57 results about "Ka band" patented technology

The invention relates to a farmland parcel identification method based on optical-Ka frequency band SAR feature fusion, and the method comprises the steps: carrying out the feature extraction of an optical remote sensing image through employing an improved ResNet50 network, carrying out the feature extraction of a Ka-SAR image through employing a complex convolution network, triggering a gating mechanism when the cloud coverage rate of the optical remote sensing image exceeds a threshold value, and carrying out the recognition of a farmland parcel. If the cloud coverage rate of the optical remote sensing image does not exceed the threshold value, carrying out feature fusion by adopting a cross-modal attention fusion mechanism; and outputting a farmland plot identification probability graph based on the obtained fusion features based on a UNet + + decoder, and performing optimization and iteration on a result by adopting a geometric constraint loss function to obtain a final identification model. The cross-modal attention fusion method is adopted to perform feature fusion, physical-level collaborative fusion for data features is realized, and meanwhile, the problem that an output result does not meet agricultural management requirements due to the fact that farmland parcels cannot be completely recognized and specific regular geometric attributes of farmland are ignored in a multi-cloud scene is solved.

The invention discloses a low-profile and high-integration broadband dual-circularly-polarized transceiving common-aperture phased-array antenna, which adopts a multi-layer PCB (Printed Circuit Board) laminated structure, comprises a radiation patch layer, a quasi-rectangular patch layer, a metal reflection ground layer and a feed layer from top to bottom, and is combined with a metalized blind hole and a buried hole to form a complete coupling path. A U-shaped groove, a U-shaped metal strip and a C-shaped groove are integrated on a metal reflection ground, and a staggered groove is loaded on a quasi-rectangular patch, so that a K / Ka dual-band separated dual-coupled feed structure is realized, and dual circularly polarized radiation is obtained under the same aperture. The antenna is further provided with outer ring and inner ring plated-through hole arrays, the outer ring plated-through hole arrays are used for constructing an isolation area to improve the isolation degree between wavebands, and the inner ring plated-through hole arrays introduce a horizontal electric field component to improve the circular polarization purity and expand the axial ratio bandwidth. Wide impedance bandwidth and wide axial ratio bandwidth are realized in the K wave band and the Ka wave band, the isolation degree is high, the profile is low, the structure is compact, and the broadband phased array antenna is suitable for broadband phased array systems such as satellite communication terminals and mobile platforms.

The invention belongs to the technical field of antennas, discloses a double-frequency common-caliber high-isolation phased-array antenna in a sparse array distribution mode, and mainly solves the problems that an existing double-frequency common-caliber array antenna sparse distribution optimization algorithm is large in calculation amount and low in design efficiency. According to the invention, through the thirteen-sided Einstein pattern, aperiodic tiling of an infinite plane can be realized through a certain splicing rule. A Ka-band high-frequency antenna and a K-band low-frequency antenna are placed at the gravity center of the Einstein pattern, and the high-frequency antenna and the low-frequency antenna are distributed in a staggered mode in a translation mode. The antenna unit adopts a cross symmetric array antenna, and high isolation of the dual-frequency antenna unit is realized by loading a coaxial filter at the bottom of the antenna unit. The rear end of each antenna unit is connected with a T / R assembly, and array beam scanning is realized by controlling the amplitude and phase of an input signal. The method is low in arrangement cost and high in design efficiency, and can be used for radar, communication, navigation and information confrontation.

The invention provides a multi-band composite high-integration TR assembly. The multi-band composite high-integration TR assembly comprises a shell, a front multi-layer board, a back multi-layer board, a C / X / Ku band receiving and transmitting circuit, a C / X / Ku band single receiving circuit and a Ka band receiving and transmitting circuit, wherein the front multi-layer board and the back multi-layer board are connected in the shell, the C / X / Ku band receiving and transmitting circuit is connected with the front multi-layer board, and the Ka band receiving and transmitting circuit is connected with the back multi-layer board. The low-cost scheme design of an all-solid-state microwave multilayer board suitable for batch production and testing is adopted, ports and transmission line layout are reasonably designed, multi-band composite mode transmission is achieved in the form of the front face and the back face, a C / X / Ku-band transmitting circuit and an H-polarization receiving circuit are integrated on the front face, and the transmission efficiency is improved. A C / X / Ku frequency band V polarization receiving circuit and a Ka frequency band receiving and transmitting circuit are integrated on the reverse side, different functional circuits are respectively transmitted through a microstrip line and a strip line through an interface circuit structure covering 1-40 GHz and an in-board vertical transition structure, the isolation degree of different circuits is improved, mutual crosstalk between different signals is avoided, and the transmission efficiency is improved. And the functions of high integration, high consistency, ultra wide band, numerical control phase shift, numerical control attenuation and the like of the assembly are realized.

The application belongs to the technical field of antennas, and discloses an S / Ka-band common-aperture antenna and communication equipment, which comprises a first dielectric plate and a second dielectric plate stacked from top to bottom; the top surface, the middle and the bottom surface of the first dielectric plate are respectively provided with a rectangular patch array, a first metal through hole and a first metal layer; wherein the rectangular patch array, the first metal through hole and the first metal layer form a magneto-electric dipole antenna array; the magneto-electric dipole antenna array works in the Ka-band and is used for realizing satellite communication; the top surface, the middle and the bottom surface of the second dielectric plate are respectively provided with a second metal layer, a second metal through hole and a third metal layer; wherein the second metal layer, the second metal through hole and the third metal layer form a low-profile monopole antenna; the low-profile monopole antenna works in the S-band and is used for realizing ground equipment communication; the application has a simple structure, can realize different beams and polarization characteristics, effectively improves the space utilization rate of the antenna and has high integration.

The application provides an airborne dual-band weather radar detection method, which comprises the following steps: S1: adopting a dual-band common-aperture antenna to time-divisionally emit X-band electromagnetic waves and Ka-band electromagnetic waves; S2: a weather radar receives the X-band electromagnetic waves and the Ka-band electromagnetic waves and performs ground clutter suppression; S3: calculating reflectivity Rrf x according to the X-band electromagnetic waves; S4: calculating reflectivity Rrf ka , velocity V ka and spectral width W ka ; S5: performing analysis on weather targets and displaying analysis results. The detection method realizes cloud detection by using the Ka band on the basis of meeting original X-band weather rainfall detection functions, realizes dangerous weather identification and dangerous area warning by comprehensively considering the spatial structure of the cloud and Doppler information, marks weather seriously threatening flight safety in a display picture, and reminds pilots to pay attention. The detection method comprehensively improves the detection perception and display capability of the airborne weather radar on various weathers, further improves flight safety, and reduces unnecessary deviation.

This invention discloses a broadband circularly polarized integrated feed transmission array antenna covering the entire Ka-band, comprising an array surface and an integrated feed. The phase center of the integrated feed coincides with the focal point of the array surface, illuminating the array surface perpendicularly and forming a 45-degree angle with the array surface in the horizontal direction. The array surface comprises multiple array elements of different sizes arranged linearly. Each array element includes two orthogonally arranged first and second dielectric substrates, which have the same height but different thicknesses. The integrated feed comprises a stacked first and second PCB board. A substrate integrated waveguide is disposed on the first PCB board with coupling slots, and a substrate integrated waveguide cavity and annular metal patches surrounding the substrate integrated waveguide cavity are disposed on the second PCB board. This invention achieves a wide axial ratio bandwidth and gain bandwidth, and has the advantages of low profile, light weight, easy fabrication, and low cost.

This invention discloses a user-end beam control system for a KuKa dual-band multi-beam antenna, comprising: an FPGA module for receiving instruction information from a payload integrated electronics system, generating various control signals and sending them to the KuKa dual-band multi-beam antenna, and also for receiving telemetry information from the KuKa dual-band multi-beam antenna, integrating it into a telemetry data packet and sending it to the payload integrated electronics system; a clock management module for receiving a reference clock signal from an external frequency source and generating the operating clock required by the FPGA module; an interface module for providing a serial communication interface and serial driver, an LVDS control interface and driver, and a debugging interface; and a debugging module for debugging the software running within the FPGA chip. This invention can quickly and independently adjust the beam pointing of the Ku and Ka bands of the KuKa dual-band multi-beam antenna and acquire telemetry data from the KuKa dual-band multi-beam antenna in real time.

The application discloses a kind of low-orbit satellite ultra-wideband navigation signal acquisition method and system, to solve the existing low-orbit satellite ultra-wideband navigation signal acquisition method, signal can not be locked, finally lead to the technical problem of low acquisition success rate.It is to obtain the low-orbit satellite pseudo-random noise code corresponding to ka band low-orbit satellite signal and multiple low-orbit satellite ultra-wideband navigation signals;According to preset sampling rate, preset skip time, ka band low-orbit satellite signal, generate complex signal and original intermediate frequency signal;Based on each low-orbit satellite pseudo-random noise code, pseudo-code spectrum library construction is carried out, and the pseudo-code spectrum library is output;Based on the known intermediate frequency parameter of original intermediate frequency signal, determine the discrete frequency search sequence, and combine the complex signal, pseudo-code spectrum library to construct matrix, and output three-dimensional result matrix;Using three-dimensional result matrix, each low-orbit satellite ultra-wideband navigation signal is acquired and determined, and multiple acquisition successful low-orbit satellite ultra-wideband navigation signals are determined.

The application discloses a Ka-band eight-way power combiner, which comprises a shielding box body, wherein a straight-through input port, an input waveguide cavity, an input coplanar magic T, a secondary waveguide power division module, a waveguide-microstrip double-probe conversion structure, a secondary waveguide power synthesis module, an output waveguide cavity, an output coplanar magic T and a straight-through output port are sequentially arranged in the shielding box body along a signal transmission direction; the secondary waveguide power division module and the secondary waveguide power synthesis module both adopt an E-T junction structure and are integrated with a three-stage waveguide E-plane stepped structure, so as to realize impedance matching from an input end to an output end; the Ka-band eight-way power combiner has high synthesis efficiency, extremely low amplitude imbalance and phase imbalance in the Ka band through multi-stage waveguide impedance matching, optimized double-probe conversion and symmetrical layout design. The combiner has the advantages of compact structure, large power capacity, simple machining and assembly and good stability.

The invention relates to the technical field of microwave ferrite devices, and discloses a K-to-Ka waveband miniaturized broadband microstrip isolator, which comprises a permanent magnet, a ceramic chip, a soldering lug, a circuit layer, a resistive film and a single ferrite which are sequentially laminated from top to bottom, a single ferrite substrate is made of a gyromagnetic material, and the isolator realizes a gyromagnetic function through the single ferrite substrate. The K-to-Ka wave band miniaturized broadband microstrip isolator assists the single ferrite substrate in stably playing a gyromagnetic function, the soldering lug, the ceramic chip and the permanent magnet are stacked to assist in improving the overall performance of the isolator, and the ceramic chip can play a role in insulation and protection to avoid electrical interference between the permanent magnet and the soldering lug, so that the service life of the isolator is prolonged. The use reliability and safety of the isolator are improved, the installation space occupation in radar communication and satellite communication equipment can be reduced through the miniaturization design of the overall structure, the overall size and weight of auxiliary equipment are reduced, and the portability and space compatibility of the equipment are improved.

The invention belongs to the technical field of microwaves, and particularly relates to a slot line-half-mode SIW composite transmission line for microwave / millimeter wave transmission, which is characterized in that a half-mode SIW structure is arranged in a sandwich structure, and a first metal layer synchronously loads a conical microstrip feeder line and a horn-shaped microstrip feeder line structure; the second metal layer is used as a metal structure with a floor function, and the design mode of additionally loading a slot line and an interdigital capacitor enables the device to realize transmission of an S wave band and a Ka wave band at the same time. Wherein in the S wave band, the horn-shaped micro-strip structure of the first metal layer is used for carrying out coupled feeding on the slot line, and in the Ka wave band, the conical micro-strip structure of the first metal layer is used for directly feeding the half-mode SIW; meanwhile, the second metal layer loads an interdigital capacitor at the tail end of the half-mode SIW to complete filtering, and finally the composite transmission line feed structure supporting synchronous transmission of the half-mode SIW and the slot line is constructed. The machining process is simplified, and the machining cost is reduced.

The application discloses an interferometric SAR synchronization method of radar inter-satellite link combined with Ka-band link cross correction, and aims at the problems of interrupting normal SAR imaging or existing initial phase winding in the existing synchronization link method, and proposes a cross correction scheme of X-band radar inter-satellite link combined with Ka-band high-precision synchronization link. The system adopts a common reference source to ensure the phase correlation, and different synchronization time sequences are designed, that is, the X-band link is synchronized at a low frequency to eliminate the initial phase winding, and the Ka-band link is synchronized at a high frequency same as the SAR pulse repetition frequency (PRF) to realize high-precision phase measurement. During ground processing, the initial phase error of the Ka-band compensation function is corrected by using the X-band synchronization data, so that a high-precision phase synchronization compensation function is obtained, and the echo of the secondary satellite is compensated. The application solves the problem of initial phase winding under the premise of not interrupting the normal SAR imaging time sequence, and significantly improves the phase synchronization precision, image quality and absolute height measurement reliability of the dual-satellite interferometric SAR system.

The present application relates to a farmland plot recognition method based on optical-Ka band SAR feature fusion, which uses an improved ResNet50 network to extract features from optical remote sensing images, uses a complex convolution network to extract features from Ka-SAR images, triggers a gating mechanism when the cloud coverage of the optical remote sensing image exceeds a threshold, and uses a cross-modal attention fusion mechanism for feature fusion if the cloud coverage of the optical remote sensing image does not exceed the threshold; the obtained fusion features are output as farmland plot recognition probability maps based on a UNet++ decoder, and a geometric constraint loss function is used to optimize and iterate the results to obtain the final recognition model. The present application uses a cross-modal attention fusion method for feature fusion, realizes physical-level collaborative fusion of data features, and solves the problems of incomplete recognition of farmland plots in cloudy scenes and ignoring the specific regular geometric properties of farmland, which leads to output results that do not meet the needs of agricultural management.

The invention belongs to the technical field of millimeter wave phased-array antennas, and particularly discloses a circularly polarized spherical phased-array antenna for Ka-band operation, which comprises a hemispherical antenna base and a plurality of radiation units, the plurality of radiation units are arranged on the hemispherical surface of the hemispherical antenna base in an array form; the circularly polarized spherical phased-array antenna is configured in a frequency range from 27GHz to 29GHz, so that + / -90-degree beam scanning of any azimuth tangent plane is realized. The scanning angle limitation of a planar array is broken through, and + / -90-degree continuous scanning of any tangent plane is realized; meanwhile, the array element spacing and the arrangement density are optimized in combination with the short wavelength characteristic of the Ka wave band, the mutual coupling effect of the high frequency band is reduced, and the problem that the actual use effect is poor due to the fact that the large-angle scanning radiation capacity of an existing Ka wave band planar phased array antenna is limited and the polarization purity is reduced is solved.

The invention relates to a Ka frequency band broadband multi-beam communication system based on a 5GNTN system, which can work under the 5GNTN system through the cooperative work of a 4T4R radio frequency transceiver chip, a signal processing FPGA, a monitoring FPGA, a clock PLL, an optical module and a power supply module, and the Ka frequency band broadband multi-beam communication system can work under the 5GNTN system through the cooperation of the 4T4R radio frequency transceiver chip, the signal processing FPGA and the optical module. And the maximum support bandwidth of the system is greatly improved while the number of supported beams is greatly improved, so that the uplink and downlink rates reach the level of 5Gbps.

The present invention discloses a K / Ka band dual-frequency conical beam antenna, comprising a high-frequency filtering and feeding module, a low-frequency power splitting and feeding module, and a nested horn module; the nested horn module comprises a circular waveguide horn and a coaxial horn nested outside the circular waveguide horn; the high-frequency filtering and feeding module is used to filter and perform mode conversion on input high-frequency electromagnetic energy, and output electromagnetic waves in a coaxial TEM mode; the electromagnetic waves in the coaxial TEM mode are used to excite the circular waveguide horn; the low-frequency power splitting and feeding module is used to perform power distribution on the input low-frequency electromagnetic energy, and output a plurality of electromagnetic waves with equal amplitude and phase; the plurality of electromagnetic waves with equal amplitude and phase are used to symmetrically excite the coaxial horn; the present invention can realize the radiation characteristics of a dual-band dual-conical beam, effectively improving the detection range of the antenna; the filtering function is integrated in the high-frequency filtering and feeding module, effectively improving the anti-interference capability of the antenna; and at the same time, it has high power capacity and radiation efficiency.

A Ka band monopulse antenna system with a compact size (diameter: 160 mm; height: 25 mm). The monopulse antenna system consists of a monopulse comparator; an unequal power divider and an array of 448 radiating slot antenna elements. The research results of the invention are as follows: the antenna operates in the Ka band frequency range; the realized gain at the center frequency is 34.2 dBi; the sidelobe level of the sum beam on the two E and H planes is less than −25 dB; the difference between the two peaks of the beams on the difference beam is small (about 0.1 dB); the peak-null difference of the difference beam is greater than 43 dB.

The invention discloses a preparation method and application of a polyimide / aminated graphene oxide (PI / AGO) composite wave-absorbing film. The method comprises the following steps: preparing aminated graphene oxide (AGO) by grafting p-phenylenediamine to graphene oxide; the preparation method comprises the following steps: dispersing AGO in N, N-dimethylacetamide in an inert atmosphere, and carrying out low-temperature polycondensation on the N, N-dimethylacetamide, 4, 4 '-diaminodiphenyl ether and 3, 3', 4, 4 '-benzophenone tetracarboxylic dianhydride to prepare a polyamide acid / AGO solution; the composite film is obtained through film casting and stepped thermal imidization (150-300 DEG C gradient heating). The innovation lies in that AGO amino groups are bonded with polyimide monomers, nanoscale dispersion (the content is 1.6-2.8 wt%) is achieved, and the problems of high-temperature oxidation and interface defects of traditional filler are solved. The obtained film shows remarkable wave absorbing performance in a Ka wave band (26.5-40GHz), and is suitable for the fields of electromagnetic protection of high-frequency electronic equipment and radar stealth.

Provided is a 10W power amplifier for Ka band. The power amplifier includes, a drive amplifier; an intermediate stage amplifier composed of two transistors; a final stage amplifier composed of 4 transistors; a GCPW, waveguide, and a first spatial combiner unit which are sequentially connected between the drive amplifier and the intermediate stage amplifier to divide a signal output from the drive amplifier and provide the divided signal to the intermediate stage amplifier; a second spatial combiner unit, a waveguide divider, and a third spatial combiner unit which are sequentially connected between the intermediate stage amplifier and the final stage amplifier to divide signals output from the intermediate stage amplifier and provide the divided signals to the final stage amplifier; and a fourth spatial combiner unit and a waveguide combiner which are sequentially connected to the output terminal of the final stage amplifier to combine signals output from the final stage amplifier and finally output the combined signals.

The invention relates to a preparation method and application of a polyimide / sulfur-doped aminated graphene (PI / S-AGO) composite wave-absorbing film. The preparation method is realized by three steps of: firstly, bonding graphene oxide with p-phenylenediamine to prepare aminated graphene (AGO); then enabling AGO to react with sodium polysulfide at 95 DEG C, and embedding sulfur atoms into graphene crystal lattices in a C-S bond form to form sulfur-doped graphene (S-AGO); finally, the S-AGO, 4, 4 '-diaminodiphenyl ether and 3, 3', 4, 4 '-benzophenone tetracarboxylic dianhydride are subjected to low-temperature polycondensation and gradient imidization (150-300 DEG C), and the composite film is prepared. The innovation lies in that lattice defects and polar functional groups introduced by sulfur doping significantly enhance the interface / dipole polarization effect, so that the reflection loss of the material at the Ka waveband (26.5-40 GHz) and 34.8 GHz reaches-65.8 dB, the effective absorption bandwidth is 6.42 GHz (the corresponding thickness is 3.15 mm), the performance is improved by 61% compared with that of an undoped system, and the material is suitable for the fields of 5G communication (28 / 39 GHz), radar stealth and high-frequency electromagnetic shielding.

The present invention discloses a method for quickly testing the directional pattern of a phased array antenna based on the segment function of a vector network. The system can quickly measure the directional pattern indicators of phased array antennas in the L, S, C, X, Ku, K, and Ka bands, thereby providing relevant evidence for the research and debugging of phased array antennas. The present invention includes modules such as a test turntable, a phased array antenna test fixture, a vector network analyzer, a feed turntable, a standard gain antenna, a radio frequency matrix switch, a timing controller, a computer, and a programmable power supply. During the process of the turntable moving at a constant speed from the starting position to the stop position, the turntable continuously reports the current position; after detecting that the trigger position has been reached, the timing controller automatically controls the phased array antenna to generate a beam and triggers the segment of the vector network to scan and finally complete the directional pattern test.

The invention provides a full-band three-dimensional wave-absorbing metamaterial, which comprises a plurality of basic structure units arranged in a periodic array, and is characterized in that each basic structure unit comprises a first electromagnetic loss three-dimensional superstructure to a sixth electromagnetic loss three-dimensional superstructure and a metal backboard which are sequentially arranged from top to bottom; the first electromagnetic loss three-dimensional superstructure to the sixth electromagnetic loss three-dimensional superstructure are loaded with resistive frequency selective surfaces. The invention has the following beneficial effects: the resistive frequency surface, the pure metal patch and the electromagnetic loss three-dimensional superstructure are combined to carry out multi-dimensional coupling absorption design, so that the full-band absorption performance is realized in the current L, S, C, X, Ku, K and Ka bands with relatively high utilization rate, and certain electromagnetic loss performance is still shown in the V and W bands; the thickness is small, and the maximum oblique incidence angle is not smaller than 70 degrees, so that the requirements of thin-layer and low-surface-density electromagnetic wave-absorbing materials working in the current full-frequency-band range are met.

The invention discloses a single-layer reflective array antenna adopting electric resonance and magnetic resonance units to realize four-beam independent control, which comprises a plane reflective array and a K and Ka dual-band dual-circularly polarized feed source arranged opposite to the plane reflective array, and the plane reflective array consists of a plurality of units consisting of K and Ka band elements which are periodically nested and arranged. The dual-band element structure is designed based on the principles of electric resonance and magnetic resonance, so that the elements of two frequency bands have an extremely weak coupling characteristic, and rapid design of the reflective array antenna is facilitated; meanwhile, each wave band element can realize phase regulation and control through two degrees of freedom of size change and angle rotation, so that independent regulation and control of four circularly polarized wave beam directions on two wave bands are realized. The reflective array antenna is simple in structure, low in cost, easy for engineering realization, and suitable for application scenarios of multi-beam independent regulation and control.

The present invention relates to an improved large reflector-type beamway guide Cassegrain antenna. When the improved large reflector-type beamway guide Cassegrain antenna is applied to an imaging radar, a difference in the radiation pattern of the reflection mirror within the beamway guide occurs when operating a single Cassegrain beamway guide antenna with two frequency bands, one of which is approximately 10 times the wavelength of the low frequency of the L band or S band and the other of the high frequency of the Ku band or Ka band. Therefore, when operating in the low L / S band, the low frequency band mirror of the L / S band and the high frequency band mirror of the Ku / Ka band are duplicated within the beamway guide to make the L / S band and Ku / Ka band efficiencies nearly identical. Here, if the loss in the Ku / Ka band is acceptable, the Ku / Ka frequency band mirror may be omitted. Furthermore, to compensate for gain attenuation caused by deformation of the main reflector due to its own weight as the reflector is large, a main reflector deformation compensation device including an actuator is attached behind the sub-reflector. In the absence of a radome, four panels of the main reflector are automatically adjusted by an ACU for each of the four panel modules. Attach the actuator.

Techniques are described for direct conversion and dynamic polarization control in a very small aperture terminal (VSAT) outdoor unit (ODU). The ODU includes a direct up-converter and / or a direct down-converter for converting in a single stage between a baseband frequency and a satellite radiofrequency band (e.g., Ka band). The ODU also includes a polarization amplifier that integrates high-power amplification with circular polarization orientation control. For example, the direct up-converter directly converts a baseband signal to a low-power satellite-RF transmit signal, and the polarization amplifier converts the low-power satellite-RF transmit signal to an uplink signal having high gain and selected circular polarization. The ODU can further include an integrated embedded computer and modem.

The invention discloses a preparation method and application of a PI / Cu / S-AGO composite wave-absorbing film, through compounding of copper / sulfur co-doped aminated graphene oxide and polyimide, ultra-wideband absorption (EAB is as high as 7.57 GHz and reflection loss is-13.9 dB) of a Ka wave band (26.5-40 GHz) is realized under an industrial practical thickness (1.5 mm), and the dependence of a pure sulfur doping system on an ultra-thin state (less than or equal to 0.94 mm) is broken through; when the thickness is 2.99 mm, the high loss depth (RLmin =-66.2 dB) and the broadband coverage (EAB = 5.39 GHz) are synchronously achieved, and after 400 DEG C treatment, the dielectric loss is only attenuated by 16% (pure sulfur doping is greater than 50%). The preparation method has the innovativeness that 1) copper and sulfur are cooperatively doped, a three-dimensional network of Cu ion anchoring sulfur-doped graphene is formed, and agglomeration (the particle size is smaller than 100 nm) and high-temperature oxidation of copper nanoparticles are inhibited; and 2) a stepped imidization process (150-400 DEG C temperature programming) guarantees the structural stability of the film. The material is suitable for 5G millimeter wave radars, and the defects of insufficient practical thickness bandwidth and poor thermal stability of the existing wave-absorbing film are solved.

The present invention relates to the field of wireless communications technology and discloses a K / Ka-band broadband dual-circularly polarized antenna for low-orbit satellite communications. The key technical aspects of the antenna include: a radiating aperture, a resonant cavity, a dual circular polarizer, a quasi-TEM transmission air cavity layer, a left-polarized broadband feed network layer, a right-polarized broadband feed network layer, a TEM mode conversion terminal, a polarization switch, a transceiver duplexer, a first standard waveguide port layer, and a second standard waveguide port layer. The antenna has a simple structure and self-packaging properties, offering excellent electromagnetic compatibility and high gain, wide bandwidth, and high circular polarization purity. A shielded air cavity is formed by stacking structures and metallized through-holes. When multiple circuits are integrated, mutual interference is minimized, resulting in a compact structure, easy assembly, and excellent electrical performance.

The present invention relates to a dual-channel signal source, belonging to the technical field of microwave signal sources, and solves the problem that the frequency bands of existing microwave signal sources do not exceed two and the use of two 4U signal sources leads to an increase in test costs and volume. The signal source includes: a frequency synthesizer module that provides a broadband local oscillator signal and a frequency-agile local oscillator signal; a down-conversion module that mixes the received X, Ku, and Ka band signals with the local oscillator signal and then mixes the mixing result with the frequency-agile local oscillator signal to generate two intermediate frequency signals; a real-time control module that outputs two DDS signals to the frequency synthesizer module according to two frequency measurement signals; an intermediate frequency processing module that delays and forwards the two input intermediate frequency signals; an up-conversion module that up-converts the two delayed variable intermediate frequency signals to two X, Ku, and Ka band output signals; and two channel radio frequency output modules that output the two X, Ku, and Ka band output signals via channel A and channel B respectively. Two-channel X, Ku, and Ka signal sources that work independently are integrated in a single chassis.

The application discloses a K / Ka-band circularly polarized transceiving common-aperture phased array antenna and phased array, comprising: a multilayer stacked substrate structure, the substrate comprising a metal layer, a dielectric layer and an adhesive layer; a K-band array element comprising a K-band radiation patch arranged on part of the metal layer, a K-band feeding structure and a K-band filtering structure, the K-band filtering structure comprising a first filtering structure, a second filtering structure and a third filtering structure; a Ka-band array element comprising a Ka-band parasitic patch arranged on part of the metal layer, a Ka-band radiation patch and a Ka-band filtering structure; each common-aperture phased array antenna comprises one K-band array element and five Ka-band array elements. The common-aperture antenna provided by the application can meet the requirement of realizing a conical surface wide-angle scanning in the K / Ka-band, and meanwhile, the problems of poor common-aperture antenna same-frequency and different-frequency isolation and poor circularly polarized array scanning axial ratio performance are overcome.