal to 1 and less than or equal to n. According to the application, the test parameters of the n to-be-tested products are introduced into the test evaluation of the pth to-be-tested product to obtain the feature deviation mean value of the pth to-be-tested product, so that the accuracy of the test result and the consistency of the to-be-tested products can be improved.

The invention provides a system and a method for measuring insertion loss and return loss of a multi-core optical fiber link based on an OFDR (Optical Frequency Domain Reflectometer), and belongs to the field of optical fiber link diagnosis and measurement. The system is composed of a multi-wavelength laser, three wavelength division multiplexers, two couplers, N circulators, a photoelectric detector, a data acquisition card, a to-be-measured link and an upper computer, the multi-wavelength laser outputs laser with N wavelengths, the wavelength division multiplexers multiplex signals and then divide the signals into signal light and reference light through a first coupler, the signal light is used for being output to the to-be-measured link, and the reference light is used for being output to the to-be-measured link. A mixing signal formed by the reflected light of the to-be-measured link and the reference light interferes in the photoelectric detector, a coherent mixing signal containing the insertion loss and return loss information of the to-be-measured link is measured, and the insertion loss and return loss of each node of the to-be-measured link can be calculated by analyzing the coherent mixing signal. By using the OFDR technology, the full-range measurement from the starting point to the ending point of the optical fiber is realized, so that the OFDR can comprehensively diagnose the health state of the optical fiber link.

The invention discloses a stacked miniaturized broadband circulator, and belongs to the technical field of microwave passive radio frequency device engineering. The problems that an existing circulator is narrow in working bandwidth, large in size, large in insertion loss and the like are solved. Through the vertical interconnection technology, the matching line circuit and the central junction circuit are designed on different layers of dielectric substrates, so that the size of the circulator is greatly reduced, and the size under the relative center frequency is only 0.14 lambda0 * 0.14 lambda0. And the metal ground is designed between the two substrates, so that the two layers of microstrip circuits share one layer of metal ground, and the structure is simplified. And according to a simulation result, the performance is very excellent, the insertion loss is kept within 1dB in a broadband, and the return loss is kept below-15dB. Compared with an existing circulator, the circulator provided by the invention effectively overcomes the technical problems of antenna receiving and transmitting integration, inter-stage isolation and the like, and has the remarkable advantages of small size, simple design scheme and excellent performance.

The utility model relates to the technical field of optical communication testing, in particular to an insertion loss and return loss testing butt joint tool. Comprising a bottom plate, and a standard line positioning block is arranged on the bottom plate and used for positioning a standard line; a slide rail is arranged on the bottom plate, a slide block is arranged on the slide rail, and a test line positioning block is arranged on the slide block and used for positioning a test line; the slide block slides on the slide rail, so that the test line positioning block moves in the direction close to or away from the standard line positioning block; a mounting groove is formed in the standard line positioning block, and a standard line connector is arranged in the mounting groove; a limiting block is arranged on the standard line positioning block, an elastic piece is arranged on the limiting block, one end, far away from the limiting block, of the elastic piece abuts against the standard line connector, and the limiting block and the standard line connector are matched to release or extrude the elastic piece through sliding of the standard line connector in the mounting groove in the direction close to or far away from the test line positioning block. The method has the advantages that damage to the end face of the workpiece in the insertion loss test is reduced, and the test efficiency is improved.