75results about How to "Reduce gain" patented technology

An electric power assisted steering assembly comprises a steering mechanism which operatively connects a steering wheel to the roadwheels of a vehicle, a torque sensing means adapted to produce a first output signal indicative of the torque carried by a portion of the steering mechanism, a means for producing a second output signal indicative from a signal indicative of the angular velocity of the portion of the steering mechanism, an electric motor operatively connected to the steering mechanism, a signal processing unit adapted to receive the two output signals and to produce therefrom an overall torque demand signal representative of a torque to be applied to the steering mechanism by the motor, and a motor drive stage adapted to provide a drive current to the motor responsive to the torque demand signal. The overall torque demand signal includes a damping component that is dependent upon the second output signal. The means for producing the yaw damping component includes a filter having one pole and one zero, and in use the second signal is passed through the filter to produce the damping component, the frequency of the pole and zero being selected such that the filter provides a band between the pole and zero within which the phase of the filtered second signal and the velocity signal are further out of phase or in phase than within the band.

The invention relates to an anti-deception-interference joint detection method and system based on space-time frequency, and the method comprises the steps: obtaining a signal source direction of a received satellite signal, and dividing the signal source direction into channels according to angles based on a beam forming criterion; based on a preset capture rule, initiating capture search for the signal in each channel, and synchronously performing correlation peak detection and array antenna anti-interference detection on the signal to obtain angle information of the signal in each channel and satellite PRN information in the capture process; null processing is carried out on the signal source directions of two or more satellite signals appearing at the same angle; outputting a capture result based on the capture rule, and tracking the capture result conforming to the capture rule; doppler frequency shift consistency detection and signal power calculation are carried out on the signals subjected to rotation tracking, and deception signals are recognized and fed back to the antenna array for filtering processing. The application has the effects of expanding the application range of the anti-deception jamming detection method and improving the anti-jamming capability of navigation positioning.

The present invention discloses a laser positioning method and a robot based on image information. The execution subject of the laser positioning method is a robot equipped with a structured light module. The structured light module includes a line laser transmitter and a camera without an infrared filter, so that the imaging information of infrared light and the imaging information of visible light are retained in the image captured by the camera. The laser positioning method includes the following steps: the robot controls the camera to capture an image of light reflected back from the surface of an object to be measured by the line laser emitted by the line laser transmitter, and detects the brightness and darkness type of the image captured by the camera. When the robot detects that the current frame image captured by the camera is a bright frame image, the robot searches for the position of the line laser from the current frame image by executing an inter-frame tracking algorithm. When the robot detects that the current frame image captured by the camera is a dark frame image, the robot extracts the position of the line laser from the current frame image by executing a brightness centroid algorithm.

The invention belongs to the technical field of antennas, and particularly relates to a low-sidelobe X-waveband waveguide slot array antenna. The antenna comprises an antenna array plane, the antenna array plane comprises a plurality of sub-array antennas which are arranged in parallel at equal intervals, each sub-array antenna is a waveguide slot array antenna, each waveguide slot array antenna is externally connected with a TR assembly, and the center-to-center distance d1 between every two adjacent waveguide slot antennas is 16mm; according to the technical requirements, horizontal polarization is achieved in the mode that an inclined slot is formed in the narrow side of a rectangular waveguide, finally, the design of the low-sidelobe horizontal polarization waveguide slot traveling wave array antenna is achieved, and the sidelobe level in the antenna working frequency range averagely meets the design target that the sidelobe level of a transmitting pitching face is lower than-12dB, the sidelobe level of a receiving pitching face is lower than-25dB, and the sidelobe level of the receiving pitching face is lower than-25dB. According to the invention, the side lobe level of the azimuth plane is lower than-25dB, the normal transmitting gain is greater than 35dBi (full-band), the receiving gain is greater than 33.5 dBi, and the antenna has the advantages of low side lobe, high gain and narrow beam, and is suitable for being applied to an X-band radar communication system.

The invention relates to the technical field of wireless communication, and provides a power amplifier and a radio frequency front-end module, and the power amplifier comprises an input matching circuit, a first-stage amplifier, a second-stage amplifier, an inter-stage matching circuit and a third-stage amplifier which are electrically connected in sequence; the first current unit, the second current unit and the third current unit respectively provide bias current for the input end of the first-stage amplifier, the input end of the second-stage amplifier and the input end of the third-stage amplifier; the first-stage amplifier comprises a first triode, a first resistor, a first capacitor and a first inductor, the base electrode of the first triode serves as the input end of the first-stage amplifier, the emitter electrode of the first triode is connected with the first resistor in series and then grounded, and the collector electrode of the first triode is connected with the first end of the first inductor and the first end of the first capacitor; the second end of the first capacitor serves as the output end of the first-stage amplifier. The power amplifier disclosed by the invention can be used for reducing the output nonlinear noise under the condition of meeting high gain.

The invention discloses a sliding mode-extended state observer vibration control method based on time delay compensation in the field of vibration control. The sliding mode-extended state observer vibration control method comprises the following steps: step 1) carrying out novel modeling on a four-side fixed support plate system; 2) designing an extended state observer; 3) designing a sliding mode controller; 4) designing a time delay compensator; and step 5) calculating the control quantity by using the NI-PCIe acquisition card and the Simulink. According to the invention, based on NI-PCIe hardware-in-the-loop platform development, the problems of system time lag, model uncertainty, influence of an inertial actuator and external excitation existing in a four-side fixed support plate are solved, and the total disturbance of the system including internal and external disturbance is estimated through an extended state observer. A content system is simplified into an integral series connection type for control by eliminating total disturbance through feedforward, and a delay compensator based on an enhanced differentiator is introduced to carry out non-delay design on the system, so that the vibration suppression performance of the sliding mode controller is improved.

The invention discloses a broadband wide-beam microstrip dipole antenna and a processing method thereof, and relates to the technical field of antennas. Comprising an antenna substrate and a metal bottom plate, the antenna substrate is installed on the metal bottom plate and is mutually orthogonal to the metal bottom plate, a microstrip dipole and a folding oscillator arm are arranged on the front face of the antenna substrate, and a feed balun is arranged on the back face of the antenna substrate and penetrates through the metal bottom plate to be connected with a feed signal source. A feed signal source passes through the metal bottom plate and is connected with the microstrip dipole antenna; the feed balun and the microstrip dipole line are insulated from each other. The number of the folding oscillator arms is two, and the folding oscillator arms are symmetrical relative to the center of the microstrip dipole line. On the basis that the basic microstrip form of the microstrip dipole antenna is not changed, the problem that the E-plane beam width of a traditional dipole antenna is narrow is effectively solved through the mode that the annular parasitic branches are introduced into the tail ends of the two oscillator arms of the dipole antenna, and meanwhile it is guaranteed that the microstrip antenna is low in machining difficulty, low in cost and small in size.

The utility model provides an ultra wide band antenna, the ultra wide band antenna includes feed transmission line, ground plate, dielectric slab, radiation unit, ground plate, dielectric slab and radiation unit stack connection in proper order, feed transmission line is electrically connected with radiation unit, radiation unit includes patch antenna and via hole, and the patch antenna is electrically connected with the dielectric slab. The patch antenna is provided with the via holes, the feed transmission line is electrically connected with the patch antenna, the plurality of via holes are arranged at the edge position of the patch antenna, and the via holes penetrate through the dielectric plate and are communicated with the grounding plate. According to the patch antenna provided by the utility model, through adding the via hole, resonance which can be realized by half wave originally required can be realized with a smaller size under the condition that no slot is formed. Besides, miniaturization of the antenna area is realized, the polarization influence of the antenna is reduced, the radiation efficiency is increased, and the damage to the antenna gain is reduced, so that the positioning precision and distance are improved.

The invention discloses a temperature compensation circuit, a power amplifier and a radio frequency front-end module, and the temperature compensation circuit comprises at least one first temperature compensation module, at least one second temperature compensation module, and an adjustment module which is connected with the first temperature compensation module and the second temperature compensation module. The adjusting module is connected with the power supply end of the power amplifier; the first temperature compensation module is used for outputting a first compensation signal to the compensation node in a first temperature interval, and the first compensation signal is in positive correlation with the temperature; the second temperature compensation module is used for outputting a second compensation signal to the compensation node in a third temperature interval, the second compensation signal is in positive correlation with the temperature, and the minimum value of the third temperature interval is larger than the maximum value of the first temperature interval; wherein the adjusting module is used for detecting the power supply voltage of the power amplifier in a first temperature interval and adjusting a first slope between the first compensation signal and the temperature according to the power supply voltage, and the power supply voltage is in positive correlation with the first slope.

The invention relates to a cavity length locking device and method of a low-cost optical resonant cavity based on a phase-locked loop. The device mainly comprises a reference laser frequency stabilization structure and a cavity length locking structure of the optical resonant cavity. The method comprises the following steps: locking the frequency of a reference laser at an atomic resonance point through a saturated absorption frequency stabilization method, coupling laser containing a modulation component into an optical resonant cavity, collecting a transmission spectrum, taking a phase-locked loop as a basis, and taking a modulation signal in a frequency stabilization loop of the laser as a reference; a demodulation signal with the same frequency and adjustable phase is obtained through phase locking and used for demodulating an error signal for locking the cavity length of the optical resonant cavity, and the cavity length of the optical resonant cavity can be locked through the error signal. According to the invention, an external optical modulation device is not needed, so that the cost is greatly reduced, the method is not limited by the modulation bandwidth, and an error signal with a relatively low frequency discrimination slope can be demodulated, thereby reducing the loop gain, enlarging the frequency discrimination range, and reducing the influence of a control system on the fineness of the optical resonant cavity.

The invention relates to the technical field of wireless communication, and discloses a low orbit satellite communication K / Ka frequency band broadband dual circularly polarized antenna. According to the technical scheme, the antenna is characterized by comprising a radiation port surface, a resonant cavity, a dual-circular polarizer, a quasi-TEM transmission air cavity layer, a left polarization broadband feed network layer, a right polarization broadband feed network layer, a TEM mode conversion terminal, a polarization switch, a transceiving duplexer, a first standard waveguide port layer and a second standard waveguide port layer. The antenna is simple in structure, has a self-packaging characteristic, is good in electromagnetic compatibility, and can achieve the high gain, wide bandwidth and high circular polarization purity of the antenna. The shielding air cavity is formed by structure stacking and the metalized through holes, and when a plurality of circuits are integrated together, mutual interference is small, the structure is compact, assembling is convenient, and electrical performance is excellent.

The invention relates to reading of an RFID transponder on an object in a device. The invention relates to a system comprising a device (10) for receiving at least one object (12a-12b) and an object (12a-12b) arranged in the device (10), in which an RFID transponder (14) with an antenna (15) is arranged on the object (12a-12b), and in which the device (10) has at least one wall (18) and at least one resonant structure (20) spaced apart from the object (12a-12b). In this case, the resonating structure (20) is introduced as a slot structure into the wall (18).

The invention relates to a latch-free fail-safe and fault tolerant input / output interface. An input / output (I / O) interface includes a set of complementary metal oxide semiconductor (CMOS) transistors in a P-type substrate. A first N-type region is in a substrate, a second N-type region is in the substrate, spaced apart from the first N-type region, and the second N-type region is a deep-N well (DNW). The first heavily doped P-type region is arranged between the first N-type region and the second N-type region, and the first heavily doped P-type region is coupled to the ground. A second heavily doped P-type region is in the first N-type region, the second heavily doped P-type region coupled to the output terminal. A first heavily doped N-type region is in the first N-type region, the first heavily doped N-type region coupled to a floating well (FW) terminal. A second heavily doped N-type region is in the second N-type region. A resistor is coupled to the DNW, and the resistor is coupled to the voltage source terminal.

The invention discloses a quasi-single-mode circular waveguide conical horn antenna, a radar and a communication device. The quasi-single-mode circular waveguide conical horn antenna comprises a circular waveguide section and a conical horn section. Conductor loss is reduced by remarkably increasing the diameter of the circular waveguide, and axial periodic annular grooves are formed in the inner wall of the circular waveguide to form a spatial mode filter and a selective attenuation high-order mode, so that high radiation efficiency and high mode purity are realized at the same time in a millimeter wave frequency band. And the conical horn section adopts an index profile to realize high-directionality radiation. The antenna structure effectively solves the technical problems of large loss and impure mode in a millimeter wave high-frequency band in the traditional design.

The present invention provides an antenna device, which has multiple antennas in a common housing, can suppress the decrease of antenna gain and achieve miniaturization. The antenna device (1) has a TEL antenna (2) and a capacitive load element (3) in a common housing. The capacitive load element (3) is located above the TEL antenna (2). The length of the capacitive load element (3) is a natural number multiple of 1 / 2 of the wavelength of the PCS band. The TEL antenna (2) is arranged to avoid the maximum voltage point of the standing wave of the PCS band generated by the capacitive load element (3).

The invention provides a broadband gain positive slope amplitude-phase control multifunctional chip for a T / R assembly, which relates to the technical field of radio frequency integrated circuits and comprises a receiving channel, a transmitting channel, an equalization circuit, a numerical control attenuator, a numerical control phase shifter, a transmitting-receiving change-over switch module and a parallel control module. The parallel control module is used for outputting parallel control signals to the numerical control attenuator, the numerical control phase shifter and the transceiving change-over switch module; the equalization circuit is respectively connected with the receiving channel and the transmitting channel through the transmitting-receiving change-over switch module, so that a signal path of the receiving channel and a signal path of the transmitting channel multiplex the equalization circuit, the numerical control attenuator and the numerical control phase shifter; and the equalization circuit is of an on-chip integrated structure and is used for adjusting the gain of the receiving channel and the gain of the transmitting channel to present a positive slope characteristic relative to the frequency in a wide frequency band so as to compensate the frequency attenuation of an external device.

The invention discloses a starting circuit for suppressing starting overshoot, which is integrated in a DCDC converter and does not need an external expansion special device. The circuit comprises a reference voltage module, a step voltage slow rising module, a timer and an operational amplifier self-bias module. The step voltage slow rising module generates a soft start voltage signal VSTART to a first positive input end of the operational amplifier self-bias module, the reference voltage module outputs a reference voltage VREF to a second positive input end of the operational amplifier self-bias module, and a negative input end of the operational amplifier self-bias module inputs a feedback voltage VFB; the timer outputs a starting enable signal of the operational amplifier self-bias module; the soft start voltage signal VSTART generated by the step voltage slow-rise module realizes that the output voltage in the starting stage of the DCDC converter slowly rises from 0 to a rated value, and starting surge current and voltage overshoot are effectively inhibited.

The invention relates to a voltage drop control circuit of an operational amplifier and an operational amplifier circuit, and the voltage drop control circuit comprises a detection module and a voltage division module. The voltage dividing module comprises a bypass switch and a voltage dividing device; the detection module is used for generating a voltage division control signal according to the power supply voltage of the operational amplifier and outputting the signal to the bypass switch; the bypass switch is switched off in response to a first voltage division control signal generated when the power supply voltage is greater than a detection threshold value, so that the connection between the voltage division device and the gain stage of the operational amplifier is conducted; the bypass switch is switched on in response to a second voltage division control signal generated when the power supply voltage is smaller than or equal to the detection threshold value so as to disconnect the voltage division device and the gain stage; the voltage drop control circuit can ensure that the gain of the operational amplifier is not obviously reduced when the power supply voltage is high, so that the operational amplifier can keep stable gain in a wider power supply voltage range, the circuit structure is simple, and the cost and the implementation difficulty are reduced.

The invention discloses a power converter, which is a magnetic integrated current doubling rectifying circuit with a low transformer transformation ratio, and can not only improve the effective duty ratio of a system, but also reduce the gain of the circuit by adjusting the connection mode of a synchronous rectifying tube and a corresponding bridge arm. Therefore, the power converter can reduce the turn ratio of the transformer under the condition of the same output voltage, thereby reducing the loss of the transformer and reducing the cost of the transformer.

The invention discloses a pulse-modulated radio frequency power amplifier system and a magnetic resonance system. The amplifier system comprises a nonlinear correction unit, a radio frequency pre-amplification and driving amplification unit, a radio frequency power amplification unit, a directional coupler, a pulse synchronous switch unit and a filtering unit. Wherein the non-linear correction unit, the radio frequency pre-amplification and driving amplification unit, the radio frequency power amplification unit and the directional coupler form a closed loop, and the filtering unit is used for filtering signal components lower than a preset working frequency band in the formed closed loop, so that the gain of a low frequency band is reduced, the condition of self-excitation oscillation is destroyed, and the self-excitation performance of the antenna is improved. The self-excitation is avoided, the problem of potential instability of a low-frequency band in a radio frequency power amplifier system is solved, the whole system can work more stably and reliably, meanwhile, pulse modulation of sub-microsecond-level stable time can be achieved, and the problem is solved simply at low cost only by reasonably using the filtering function.

An antenna structure comprises a first conductive layer, a dielectric layer and a second conductive layer which are sequentially stacked in the thickness direction. The first conductive layer comprises at least one patch, each patch comprises a body, two feed points distributed at intervals and two annular grooves distributed at intervals, and each annular groove is arranged around one feed point so as to separate the body from the feed point. The antenna structure comprises two feed holes corresponding to each patch, each feed hole penetrates through the dielectric layer, one end of each feed hole is electrically connected with a feed point, and the other end of each feed hole is electrically connected with the second conductive layer. The antenna structure is beneficial to bandwidth expansion.

The application discloses a control method of structural vibration based on a controller saturation lower band active mass damper, and successfully reduces the vibration of a building structure by introducing an active mass damper and applying a control strategy. In order to meet the control input constraint and performance requirements, a state feedback optimal control law under the controller saturation is proposed by using a linear matrix inequality method; example analysis shows that the proposed control strategy can realize the stability of the closed-loop system and play the best performance, while reducing the control energy consumption and the floor level disturbance; compared with the case without considering the controller saturation, the proposed controller has smaller gain, reduces the energy consumption, and shows better anti-interference performance; numerical examples verify the effectiveness and feasibility of the proposed controller within the saturation limit; the application provides a new idea and method for solving the actual building structure control problem, and has important theoretical significance and practical application value.

The application belongs to the technical field of control, and particularly relates to a kind of water-soluble fertilizer production preparation self-adaptive control method and system, method includes: the state parameter in reactor is collected, and after normalization, constitute multidimensional state vector;Through Gaussian process regression, the nonlinear mapping between current state and control input and state change is established, and the trace of predictive covariance matrix is used to represent posterior uncertainty index;Establish a stochastic differential equation containing Brown motion and compound Poisson process as a state space model, associate volatility, jump intensity and posterior uncertainty index to represent unmodeled dynamic risk;For concentration, pH value and temperature constraints, construct a stochastic control barrier function, and derive high probability safety constraints based on Itô-Lévy formula;With the minimum control cost and index deviation as the goal, a convex optimization problem is constructed, and the control amount is solved online to regulate the feeding, stirring and temperature control equipment, so as to consider the control cost, index deviation and production safety.

The invention discloses a continuous two-dimensional beam frequency scanning circularly polarized antenna and a design method thereof, and the method comprises the steps: determining a first high-order resonance mode which is used for representing the first resonance of an antenna working frequency band; determining whether a first high-order resonance mode exists on the sector-ring-shaped patch structure or not, wherein the sector-ring-shaped patch structure is an antenna radiation unit structure; and if the first high-order resonance mode exists on the sector-ring-shaped patch structure, adjusting the arc length of the outer arc of the sector-ring-shaped patch structure and the ratio of the arc length of the inner arc to the arc length of the outer arc of the sector-ring-shaped patch structure so as to form the first high-order resonance mode on the sector-ring-shaped patch structure.

The invention provides an indoor ultra-wideband transparent directional antenna, which comprises a transparent outer cover, a transparent bottom plate, a base, a first rhombus array and a second rhombus array, and is characterized in that each of the first rhombus array and the second rhombus array comprises four transparent oscillators, and the four transparent oscillators are arranged in a rhombus shape; the first rhombus array is connected with the first feed network, and the second rhombus array is connected with the second feed network. The diamond array can maximize the diagonal distance between the units, which is crucial for suppressing the grating lobes of the antenna, especially for suppressing the grating lobes at the high-frequency end. And the grating lobes can cause energy to radiate towards unwanted directions, so that the gain and efficiency of the antenna are reduced. The four transparent oscillator diamond arrays achieve good balance among performance, flexibility, complexity and cost.

The invention discloses a variable pitch control method for a permanent magnet direct-drive wind power system of a floating offshore wind turbine, comprising the following steps: S1, obtaining the output power of the generator set; S2, performing a difference operation between the output power of the generator set and the rated power to obtain the power deviation of the generator set, and calculating the power deviation rate of the generator set within a period of time; S3, designing a dual-input, three-output fuzzy PID control model, inputting the power deviation and the power deviation rate obtained in step S2 into the fuzzy PID control model, the fuzzy PID control model making corresponding decisions through neural fuzzy reasoning, and adjusting PID parameters online to meet the self-tuning requirements of the power deviation and the power deviation rate at different times on the PID parameters, thereby obtaining the best adjustment of the pitch angle change target; S4, repeated compensation control, embedding repeated control based on the internal model principle into the fuzzy PID control, and forming a fuzzy PID control based on repeated compensation.

The present invention provides an adaptive capacitor radiation-resistant high-frequency SOI power amplifier circuit structure, which belongs to the field of radio frequency integrated circuits and includes a four-stack power amplifier, a radiation detection control circuit and a switch capacitor array. The four-stack power amplifier includes four-stack transistors, bias resistors and radio frequency choke inductors; the radiation detection control circuit includes a radiation detection circuit and a threshold detector; the switch capacitor array is composed of switch transistors and capacitors. Due to the total dose irradiation effect, when irradiated, the performance of the transistor will decrease, and the performance of the power amplifier will also decrease. The present invention adds an adaptive switch capacitor array to the traditional four-stack power amplifier, and adaptively adjusts the capacitor size under irradiation conditions, which can significantly improve the degradation of the power amplifier performance caused by irradiation. At an operating frequency of 10 GHz, compared with the traditional four-stack power amplifier, the gain, power added efficiency and saturated output power of the present invention are significantly improved in an irradiation environment of 300 krad.

The invention belongs to the technical field of antennas, and relates to a polarization-adjustable transmission unit and a directional diagram reconfigurable transmission array antenna. The polarization-adjustable transmission unit comprises a first patch layer, a first dielectric layer, a floor layer, a second dielectric layer and a second patch layer; the first patch layer comprises a first radiation patch, a second radiation patch and two diodes connected with the first radiation patch and the second radiation patch; the first radiation patch is arranged in the center of the top of the first dielectric layer, and the diagonal line is collinear with the diagonal line of the first dielectric layer; the second radiation patch sleeves the outer side of the first radiation patch at an interval, an inner ring is of a square structure, and an outer ring is of a circular structure; the working states of the two diodes are different; two loading grooves which are recessed towards the center direction of the first dielectric layer are formed in positions, corresponding to the diagonal line of the first dielectric layer, of the outer ring of the second radiation patch; and the second patch layer is connected with the first patch layer. According to the invention, transmission conversion can be realized, and reconfigurable directional diagrams are supported.

The present invention provides a radio frequency power amplifier and a radio frequency power amplifier module, wherein the radio frequency power amplifier comprises a signal input terminal, an input matching circuit, a power amplification circuit, an output matching circuit, a signal output terminal and a bias circuit; the bias circuits all comprise a first triode, a second triode, a third triode, a first resistor, a second resistor, a first capacitor, a first field effect transistor, a second field effect transistor and a third capacitor. The present invention designs a new bias circuit so that the gain of the radio frequency power amplifier will not decrease with the increase of temperature.

A signal adjustment method for a PPG apparatus and a PPG apparatus. The method comprises: when background light data does not meet a preset background light data range, or actual effective light data does not meet a preset first effective light data range, performing a dimming operation, the dimming operation comprising: determining an estimated current transfer ratio; estimating a driving current required by a light source and a gain required by an analog front end; calculating estimated effective light data of a PPG apparatus according to the estimated driving current required by the light source, the gain required by the analog front end, and the estimated current transfer ratio; when the estimated effective light data meets a preset second effective light data range, generating, according to the estimated driving current required by the light source and the gain required by the analog front end, a current / gain value to be adjusted. The signal adjustment method can enable a PPG signal to quickly and adaptively converge within a dynamic range of an ADC.