111 results about "Relative bandwidth" patented technology

The invention belongs to the technical field of antenna engineering, and particularly relates to an ultra-wide-band low-profile phased-array antenna, which realizes broadband impedance matching characteristics and effectively expands the working bandwidth of the antenna by optimizing a dipole arm structure and introducing a matching branch knot and linear tapered slot composite structure on a radiation unit layer; on the array architecture level, an electromagnetic metasurface technology is adopted, array current distribution is improved through a periodic artificial electromagnetic structure, the active standing-wave ratio is remarkably reduced, the scanning angle of an array is widened, and meanwhile high compression of a system profile is achieved; on the structural design level, a three-dimensional composite structure of a transverse metal floor, a longitudinal radiation layer and a transverse metasurface layer is innovatively constructed, and the overall section height is reduced to 0.137 lambda Low (lambda Low is the lowest working frequency wavelength) through electromagnetic coupling and space folding technologies; in conclusion, the ultra wide band (the relative bandwidth is greater than or equal to 90%) and the low profile (lt; and the method is suitable for a new generation of broadband phased array radar system.

The invention discloses an ultra-wideband 180-degree phase shift circuit which comprises a radio frequency signal input end, a radio frequency signal output end, an ultra-wideband balun with a center tap and a stub compensation line, a first matching compensation network, a second matching compensation network, a differential signal switch selection circuit and a control circuit. The ultra-wideband balun can realize conversion between a single-ended signal and a differential signal in an ultra-wideband frequency range, a first differential output port of the ultra-wideband balun is connected with one end of the first compensation matching network, and a second differential output port of the ultra-wideband balun is connected with one end of the second compensation matching network; a first differential port of the differential signal switch selection circuit is connected with the other end of the first compensation matching network, and a second differential port of the differential signal switch selection circuit is connected with the other end of the second compensation matching network; and the control circuit is used for controlling the differential signal switch selection circuit to switch and output 0-degree and 180-degree radio frequency signals. According to the invention, low-error phase shift precision can be provided within the frequency range of 2-20GHz and the relative bandwidth of 160%.

The present invention relates to the fields of ferroelectric single crystal technology and acousto-optical device technology, particularly to a silicon-based lead magnesium niobate (PbMn) single crystal piezoelectric wafer structure, preparation method, and application. The structure comprises a silicon substrate on which a silicon dioxide layer and a single crystal piezoelectric thin film layer are sequentially disposed; the single crystal piezoelectric thin film layer is a PbMn-PT single crystal, including a binary PMN-PT single crystal thin film or a ternary PIN-PMN-PT single crystal thin film. This piezoelectric wafer structure on a silicon substrate can be used to fabricate various high-performance piezoelectric MEMS sensors, actuators, and electro-optical modulator devices. The resulting surface acoustic wave (SAW) filters and thin film bulk acoustic wave (BAW) filters exhibit a relative bandwidth increase of over 50%, and the resulting electro-optical modulators exhibit lower half-wave voltage and higher electro-optical modulation efficiency. The device volume can be reduced by 10 times, better meeting the future 6G communication requirements for higher efficiency, higher integration, and miniaturization of MEMS devices. This provides a novel multilayer piezoelectric wafer structure for the miniaturization and integration of piezoelectric MEMS and optoelectronic devices.

The invention belongs to the field of electromagnetic wave absorbing materials, and particularly relates to a thin broadband composite wave absorber based on a frequency selective surface. According to the invention, the wave-transparent layer is added in the middle of the multi-layer magnetic material, the mindset of simply stacking the same type of materials in the traditional multi-layer wave-absorbing structure is broken, and the wave-transparent layer is introduced to change the original characteristic that the impedance gradually changes in sequence; meanwhile, a magnetic wave-absorbing material, a frequency selection surface and a medium matching layer are subjected to composite design, the frequency selection surface generates an electromagnetic coupling effect at high frequency, phase and impedance conversion of electromagnetic waves in a multi-layer structure is controlled, and efficient impedance matching and electromagnetic wave energy dissipation in a broadband are achieved through electromagnetic absorption and interference cancellation; and an excellent wave absorbing effect is achieved. The total thickness of the composite wave absorber ranges from 0.064 lambda to 0.1 lambda, the-10 dB absorption bandwidth ranges from 3.3 GHz to 18 GHz, and the relative bandwidth reaches 138%; and meanwhile, the wave absorber has a wide angular domain characteristic under oblique incidence, and a novel thin broadband composite wave absorber scheme is provided.

The application claims a kind of multiband terahertz absorber based on laminated graphene structure, which is a laminated stack structure.The positive terminal of external power supply is connected to two layers of graphene, and the negative terminal is connected to a gold reflection layer.The Fermi energy level of graphene is controlled by voltage.The structure parameters of each layer, graphene and dielectric layer material characteristics are set.The absorber forms multiple absorption peaks in the 1~5 THz frequency band, with a peak absorption rate of over 90%.At 1.60 THz, a narrowband absorption of 93% is achieved, and at 2.54~4.28 THz, a broadband absorption with a relative bandwidth of 51% is achieved.The normalized equivalent impedance at the resonance frequency point is nearly perfectly matched with the free space impedance.The absorber also has good polarization angle insensitivity, with only slight absorption performance attenuation within an incident angle range of 0~60°.The absorption characteristics can also be adjusted by adjusting the key geometric parameters.The application can simultaneously achieve narrowband and broadband absorption, with excellent absorption performance, and is suitable for interference signal filtering in terahertz communication systems.

The disclosed technology provides a system and method for allocating frequency bands to a mobile device or user equipment (UE) based on priorities assigned to the different frequency bands. When no priority is assigned to the frequency bands, when a special or reserved priority is assigned, or when equal priority is assigned, the frequency band allocation to the UE is based on a default frequency allocation algorithm (e.g., based on a relative bandwidth of the different frequency bands). When a UE is capable of utilizing a first and a second frequency band, and the priority assigned to the first frequency band is higher than the priority assigned to the second frequency band, the network (e.g., eNB / gNB) overrides the default algorithm and preferentially allocates the first frequency band to UE even when the first frequency band has a smaller bandwidth than the second frequency band or when the default algorithm would otherwise prefer the first frequency band.

The invention provides a data scheduling method and system and switch equipment. The method comprises the following steps: initializing queue configuration information of data scheduling in a data center switch; extracting a relative bandwidth proportion of each data queue in the data center switch from the queue configuration information, and determining a relative quantum feature of each data queue through each relative bandwidth proportion; performing quota resetting on deficit counters of the data queues based on the relative quantum features of the data queues, determining the amount of data capable of being sent of the data queues through the deficit counters with the reset quota and the current data packet length of the data queues, and further updating the queue states of the data queues; and generating a next round of scheduling polling queue in the data center switch based on all queue states, and performing deficit polling scheduling on the data queues in the data center switch through the scheduling polling queue. Based on the scheme, cooperative scheduling of dynamic weight allocation and accurate deficit management in the switch can be realized, so that the bandwidth utilization rate of the switch can be improved.

The application discloses a dual-polarized microstrip patch antenna applied to a millimeter wave phased array, and belongs to the field of radio frequency front ends.The antenna mainly comprises two substrates and two patch structures, wherein the top patch is fed by two coaxial probes, the feeding port has two feeding slits, and the bottom patch is in a cross shape, which increases the cross-polarization ratio of the dual-polarized antenna radiation.The antenna realizes the dual-polarized characteristic at H plane + / -45 DEG, the 10dB relative bandwidth is 38.9%, and the radiation pattern half-power beam width is greater than 100 DEG. The antenna has the characteristics of simple structure and simple manufacturing, and can be rapidly printed and manufactured by adopting a planar microstrip structure.

According to the magnetoelectric dipole antenna, the coaxial feed communication bandwidth is larger than 100%, and the technical problems that broadband impedance matching and high-frequency mismatching are achieved, and the stability of a feed structure is poor are solved. According to the antenna, a meandering seam bending type electric dipole and a stepped flaring type magnetic dipole are cooperatively matched, and a feed structure and a U-shaped reflector are combined to integrally form the magnetoelectric dipole antenna. A meandering seam is etched on a horizontal rectangular patch, a vertical patch is welded on the outer side of the horizontal rectangular patch to form a three-dimensional radiator, and the three-dimensional radiator and a stepped flaring type cavity structure magnetic dipole form a closed structure. The feed structure comprises a coaxial line and two bent copper sheets, thereby realizing direct current grounding and providing mechanical reinforcement. 3.7 GHz and 4.2 GHz resonance points are introduced to realize 104.8% of relative bandwidth, while the compact structure is maintained, the broadband coverage and stable radiation characteristics are realized, the long-term reliability in an outdoor complex environment is ensured by a stable feed structure, part of 5G communication signals in a Sub-6G frequency band can be effectively covered, and the antenna is suitable for various wireless communication systems.

The application belongs to the technical field of wireless communication, and relates to the structural design of a broadband antenna, and specifically provides a low-profile broadband dual-polarized metasurface antenna which is composed of a microstrip feed network 5, a lower layer dielectric substrate 4, a metal floor 3, an upper layer dielectric substrate 2 and a metasurface radiation array 1 which are sequentially stacked from bottom to top. The structure of the metasurface radiation array is creatively designed through eigenmode analysis, so that the strongest current is regulated to the central rectangular patch, thereby enabling the microstrip feed structure to excite vertical and horizontal polarization radiation modes through the cross-shaped slot on the metal floor, realizing the dual-polarization and broadband characteristics of the antenna. Finally, the bandwidths of the two ports of the antenna cover 3.42-6.09 GHz and 3.56-6.24 GHz respectively, the relative bandwidths are 56.15% and 54.69% respectively, the maximum gains of the two ports in the passband can reach 10.4 dBi and 11.0 dBi respectively, and the profile height is only 0.085λ0. Moreover, the application has the advantages of simple structure, wide bandwidth, low profile, low processing and assembling difficulty and the like.

The 6G satellite communication terminal system comprises a grounding layer, a substrate layer, a feed layer and a radiation metal patch, the grounding layer is arranged at the lower end of the substrate layer, the feed layer is arranged at the upper end of the substrate layer, the radiation metal patch is of a square structure, and the radiation metal patch is arranged on the substrate layer. The radiation metal patches are arranged at the upper end of the feed layer in a matrix mode, cross-shaped gaps are etched in the upper end walls of the radiation metal patches, the radiation metal patches and the feed layer are electromagnetically coupled through the cross-shaped gaps, and the feed layer is provided with a T-shaped strip line matching network. According to the technical scheme of the invention, the electromagnetic decoupling of the Ku / Ka dual-frequency transceiving coplanar phased array can be realized (the isolation degree gt; 45 dB), and a broadband impedance modulation type power amplification technology (24-30 GHz relative bandwidth gt; 25%), a multilayer microwave composite board integrated framework (the thickness is lt; 2 mm, the interconnection loss lt; therefore, the requirement for light weight is met, scanning at a wide angle of + / -60 degrees is supported, and the consistency of a directional diagram of the antenna is also improved.

The utility model discloses a full-wave oscillator unit and an antenna. The full-wave oscillator unit comprises a bottom plate, an oscillator support and an antenna radiation oscillator, the antenna radiation oscillator is arranged on the front surface of the bottom plate, the antenna radiation oscillator and the bottom plate are arranged in parallel up and down, and the antenna radiation oscillator is supported by the oscillator support on the bottom plate; wherein two oscillator arms in the 45-degree direction and the-45-degree direction of the antenna radiation oscillator form a crisscross dual-polarized radiation unit. The antenna provided by the utility model has the characteristics of high gain, low cost and simple structure. The antenna mainly covers a relatively wide working frequency band of 698MHZ-960MHZ, and the relative bandwidth reaches 32%; the radiation gain of 9-10db is realized by the unit oscillators; a plurality of unit oscillators form an array antenna to realize broadband and high gain performance; through printed board processing, the size consistency is improved; the assembly structure is simple, and production efficiency is improved.

The utility model discloses a microstrip patch antenna which comprises a dielectric substrate and a radiation patch. The radiation patch is arranged on the dielectric substrate, the radiation patch is E-shaped, the parallel edge of the E-shaped radiation patch is defined as a first sub-radiation patch, the vertical edge of the E-shaped radiation patch is defined as a second sub-radiation patch, and the length of the first sub-radiation patch is larger than or equal to 2.1 mm and smaller than or equal to 2.5 mm. The E-shaped structure enables the current to bypass between the first sub radiation patch and the second sub radiation patch, which is equivalent to increasing the electrical length of the radiation patch and reducing the resonant frequency of a fundamental mode, so that the low-frequency band bandwidth is broadened; the edges of the first sub-radiation patch and the second sub-radiation patch can generate strong electromagnetic field coupling to excite an additional parasitic resonance mode, so that the frequency band is further widened, and the bandwidth of the microstrip patch antenna is effectively widened. Wherein the first sub radiation patch of 2.1 mm to 2.5 mm enables the resonant frequency of the microstrip patch antenna to range from 43.7 Ghz to 55.1 Ghz, the relative bandwidth is 23%, and high bandwidth is achieved.

This invention discloses a bandpass frequency-selective surface structure based on strongly coupled pairs, composed of multiple basic structural units. Each basic structural unit has a vertically symmetrical structure along its thickness direction. Both the upper and lower symmetrical portions include a first metal layer and a first dielectric layer in symmetrical positions. The first metal layer contains a first resonator pair, a second resonator pair, and a third resonator pair, each using metal patches as resonators. A second metal layer and a second dielectric layer, separated along the thickness direction of the basic structural unit and in asymmetrical positions, are disposed between the upper and lower symmetrical portions. The upper and lower symmetrical portions are connected by metal conductive posts. This invention operates stably at a center frequency of 5 GHz, introduces four transmission zeros, achieves a fourth-order frequency response within 8.4% of the relative bandwidth, has an insertion loss of less than 0.49 dB, and 40° angular stability, exhibiting superior performance.

The invention relates to the technical field of communication equipment, and discloses a frequency hopping filter with a hopping transmission zero point, a hopping control method and communication equipment. At least one resonant inductor of an LC resonant circuit of the frequency hopping filter is connected with a radio frequency switch feedback capacitor array in parallel; the frequency of a transmission zero point at a higher harmonic of the frequency hopping filter is controlled by controlling the opening and closing of a channel where each feedback capacitor in the radio frequency switch feedback capacitor array is located, so that the frequency of the transmission zero point changes along with the center frequency of the frequency hopping filter; and finally, far-end suppression, relative bandwidth stability and frequency hopping accuracy in a wide frequency range are improved.

The application relates to a kind of foldable band-pass filters based on polyimide flexible substrate.The filter adopts coplanar waveguide structure, and is prepared using self-assembly technology.It is tested that the filter center frequency is 2.5 GHz, the relative bandwidth is 15.9%, the minimum insertion loss is 0.71 dB, and the in-band return loss is greater than 20 dB.The performance of the filter is basically consistent in flat, curved and folded states.The flexible filter prepared using the self-assembly technology is expected to become one of the components of future flexible communication systems.

The utility model discloses a dual-frequency circularly polarized combined antenna, which comprises a metal reflecting plate, a high-frequency circularly polarized radiation unit and a low-frequency wide-beam radiation unit, the high-frequency circularly polarized radiation unit and the low-frequency wide-beam radiation unit share the same reflecting plate, and the high-frequency circularly polarized radiation unit is positioned above the low-frequency wide-beam radiation unit. According to the utility model, the embedded orthogonal dipole pair is adopted, so that the high-frequency-band axial ratio bandwidth breaks through the limitation of the traditional single-feed microstrip antenna, the relative bandwidth with the actually measured axial ratio less than or equal to 3dB reaches 18.7%, and the Beidou third-generation B1C / B2a frequency band requirement can be completely covered. The nickel-chromium alloy films evaporated on the upper and lower surfaces of the dielectric plate effectively inhibit interlayer crosstalk, the cross polarization ratio is improved to be greater than 15dB, and the dual-band radiation purity is ensured.

The invention discloses a millimeter wave ultra-wideband substrate integrated coaxial line antenna array based on a laminated metasurface. The ultra-wideband antenna array comprises a coplanar waveguide-to-substrate integrated coaxial line switching structure, a one-to-eight power divider based on a substrate integrated coaxial line structure, a butterfly coupling slot and a laminated metasurface antenna, after being fed in by the coplanar waveguide, energy is transmitted to the substrate integrated coaxial line power divider through the blind hole structure, and is uniformly distributed to eight channels in the substrate integrated coaxial line power divider; and then, the energy is coupled and fed to the laminated metasurface antenna through the coupling slot. The antenna can stably work in the frequency range of 15.84 GHz-49.15 GHz, the return loss (S11) is always lower than 10 dB, and the corresponding relative bandwidth is 102.5%. In a target working frequency band, the maximum peak gain of the antenna can reach 18.58 dBi, and the antenna has excellent ultra-wideband characteristics and good radiation performance.

The application discloses an ultra-wideband polarization converter metasurface for converging lenses and spatial imaging. The cell of the metasurface is composed of two metal gratings, two pairs of L-shaped metal patches and two dielectric plates. The metasurface of the application works in the range of 0.5 to 1.8 THz, the transmission coefficient is greater than 0.87, the relative bandwidth reaches 113%, the polarization conversion rate remains close to 100%, and the phase covers 360°. The metasurface has the advantages of simple structure, small size, high bandwidth, good polarization characteristics, easy integration, low loss and simple preparation process. The metasurface combines the changes of geometric phase and amplitude, which can not only realize two-dimensional focusing lenses by using phase changes, but also realize spatial imaging functions by using amplitude changes. The research results show that the metasurface provides a new way for the flexibility of terahertz wave polarization and phase manipulation, and opens up a new way for the dynamic operation of terahertz wave fronts.

The invention discloses an inclined beam circularly polarized antenna array for an X-band airborne SAR (Synthetic Aperture Radar). The inclined beam circularly polarized antenna array comprises a cylindrical dielectric resonator antenna array, a T-shaped slotted floor, a dielectric substrate, an equal phase shift feed network and a grid type metal plate. The antenna array works in a wide frequency band, the relative bandwidth of about 10% is realized in an X wave band, and meanwhile, the requirement of S11lt is met; the impedance matching sum ARlt is-10dB; the axial ratio performance is 3dB; meanwhile, the antenna array realizes stable high gain performance in an X wave band, and the right-handed circular polarization gain full wave band is more than 10dBic; in addition, by arranging the feed network, the antenna array beam can be inclined within the range of 30-35 degrees, and good right-handed circular polarization purity is kept, so that the beam inclination can be realized by horizontally installing the antenna, and the low profile of the airborne SAR system is realized.

The utility model relates to the technical field of terahertz radio frequency circuits, solves the technical problems of narrow relative bandwidth and complex processing of a terahertz frequency band waveguide duplexer, and particularly relates to a terahertz multistage coupling type duplexer easy to realize by CNC (computer numerical control). Comprising a duplexer main body structure which is formed by separably combining an E-plane slotted waveguide structural body A and an E-plane slotted waveguide structural body B. The duplexer main body structure is formed by cascading an E-plane Y-type junction with two filters and is provided with an input waveguide, a low-frequency output waveguide and a high-frequency output waveguide. Compared with a traditional T-shaped junction, the T-shaped junction is more suitable for the design of a broadband waveguide duplexer, and the compactness and simplicity of the structure are kept. Actual measurement shows that 24% of total working bandwidth is obtained, and the overall performance of a terahertz communication system is further improved.

This invention discloses a nested ferrite switch based on a composite magnetic circuit, belonging to the field of microwave device technology. It includes a central ferrite rod (1), an insulating dielectric sleeve (2), an excitation coil (3), and a dielectric substrate (5). A coplanar waveguide transmission line (6) is provided on the dielectric substrate (5). The central ferrite rod (1) is embedded in the central junction of the coplanar waveguide. A soft magnetic metal yoke (4) with a magnetic flux density of 2 to 5 times the saturation magnetization of the ferrite is provided outside the central ferrite rod (1). This invention uses a coplanar waveguide and a special magnetic yoke design for the ferrite switch, which can achieve the advantages of high power capacity and wide bandwidth. Through simulation design, the relative bandwidth of the ferrite switch designed with this structure can reach more than 15%.

The invention discloses a high-temperature superconducting band-pass filter design method and system, a storage medium and equipment. The method comprises the following steps: firstly, determining design indexes including center frequency, relative bandwidth and the like and an extensible structure framework formed by cascading a plurality of coupling lines and more than one branch line; respectively establishing a differential-mode equivalent circuit model and a common-mode equivalent circuit model of the filter according to a transmission line theory; then constructing a multilayer perceptron type circuit-level physical information neural network model with residual connection, inputting design indexes into the model, and embedding an equivalent circuit matrix and a target differential mode transmission function into a loss function to complete training; and outputting coupling line even-mode and odd-mode characteristic impedance and branch line characteristic impedance through the trained model, and generating a filter physical layout according to the output coupling line even-mode and odd-mode characteristic impedance and the branch line characteristic impedance. The method fuses the physical information neural network, can quickly generate the superconductive filter layout, and effectively improves the design efficiency and prediction precision.

The invention relates to a minimum relative bandwidth microwave receiving device and method. The device comprises an atomic narrowband frequency hopping communication receiving subsystem and a high-power narrowband frequency hopping communication signal transmitting subsystem. The atomic narrowband frequency hopping communication receiving subsystem is used for receiving and demodulating narrowband frequency hopping communication signals; the high-power narrowband frequency hopping communication signal transmitting subsystem is used for transmitting high-power narrowband frequency hopping communication signals; the atom narrowband frequency hopping communication receiving subsystem comprises a Rydberg atom preparation module, a three-wavelength ultra-stable laser integrated device, a communication signal broadband receiving antenna and a communication signal demodulation module; the high-power narrowband frequency hopping communication signal emission subsystem comprises a millimeter wave high-power emission source, a communication signal broadband emission antenna and a communication signal modulation module. According to the invention, the response characteristic of extremely small relative bandwidth of Rydberg atoms is utilized, out-of-band noise signals introduced into a receiving system are reduced, the detection signal-to-noise ratio of a microwave communication receiving system is improved, and the anti-interference capability of microwave communication in a complex environment is improved.

The invention provides a terahertz functional device based on a silicon-based all-dielectric, and belongs to the field of terahertz communication. The device aims to realize efficient electromagnetic wave active radiation through a controllable leaky-wave mechanism, so that the terahertz device is called a leaky-wave antenna for short. The device is composed of a photonic crystal waveguide, a periodic radiation structure and a radiation suppression layer. The overall structure is designed based on the hexagonal lattice photonic crystal, and electromagnetic wave energy can be effectively bound in the waveguide transmission line. A periodic groove is etched above a waveguide transmission line, so that energy transmitted by a waveguide is radiated to a free space at a specific angle, and a directional radiation wave beam is formed. The effective radiation frequency band of the leaky-wave antenna is a terahertz frequency band, the relative bandwidth can reach 22%, and the leaky-wave antenna belongs to a broadband radiation device. The antenna has the advantages of being small in size and capable of achieving wide-angle beam scanning and ultra-wideband detection, the beam scanning function of the antenna can be used for achieving dynamic beam forming, the reliability of a communication link and the data transmission rate can be improved, and the antenna is suitable for various application scenes such as space optical communication and biological sensing scanning.

The application discloses a band-pass filter, and relates to the field of microwave technology.The band-pass filter comprises a first shielding layer, a resonant coupling layer and a second shielding layer which are sequentially arranged from top to bottom and are made of a low-temperature co-fired ceramic process.The resonant coupling layer comprises a first coupling line, a second coupling line, four resonators arranged from left to right and three couplers;one coupler is arranged between every two adjacent resonators;the first coupling line is located above the resonators at the leftmost end and the rightmost end;the second coupling line is located below the two resonators in the middle;the resonators and the couplers are connected with ground ports;the resonator at the leftmost end is connected with an input port;the resonator at the rightmost end is connected with an output port;the first shielding layer and the second shielding layer are connected with the ground ports.The application can make the relative bandwidth of the passband less than 10%, and improve the passband performance and the stopband suppression performance.

The invention discloses an ultrasonic endoscope transducer based on a lead-free piezoelectric ceramic material as well as a preparation method and application of the ultrasonic endoscope transducer. The ultrasonic transducer comprises an acoustic backing layer, a lead-free piezoelectric layer, an acoustic matching layer and a coaxial wire, the lead-free piezoelectric layer is made of lead-free piezoelectric ceramic or a lead-free piezoelectric ceramic composite material; according to the method, the matching layer is prepared by adopting a spin-coating method, so that the method has huge advantages in preparation of a micron-sized matching layer, and a new way is provided for preparation of the matching layer of the high-frequency ultrasonic transducer. A gradient matching material is used as an acoustic matching layer, and materials with low, medium and high acoustic impedances are prepared as the gradient acoustic matching layer, so that the sensitivity and the bandwidth can be effectively improved, and the performance of the transducer is improved; the lead-free piezoelectric ceramic and the lead-free piezoelectric ceramic composite material used for preparing the piezoelectric layer of the ultrasonic transducer have the advantages of being thin in thickness, high in dielectric constant, high in piezoelectric coefficient and the like, the amplitude is high, the sensitivity is high, the relative bandwidth is large, and the imaging effect of an ultrasonic endoscope system is greatly improved.

The invention discloses a terahertz three-dimensional link interconnection-oriented bistable adjustable pseudo surface plasmon waveguide and a preparation method thereof, and belongs to the technical field of terahertz on-chip communication, the waveguide comprises a feed structure, an actuator, a patterned metal patch, a flexible dielectric substrate and a fiber-reinforced active layer, wherein the fiber-reinforced active layer is provided with a positive thermal response area and a negative thermal response area, S-shaped bending can be generated under photo-thermal excitation, and dynamic switchable interconnection between chips with different heights in a three-dimensional space is achieved. The working frequency band of the waveguide is 31.56-127.71 GHz, the relative bandwidth reaches 120%, the insertion loss is lower than 1.5 dB, and the waveguide has the characteristics of low loss, ultra wide band and bistable holding. The preparation method comprises the steps of waveguide main body structure processing, fiber reinforced active layer compounding, actuator integration and overall assembly. The method solves the problems that the existing terahertz interconnection dimension is limited and the resource allocation is fixed, and is suitable for a high-density three-dimensional integrated and dynamic reconfigurable system on chip.

The invention belongs to the technical field of wireless communication, and discloses a broadband circularly polarized wide-angle beam scanning antenna device based on a truncated Luneberg lens. Comprising a truncated Luneberg lens and an equiangular-Archimedes composite spiral feed source, the feed source adopts an equiangular spiral antenna at a high frequency and adopts an Archimedes spiral antenna at a low frequency, and 80% of relative bandwidth and good circular polarization characteristics are realized. The truncated luneberg lens is manufactured through a 3D printing process and is adaptive to a frequency band of 1.5-3.5 GHz, the truncated depth is 0.6 times of the radius to form a flat focal plane, and the refractive index gradient is 1.17-2.77. The flat focal plane is designed based on the Hamiltonian optical theory and supports feed source linear displacement to achieve + / -43-degree circular polarization wide-angle beam scanning. And the refractive index change is realized by the metamaterial structure units filled with the photosensitive resin by air in a layering manner. According to the invention, Hamiltonian optics, 3D printing and composite helical antenna technologies are integrated, and the antenna has broadband characteristics, high gain, low gain fluctuation and wide-angle scanning capability, and is suitable for various broadband wave beam scanning scenes.

The invention, which relates to the technical field of the phased-array antenna, discloses a low-profile integrated broadband wide-scanning phased-array antenna unit comprising a microwave multilayer dielectric plate, a radiation patch, a dual-polarization feeder line and a correction line. The four radiation patches are arranged on the upper surface of the first dielectric plate, and the four radiation patches are symmetrically distributed about the geometric center of the antenna unit; the dual-polarization feeder line comprises a horizontal polarization feeder line and a vertical polarization feeder line, the horizontal polarization feeder line is arranged in the middle of the upper surface of the first dielectric plate, the vertical polarization feeder line is arranged in the middle of the upper surface of the second dielectric plate, and the direction of the horizontal polarization feeder line is perpendicular to that of the vertical polarization feeder line; the antenna unit and correction network is low in overall profile height, about 0.16 lambda0 (lambda0 is the central frequency wavelength), compact in structure, easy to process and suitable for tile type array application, has the relative bandwidth not less than 30%, can meet the two-dimensional phase scanning requirements of azimuth and pitching + / -45 degrees, and has the polarization isolation degree superior to 20 dB.