42results about How to "Overcoming Bandwidth Limitations" patented technology

The invention discloses a safe communication method between nodes in a vehicular network. The method provides a disperse trust and security system based on elliptic curves. Before communicating, communication nodes are two-way indentified by a (t, n) threshold authentication proposal to prevent hostile nodes from personating legal nodes and t-1 members in a network from counterfeiting certificates. Meanwhile, a key exchange based on password authentication is carried out to ensure that all conventioneers consult about a key by a safe approach, and therefore, a strong session key is generated to provide message discrimination, confidentiality and integrality for communication nodes in a vehicular network. The method of the invention adopts an elliptic curve encryption scheme and the (t, n) threshold authentication proposal, thereby being characterized by small calculated amount, low complexity, high safety, small key space, high speed, needing no authentic certificate authority and having great application value in vehicular networks.

The invention discloses a flexible capacitor type micromachining ultrasonic transducer (CMUT). The flexible CMUT comprises a flexible substrate, a lower electrode, an etching sacrificial layer, an organic polymer support layer, an organic polymer vibration thin film and an upper electrode which are arranged sequentially. The organic polymer support layer is provided with a groove, and the groove and the organic polymer vibration thin film form a cavity of the ultrasonic transducer. The invention further discloses a preparation method of the flexible CMUT. According to the flexible CMUT, ultrasonic loss caused by poor coupling is effectively reduced, and the flexible ultrasonic transducer is achieved. The flexible CMUT is suitable for detection objects, including animals' epidermal tissue, of any shapes, so that the application range of the CMUT is effectively widened. The preparation method is simple in preparation process and low in cost.

The invention discloses a device for optically generating radar pulse compression signals. The device comprises a laser, a coding signal generator, a microwave signal generator, a polarization multiplexing double-parallel Mach-Zehnder modulator, a direct-current power supply, a photoelectric detector, a polarizer and a polarization controller; and, by utilization of the frequency-shifting characteristic and the phase modulation characteristic of the polarization multiplexing double-parallel Mach-Zehnder modulator, after being coupled through the polarizer, polarization orthogonal modulated optical carrier signals and unmodulated optical first-order sideband signals output by the polarization multiplexing double-parallel Mach-Zehnder modulator are detected through the photoelectric detector, so that phase coded or linearly frequency-modulated radar pulse compression signals can be generated. On the basis of the integrated modulator structure, the device disclosed by the invention is simple in system composition and steady in performance; and, the following disadvantages can be overcome: the traditional manner of generating pulse compression signals in the electric domain is limited by the rate and the bandwidth of an electronic device; high-frequency signals are generated difficultly or cannot be generated; the time-bandwidth product is limited; the reconfigurability and the frequency adjustability of the system are poor, etc.

The invention relates to a direct current / direct current converter and a direct current / direct current converting method, which belong to the technical field of microelectronics and power management. The direct / direct current converter provided by the invention reduces hardware expenditure and power consumption on the premise of meeting the requirements of a high frequency (HF) switch. The direct current / direct current converter comprises a current detecting module, an oscillator, an error amplifier, a comparator and a logic circuit, wherein the current detecting module is used for generating a current detecting signal; the oscillator is used for performing superposition compensation on the current detecting signal; the error amplifier is used for comparing feedback voltage with band gap reference voltage to obtain an error amplifying signal; the comparator is used for comparing the compensated current detecting signal with the error amplifying signal to generate a pulse width modulation signal; and the logic circuit is used for generating a control signal for controlling a power switch. Compared with traditional structure, the direct current / direct current converter has the advantages of reducing complexity, reducing function consumption, improving performance, reducing cost due to smaller chip area, and improving product competitiveness of a direct current / direct current conversion chip.

The invention relates to a data acquisition and processing device and method. Through the FPGA, the storage controller and the memory, collection of external information is realized, and through the processor, analysis and operation processing of the external information are realized. While the processor reads the data from the memory, the FPGA continues to collect external information, and the acquired data is transmitted to the memory in real time, so that the data acquisition and processing device is overlapped in data processing and data acquisition time. The data transmission efficiency in the data acquisition and processing device is greatly improved, and the data processing capability of the data acquisition and processing device is further improved.

The invention provides a data backup method and device. The method comprises the following steps: receiving a backup message; judging whether a service board corresponding to a target service board identification carried by the backup message is on home terminal frame type equipment; if the service board corresponding to the target service board identification carried by the backup message is on the home terminal frame type equipment, sending the backup message to the service board corresponding to the target service board identification to enable the service board to store backup data carried in the backup message; and if the service board corresponding to the target service board identification carried by the backup message is not on the home terminal frame type equipment, determining opposite terminal frame type equipment where the service board corresponding to the target service board identification is positioned, sending the backup message to a switching chip of the opposite terminal frame type equipment to enable the switching chip of the opposite terminal frame type equipment to send the backup message to the service board corresponding to the target service board identification, and storing, by the service board, the backup data carried in the backup message. By the switching chip and the target service board identification of the backup message, data backup of the service board can be realized; no backup interface is set on the service board, and no connection with an external wire is needed; and therefore, the setting and external wiring processes are reduced, and the usability and the maintainability of the frame type equipment are improved.

The invention provides a photoelectric oscillation loop based onboard microwave photon transponder, which is characterized in that optical generation, distribution and processing of high-performance microwave local oscillation signals are combined in design, advantages of a microwave technology and optical fiber communication are given into full play, bandwidth limitations of frequency conversion of high-band communication signals are solved, the complexity of the system is reduced, the mass and the volume of the system are reduced, the temperature stability and the electromagnetic interference resisting capacity of the system are enhanced, and the transponding efficiency is improved. The microwave photon transponder comprises a microwave local oscillation source and multi-channel output. The microwave local oscillation source is composed of a photoelectric oscillation loop, wherein the photoelectric oscillation loop leads photonic signals to a multi-channel output port through multiple optical fibers, signal processing is realized by means of photonic processing at the multi-channel output end, photoelectric conversion is performed, and multi-channel transponding is realized.

The present invention relates to helical antenna technology. The invention discloses a helical reflective antenna and a high-power capacity array and a transmitting system formed by the helical reflective antenna. A helical reflective antenna for reflecting electromagnetic waves, comprising a reflective surface, a helical antenna and a rotating mechanism; The helical antenna is arranged in front of the reflection and fixed on a support shaft; The helical antenna is coaxial with the support shaft, and the starting point thereof is located on the support shaft axis; The supporting shaft is connected with a rotating mechanism; The rotating mechanism is used for driving the support shaft to rotate and adjusting the phase of the reflected electromagnetic wave. A high-power-capacity helical reflective antenna array is composed of the helical reflective antennas arranged in an array. The high-power-capacity helical reflective antenna transmitting system of the present invention is composed ofthe high-power-capacity helical reflective antenna array and a feed source. The invention improves the bandwidth of the high-power microwave radiation antenna, and has the characteristics of flexiblearray, easy conformal and the like.

The invention discloses a method for generating a tunable ultra-wideband (UWB) microwave frequency comb based on a semiconductor laser. The method comprises steps of: using a semiconductor laser to produce the tunable UWB microwave frequency comb, wherein the temperature and the current of the semiconductor laser are controlled by a current temperature control source; using an external signal source to modulate the driving current of the semiconductor laser, causing the semiconductor laser to output a seed source of the microwave frequency comb by adjusting the modulation frequency fm and the modulation power Pm of an signal source output signal; injecting continuous light output by an adjustable laser source into the current-modulated semiconductor laser, using a bandwidth enhancement effect caused by light injection to cause the semiconductor laser (SL) to produce the high-quality tunable UWB microwave frequency comb. The method can produce the microwave frequency combs with a continuously variable comb distance from 0.5GHz to 10GHz. The high-quality microwave frequency comb obtained in two adjustable comb distance ranges from 1.1GHz to 1.2GHz and from 3.3GHz to 8.0GHz can achieve a bandwidth up to 59GHz (within 10dB flatness amplitude).

The invention discloses a novel digital double-input three-path Doherty power amplifier device, comprising a power divider and a second peak power amplifier, wherein the power divider is used to divide a first input signal into two equal power or unequal power, and one signal output end of the power divider is connected with the signal input end of a carrier power amplifier through a first phase compensation line or in a direct mode to form a power amplifier branch; one signal output end of the power divider is connected with the signal input end of a first peak power amplifier through a second phase compensation line or in a direct mode, and the signal output end of the peak power amplifier is connected with a first impedance compensation line to form a power amplifier branch; the second peak power amplifier receives a second input signal, and the signal output end of the second peak power amplifier is connected with a second impedance compensation line to form a power amplifier branch; and the three power amplifier branches are serially connected with a load impedance conversion circuit after parallel connection, wherein the phase and amplitude of two input signals can be adjusted. Compared with a traditional asymmetrical two-path Doherty power amplifier, the problem of efficiency recession in output power back-off intervals can be improved, and thus the average efficiency of the power amplifier can be greatly increased.

The invention relates to a hard disk audio vibration adaptive feedforward control method based on earphone jack signal extraction. In the prior art, adaptive feedforward compensation performance is limited by a sensor measuring bandwidth. In the invention, the above defect is overcome. The method comprises the following steps of extracting and digitizing an audio signal; carrying out mechanical transmission function recognition; and calculating the feedforward compensation signal of position error control. In the invention, an adaptive feedforward method based on a loudspeaker is used to reduce system cost, and simultaneously, the bandwidth limitation of a hard disk driver servo system is avoided.

The invention discloses a reconfigurable inter-stage matching broadband CMOS power amplifier, and belongs to the technical field of integrated circuits. A received radio frequency input signal is amplified by a driving-stage amplifier and then output to a power-stage amplifier through a reconfigurable inter-stage matching network to be amplified and then output; the reconfigurable inter-stage matching network comprises a CLC matching network, a reconfigurable matching capacitor, a reconfigurable matching inductor and two groups of switches; the two groups of switches are respectively connectedwith the reconfigurable matching capacitor and the reconfigurable matching inductor in series; according to different working frequency bands, the equivalent inductance values of the parallel inductor and the reconfigurable matching device in the CLC network are changed through on-off of the switch, so that the reconfiguration of the matching network is realized. The high-Q-value interstage impedance matching network is simple and reliable in structure, does not influence output power and efficiency, does not increase power consumption, can realize relatively high gain, and can ensure that multiple frequency bands meet high output power and high efficiency, thereby overcoming bandwidth limitation of the high-Q-value interstage impedance matching network and realizing broadband application.

The embodiment of the invention discloses a Doherty power amplification circuit, a power amplifier, a terminal and a base station. The Doherty power amplification circuit comprises an input network which is used for decomposing an input signal into a first signal and a second signal and outputting the first signal and the second signal; The main transistor which is used for receiving the first signal and amplifying the first signal to generate a first amplified signal; The peak transistor which is used for receiving the second signal and amplifying the second signal to generate a second amplified signal; The broadband load modulation network which is connected with the output end of the main transistor and the output end of the peak transistor and used for synthesizing and outputting the first amplification signal and the second amplification signal, Wherein the relative bandwidth of the broadband load modulation network is greater than a preset threshold; And the output matching network which is used for receiving and outputting the synthesized signal, and converting the output impedance of the broadband load modulation network into a preset impedance matched with a post-stage circuit. By adopting the embodiment of the invention, the Doherty power amplification circuit can support a broadband application scene.

The invention is applicable to the technical field of communication, and provides a single-fiber bidirectional optical component and an optical module. The single-fiber bidirectional optical component comprises a light transmitting unit, a light receiving unit and a planar optical waveguide chip; the light transmitting unit is used for transmitting an emergent light signal with a first wavelength; the light receiving unit is positioned below the planar optical waveguide chip and is used for receiving an incident light signal with a second wavelength; the planar optical waveguide chip comprises a wave splitting and combining device, a reflecting surface, a first port and a second port, and the wave splitting and combining device is used for sending out an emergent optical signal received through the first port through the second port and sending an incident optical signal received through the second port to the optical receiving unit through the reflecting surface; and the reflecting surface is arranged between the wave splitting and combining device and the light receiving unit and is used for reflecting an incident light signal passing through the wave splitting and combining device into the light receiving unit. The single-fiber bidirectional optical assembly provided by the invention is small in size, simple in structure and low in cost, and can be applied to a high-speed communication network.

The invention discloses a sensorless control method for a high-speed permanent magnet synchronous motor. The method can improve the dynamic performance of the high-speed permanent magnet synchronous motor in a static or low-speed region while reducing the noise generated by a conventional high-frequency injection method. And stable operation of the motor in dynamic operation processes of sudden loading, load shedding and the like can be ensured.

The invention discloses a device and method for generating a flat broadband microwave frequency comb based on a cascaded modulated light injection semiconductor laser, and relates to the technical field of microwave photons. The device comprises a signal source module, a direct modulation module, a direct light modulation injection module, a phase shifter, a phase modulator, a phase light modulation injection module, an optical circulator, a semiconductor laser and a detection module, wherein the signal source module is used for providing electric signals required by direct modulation and phase modulation. The generator adopts a direct modulation structure to generate a seed optical frequency comb, and has the advantages of being easy to implement, convenient to tune and the like, and the comb distance can be continuously adjusted only by simply changing the frequency fm of a direct modulation electric signal; a cascade structure of direct modulation and phase modulation is adopted, bandwidth limitation of electronic devices can be avoided, and broadband frequency comb signals are generated; the phase shifter is adopted to match the phases of the direct modulation signal and the phase modulation signal, so the power of each comb line can be balanced to a certain extent.

The invention discloses a distributed storage network and a data distributed storage method, where the distributed storage network comprises: data providing server for providing data for user terminals; user access equipment, used to connect user terminals to network and comprising a memory cell for storing data to be sent to user terminals; data broadcast control, according to request of a user terminal, sending data from data providing server or user access equipment or other user terminals to this user terminal. under the centralized management and control of the data broadcast control server, it makes data able to be distributedly stored in network equipment and assures validity and safety of data storage and transmission.

A sensor data processing apparatus can be coupled to multiple image sensors of different types. The apparatus determines a geolocation of areas imaged in each frame or pixel based on sensor geolocation information and encodes the geolocation information in metadata space of the corresponding frame. The apparatus is configured to align edges and / or corners of the frame with edges or corners of adjacent frames based on the geolocation information to stitch together a mosaic or panoramic image without overlapping frames. The apparatus can be figured to stitch together image frame in real time without performing feature registration and without resampling frames.

The invention provides an inverter-based low-noise amplifier, a receiver and electronic equipment, and the low-noise amplifier comprises a first inverter, a second inverter and a third inverter; the input end of the first phase inverter is directly or indirectly connected with a signal receiving end, the output end of the first phase inverter is connected with the input end of the second phase inverter, the output end of the second phase inverter is connected with the input end of the third phase inverter, and the output end of the second phase inverter and the output end of the third phase inverter are connected with a frequency mixer, so as to output a differential signal to the frequency mixer; the first phase inverter, the second phase inverter and the third phase inverter are all CMOSphase inverters.

The invention relates to an antenna panel, a vortex beam antenna and a working method of the vortex beam antenna, belongs to the technical field of vortex beam antennas, and solves the problems that an existing vortex beam transmitting device is high in frequency dependence and limited in working bandwidth due to phase shift through a phase shift feed network. The antenna panel comprises at least one antenna array, which comprises a plurality of antenna units which are uniformly distributed along the circumference, wherein the orientation angles of the plurality of antenna units are sequentially changed along with the change of the direction angles of the antenna units. The vortex beam antenna comprises the antenna panel and power dividers arranged below the antenna panel, wherein the number of layers of the power dividers is consistent with the number of antenna arrays, and the power dividers are connected with the antenna arrays in a one-to-one correspondence mode and used for achieving power distribution. According to the working method of the vortex beam antenna, the power divider is connected with a signal transmitter, a radio frequency excitation signal is provided through the signal transmitter, and transmission of vortex beams is achieved. According to the technical scheme, the problems existing in the prior art can be well solved.

The invention discloses a polarization loop adjustment system suitable for narrowband communication, which includes an intermediate frequency signal source, an intermediate frequency phase detector, a first peak detector, a low-pass filter, a second peak detector, a down converter, a radio frequency synchronization source, First audio amplifier, second audio amplifier, voltage controlled oscillator, power amplifier, comparator, described first peak detector and intermediate frequency phase detector are respectively connected with intermediate frequency signal source, described first peak detector and second The audio amplifier is connected, the second audio amplifier is connected with the power amplifier, the low-pass filter is connected with the intermediate frequency phase detector, the low-pass filter is connected with the first audio amplifier, and the first audio amplifier is connected with the voltage-controlled Oscillation source connection. The present invention prevents the operating bandwidth from being limited by the bandwidth of the phase and amplitude amplifiers through the mutual cooperation among the second peak detector, the audio amplifier, the voltage-controlled oscillator and the power amplifier, so that the polarization loop adjustment system is suitable for narrow-band communication.

The invention discloses a transmission system for an ultra-dense wavelength division multiplexing passive optical fiber network, and relates to the technical field of high-speed optical access networks. According to the transmission system for the ultra-dense wavelength division multiplexing passive optical fiber network, a wavelength division multiplexing and demultiplexing device and an opticalbeam splitter are mixed for use, thereby avoiding the problem that high loss occurs when using the optical beam splitter alone for multiple users, and avoiding the problem that the number of users islimited when using a wavelength division multiplexer alone; meanwhile, by ingeniously designing the upstream and downstream wavelength, the bandwidth limitation of the wavelength division multiplexer / demultiplexer can be effectively avoided, so that the system performance of multipath downstream signals and multipath upstream signals in each group of wavelength division multiplexing channels are guaranteed; and a crosstalk is not introduced in a single-fiber two-way transmission, thereby remarkably improving the capacity and the number of users of the upstream and downstream access signals. The invention further discloses a transmission method based on the transmission system for the ultra-dense wavelength division multiplexing passive optical fiber network.