110 results about "Dc bias voltage" patented technology

A control method and system for a resonant converter. The control method for a resonant converter comprises: in each switching cycle, determining a target power value on the basis of an input power control amount and a compensation amount corresponding to a bridge leg (S101); on the basis of the target power value, an input voltage, circuit parameters of the resonant converter, and the current operating mode of a full-bridge inverter module, determining a target slope control amount corresponding to a counter which corresponds to a switching transistor (S102); determining a comparison threshold on the basis of the target slope control amount, the current count value of the counter which corresponds to the switching transistor, and a DC bias voltage of a resonant capacitor corresponding to the current operating mode, wherein the counter starts counting using the DC bias voltage as an initial value in each switching cycle until the actual voltage of the resonant capacitor is equal to the comparison threshold (S103); and determining a control signal on the basis of the actual voltage of the resonant capacitor and the comparison threshold, and controlling the switching transistor on the basis of the control signal (S104).

The invention discloses a DP-MZM-based reconfigurable mixer with phase shift and image rejection functions, and belongs to the field of microwave photon signal processing. By adjusting an input radio frequency signal and a direct current bias voltage of the DP-MZM1, four different LO frequency doubling and mixing functions can be realized. By controlling the angle alpha between the polarization direction of the polarization analyzer and one axis of the modulator, the phase of the generated signal can be flexibly tuned in the range of 0-360 degrees. When combined with the optical frequency comb, the multi-channel multi-band frequency conversion system can be expanded into a multi-channel multi-band frequency conversion system with independent phase tuning capability by utilizing the channel switching and frequency slot selection functions of the wavelength selection switch, and parallel output of various frequency mixing results can be realized. By adjusting the phase difference between the two-channel output signals, I / Q mixing, double-balanced mixing and image rejection mixing can be configured. The scheme is not influenced by direct current bias drift, the system complexity is reduced, and the frequency conversion efficiency is improved.

The invention discloses a wide-temperature-range solid insulation space charge measurement method, and belongs to the technical field of electrical insulation test and dielectric physical measurement. A solid insulation sample is mounted between double-layer composite electrode modules in a closed high-low temperature test cavity, and a flexible compensation gasket is adopted to absorb thermal expansion difference; a PID closed-loop control system is utilized to realize accurate and stable control of the temperature of the sample in a wide temperature range; applying a direct-current bias voltage and pulse voltage superposition signal, and collecting an acoustic signal generated by space charge displacement through a wide-temperature-range PVDF piezoelectric sensor module; and based on a sound velocity and sensitivity temperature calibration curve established by a pre-experiment, carrying out deconvolution processing on a sound wave signal to correct a temperature dependence error, and finally obtaining accurate space charge density distribution at different temperatures. According to the invention, the precision and reliability of space charge measurement of the solid insulating material in a wide temperature range are effectively improved.

A non-interferometric thin film lithium niobate electro-optical modulator for data transmission including a laser, configured to generate an input continuous wave light beam; a non-interferometric thin film lithium niobate modulator including an optical waveguide situated along with the coplanar transmission lines and the DC bias conductors. The propagation constant of the optical waveguide is tuned and modulated by the RF data signal and the DC bias voltage traveling on the coplanar transmission lines and the DC bias conductors. The modulator can be tuned at quadrature point by the DC bias voltage. The optical power can be modulated by the RF data signal travelling on the coplanar transmission line; a low noise RF amplifier for data signal amplification; and a bias tee for combining the data signal and DC bias voltage and send them to the coplanar transmission lines.

The application discloses an online permanent magnet flux identification method of a permanent magnet synchronous motor considering cross coupling effect and belongs to the permanent magnet flux identification technology of the permanent magnet synchronous motor. The application aims at solving the problem that the existing permanent magnet synchronous motor flux identification method does not consider the cross coupling influence of the motor, thereby causing the error of the flux observation result to be large. The application comprises the following steps: under the online stable working condition of the motor, injecting a sinusoidal current signal into the dq axis of the motor to realize three-phase direct current signal injection; calculating the motor stator resistance; injecting two groups of direct current bias voltage into the d-axis of the motor through the current loop, establishing three motor voltage equations, and then obtaining two motor voltage difference equations which eliminate the flux terms; solving to obtain the motor d-axis self-inductance L d and the motor dq-axis mutual inductance L dq ; establishing the dq-axis voltage equation considering the cross coupling, calculating the motor permanent magnet flux based on the motor stator resistance, the motor d-axis self-inductance L d and the motor dq-axis mutual inductance L dq . The application is used for the online identification of the permanent magnet flux of the permanent magnet synchronous motor.

The present application relates to the technical field of quantum precision measurement, in particular to a Roland C signal receiving method and system based on Rydberg atoms, which utilizes atomic antennas to prepare Rydberg atoms in an alkali metal atom gas chamber to obtain an electromagnetically induced transparency (EIT) spectrum; a Roland C signal reaches the alkali metal atom gas chamber through free space, and the EIT spectrum produces an oscillation peak by utilizing the Stark effect of the Rydberg atoms; the coupling laser frequency is locked to the maximum position of the oscillation peak amplitude; by applying a direct current bias voltage to the parallel electrodes built in the alkali metal atom gas chamber, on the one hand, the received Roland C signal is corrected, and on the other hand, the alternating current Stark effect is amplified, so that the receiving sensitivity of the Roland C signal is significantly improved.

The invention provides a spaceborne fiber-optic gyroscope and an on-orbit regulation and control method thereof, and relates to the technical field of fiber-optic gyroscopes, a circuit part of the spaceborne fiber-optic gyroscope comprises a signal processing unit, an optical power detection unit and an optical power regulation and control unit; the signal processing unit receives superposed signals which are output by the optical path part and contain direct-current bias voltage and high-frequency alternating-current voltage for signal conditioning, the conditioned high-frequency alternating-current voltage is converted into digital angular velocity signals, and the direct-current bias voltage is extracted from the superposed signals through the optical power detection unit. The direct-current bias voltage is amplified and converted into a digital optical power signal, the digital optical power signal and / or the digital angular velocity signal are / is sent to a satellite service computer through an optical power regulation and control unit, and the optical power regulation and control unit is further used for responding to an optical power regulation and control instruction which is forwarded by the satellite service computer and generated by a ground station. And generating a driving current to adjust the output light power of the light path part until the precision of the spaceborne fiber-optic gyroscope meets the satellite service requirement.

The application belongs to the technical field of integrated circuits, and specifically discloses a digital control programmable gain amplifier chip, which adopts an SIP packaged operational amplifier, a digital potentiometer, an input end Vin and an output end Vout, an alternating current signal is input from the Vin end, is connected to the inverting input end of the operational amplifier through a capacitor C1 and an input resistor R1, a positive power supply pin of the operational amplifier is connected to a positive electrode VDD of a power supply, a negative power supply pin is connected to the ground, a same-phase input end obtains a VDD / 2 direct current bias voltage through a precision resistor voltage dividing network and is connected after low-pass filtering, a high end of the digital potentiometer is connected to the Vout end, a low end is connected to the inverting input end of the operational amplifier, and a feedback path is formed through a sliding end. The operational amplifier and the digital potentiometer are integrated, high integration and modularization of the programmable gain amplification circuit are realized, and the problems of insufficient gain precision, decreased reliability of a multi-element system and large circuit volume caused by the on-resistance of an analog switch in a traditional discrete scheme are solved.

The application discloses a nano-channel transistor structure with an auxiliary anode and a driving method. The structure comprises an insulating substrate, a cathode, a gate and an anode which are made on the substrate, and at least one auxiliary anode is additionally arranged on the side of the anode away from the cathode. The auxiliary anode and the anode can have a height difference. By applying different direct-current voltages, a regulating electric field is formed between the anode and the auxiliary anode, the moving direction and speed of the electrons passing through the anode are changed, and the electrons are collected by the anode or directly collected by the auxiliary anode. The application also provides a corresponding driving method. The gate applies a direct-current bias voltage superimposed with a high-frequency modulation signal, and the anode and the auxiliary anode respectively apply direct-current voltages. The amplified high-frequency signals collected by the anode and / or the auxiliary anode are output through a capacitor, and the multi-output signals can be superimposed after the phase compensation system makes the phases of the multi-output signals consistent. The application effectively improves the utilization efficiency of the cathode emitted electrons and the total output current of the device.

Embodiments of the present application relate to an amplifying device and a transmitter. An amplifying device and a transmitter capable of compensating for a parasitic component of a circuit element without complicating a circuit structure are provided. The amplifying device includes a first amplifier that performs an amplifying operation on a signal; N-1 second amplifiers that perform an amplifying operation on the signal in sequence according to an amplitude of the signal in a case where the first amplifier performs the amplifying operation; N input networks connected to an input terminal that inputs the signal; N output networks connected between an output node of the first amplifier and a load connection node and connected between output nodes of the N-1 second amplifiers and the load connection node; and a first bias network that supplies a direct current bias voltage to at least one of the N output networks, an electrical length of the first bias network being less than 90 degrees.

The invention discloses a single-pole double-throw switch filtering assembly based on an LTCC (Low Temperature Co-Fired Ceramic) technology. A switching circuit and an LTCC resonator are integrated, and the on-off state of a switching diode in the working process is controlled by an externally applied direct current bias voltage. When the diode is in a conducting state, the parasitic inductor and the capacitor form series resonance, and the equivalent coupling admittance converter passing through the resonator can be inverted and equivalent to an open circuit, so that a branch signal is cut off, and channel isolation is realized; and when the diode is in a closed state, the electromagnetic field distribution of the substrate integrated waveguide resonator is not obviously influenced, the filter keeps normal work, and signal passband transmission is realized. According to the structure, on one hand, the SIW waveguide integration form is used for achieving the low insertion loss characteristic; and on the other hand, the stop-band suppression degree is effectively improved by introducing the cross coupling topology. The whole circuit has the advantages of being compact in structure, low in loss, high in isolation degree, excellent in out-of-band rejection performance and the like, and the requirements of 5G and future high-speed wireless communication systems can be met.

The invention discloses a direct-current-bias-free high-power LED visible light signal transmission method and system, and relates to the technical field of optical communication, and the method comprises the steps: carrying out 64QAM-OFDM modulation and IQ modulation on original audio and video data, carrying out AC coupling peak-to-peak value extraction and DC component filtering, and then carrying out single-power-supply amplification and pre-equalization; and a driving positive voltage signal is generated to drive a high-power LED to emit light, and an optical communication signal is generated. Through a low-loss alternating-current coupling transmission mode, the modulated real signal peak-to-peak value is subjected to coupling transmission and single positive power supply amplification, so that the signal is changed into positive voltage to control the LED light intensity and form an LED optical communication signal, direct-current voltage does not need to be introduced into a digital domain, the problem of bandwidth reduction is avoided, and the signal transmission efficiency is improved. The direct-current bias voltage of the LED can be kept stable, the LED works in a linear modulation area, bandwidth expansion is carried out through the pre-equalization circuit, and the functions of LED illumination and high-speed communication can be considered.

The invention discloses a capacitive inductive voltage sensor ultra-wideband response performance expansion circuit and a test method. According to the circuit, the ultra-wideband response capability is improved by cascading a hybrid integrating circuit, a high-pass filtering module and a voltage follower; the hybrid integrating circuit is formed by connecting a passive integrator (self-integrating to process low frequency and suppress high-frequency noise) and an active integrator (reducing high frequency in a differential mode) in series to cooperatively broaden the frequency band; the high-pass filter filters DC bias, and the voltage follower realizes impedance matching and signal isolation. Experiments prove that the hybrid voltage sensor can realize good waveform reduction on sinusoidal signals as low as 5Hz and steep waves as high as 10MHz, and the voltage division ratio is stable; for a 1kHz signal, after the circuit is inserted, the output phase is consistent with the input, the amplitude is accurately restored according to the designed voltage division ratio, the phase lead and the amplitude attenuation are effectively inhibited, the traditional frequency band limitation is broken through, and the circuit is suitable for an ultra-wideband voltage measurement scene.

The application discloses a kind of MZM array bias point control method and circuit based on high harmonic suppression, it is related to circuit control technical field, comprising the following steps: S1, generate low-frequency sinusoidal signal, after processing, load to MZM array;S2, the optical signal output to MZM array is preprocessed;S3, the optical signal after preprocessing is sampled, and the amplitude spectrum in frequency domain is obtained;S4, according to the amplitude spectrum in frequency domain, calculate harmonic ratio;S5, based on harmonic ratio, the corresponding direct-current bias voltage is output, the locking of bias point is realized.The application uses digital FFT algorithm to replace expensive analog demodulation circuit, while ensuring high performance, substantially reduce hardware cost and PCB area, conducive to engineering batch application.

A method for measuring DC bias aging characteristics of a multilayer capacitor includes applying a first poling voltage to a multilayer capacitor including a body having a dielectric layer including a plurality of dielectric grains and an internal electrode disposed alternately with the dielectric layer in a first direction, and an external electrode disposed on the body, maintaining the first poling voltage for a first period of time (t1), applying a DC bias voltage lower than the first poling voltage, maintaining the DC bias voltage for a second period of time (t2), and measuring saturated capacitance after the DC bias voltage is applied.

The application provides an E-FSR unit with an absorption and transmission mode controlled by an HPM and a direct current bias, comprising a plurality of periodically arranged E-FSR units, each unit being a five-layer cascade structure, and from top to bottom, the five-layer cascade structure is sequentially a first loss layer, a first air layer, a second loss layer, a second air layer and a frequency selection layer; the first loss layer, the second loss layer and the frequency selection layer each comprise a dielectric substrate, a metal pattern printed on the upper and lower sides of the dielectric substrate and a metal connecting column penetrating through the dielectric substrate; the frequency selection layer and the first loss layer and the second loss layer each are provided with a diode, the absorption and transmission mode is switched by applying a direct current bias voltage to the diode or driving the diode by using high-power microwave incidence, so as to meet the antenna mute stealth requirement, and the absorption and transmission mode is adaptively switched to an absorption band when high-power microwave is incident, so as to realize a protection function. The application solves the in-band strong scattering problem when the antenna is muted, has the advantages of dual-polarization characteristics, wide-band absorption and low insertion loss and the like.

The application discloses a MEMS loudspeaker device, system and preparation method driven by electrostatic and piezoelectric mixed driving, relates to the technical field of loudspeakers, and aims at solving the problems of high driving voltage, easy occurrence of suction effect and insufficient low-frequency response caused by single electrostatic driving mode of the prior art, and the problem of poor high-frequency response caused by single piezoelectric driving. The MEMS loudspeaker device comprises, from bottom to top, a substrate, an electrostatic driving unit formed on the substrate, at least a fixed electrode and a movable diaphragm of the electrostatic driving unit, and a piezoelectric driving unit integrated on the movable diaphragm. The piezoelectric driving unit receives a preset direct-current bias voltage of a preset size to control the movable diaphragm to generate a preset static displacement in the direction of the fixed electrode, and the piezoelectric driving unit processes middle-low frequency signals in input wide-band audio signals; the electrostatic driving unit processes high frequency signals in the wide-band audio signals. The application is used for improving loudspeaker quality of the loudspeaker and reducing power consumption.

The invention provides an on-line measurement method for ground capacitance current of a power distribution network, and relates to the technical field of power system measurement, and the method comprises the steps: injecting a sine AC signal at an opening triangle of an electromagnetic voltage transformer of the power distribution network; the initial phase angle of the sine alternating current signal is zero; acquiring an acquired voltage response signal generated by the bus of the power distribution network during the period of injecting the sine alternating current signal; extracting a direct current bias voltage component from the voltage response signal; determining equivalent ground capacitance of the power distribution network based on the direct current bias voltage component; and determining the total capacitance current of the power distribution network under the rated voltage based on the equivalent ground capacitance. The method can achieve the purpose of online, safe, low-cost, high-precision and high-interference-resistance ground capacitance current measurement of the power distribution network.

This invention belongs to the field of microwave communication and electromagnetic protection technology, specifically providing a fast-response limiting and filtering integrated HPM protection device based on carbon nanotube field emission, to overcome many shortcomings of the existing technology. Based on existing limiting and filtering integrated high-power microwave protection devices, this invention introduces a carbon nanotube field emission limiting structure. Through carbon nanotube field emission, high-density deterministic seed electrons are provided, significantly shortening the gas breakdown avalanche setup time, thereby significantly reducing the total response time. Simultaneously, a metal-dielectric-metal three-layer coaxial DC bias structure is designed to apply a DC bias voltage to the carbon nanotube film to modulate the field emission current density, achieving real-time control of the response speed. Ultimately, the limiting and filtering integrated high-power microwave (HPM) protection device of this invention has a faster response speed, more stable limiting performance, and the response speed can be actively controlled.

The utility model relates to the technical field of power electronics, and discloses a rotary transformer excitation circuit. The circuit comprises at least one power integrated operational amplifier unit and a direct current bias voltage unit, the power integrated operational amplifier unit comprises a signal input end, a bias voltage input end and a signal output end; the DC bias voltage unit is connected with the bias voltage input end. According to the application, the power integrated operational amplifier unit is arranged to carry out power amplification on the received excitation sinusoidal signal based on the direct current bias voltage and then output the excitation sinusoidal signal to the external main control chip, and due to the adoption of the power integrated operational amplifier design circuit, the circuit structure is simplified, the total number of devices in the circuit is reduced, and control blind spots are reduced.

The invention discloses a superfluid helium second sound wave attenuation measurement system. The system comprises a signal generation module, a transducer module, a signal conditioning module, a bias power supply module, a protection isolation module, a data processing module, a temperature control module and a pressure control module. The signal generation module outputs AC excitation signals, the transducer module converts electric signals and second sound waves mutually, the signal conditioning module extracts effective signals and outputs direct-current signals, the bias power supply module provides direct-current bias voltage, the protection isolation module guarantees equipment safety and signal isolation, and the temperature and pressure control module maintains the superfluid helium state to be stable. The data processing module supports a steady state measurement mode and a transient state measurement mode, and vortex line density is analyzed and calculated through harmonic peaks. Compared with an existing measurement system, the system is high in signal stability, standard in calibration process, suitable for various measurement scenes, convenient to operate and wide in applicability, and high-precision quantitative measurement of superfluid helium second sound wave attenuation is achieved.

The invention relates to a terahertz transmission wave modulator based on multilayer microstructure heterogeneous integration. The terahertz transmission wave modulator comprises a metal radiation layer, a substrate material, a metal ground layer, an insulating material, a direct current wiring layer, a resin material and a metal receiving layer which are sequentially arranged from top to bottom, the metal radiation layer comprises two diodes; when a terahertz incident wave of which the electric field direction is parallel to the transverse central axis of the metal receiving layer enters the metal receiving layer, a direct current bias voltage signal generated by the direct current wiring layer is transmitted to the two diodes of the metal radiation layer so as to control the conduction state switching of the two diodes; and the amplitude and phase of the terahertz transmission wave emitted by the metal radiation layer are subjected to 1-bit modulation. The terahertz modulator is diversified in regulation and control mode and excellent in performance, can play an important role in terahertz application fields such as tracking and pointing communication, radar perception and object imaging, and has a wide application prospect.

Embodiments of the disclosure describe an apparatus that includes a processing chamber having a grounded chamber shield that at least partially defines a processing region. An electrode is disposed within the processing region of the processing chamber. The electrode includes apertures extending through the electrode and the electrode is disposed between a sputtering target and a substrate. A voltage source is configured to apply a positive DC bias to the electrode. A grounded electrode shield is disposed within the processing region and extends a distance from the electrode. The distance is adjustable to vary a ratio of a surface area of the electrode to a surface area of the grounded electrode shield.

The application discloses a Mach-Zehnder modulator-based nonlinear calculation method and system, and relates to the technical field of optical fiber communication, wherein the Mach-Zehnder modulator-based nonlinear calculation method comprises the following steps: loading an optical carrier generated by a laser into an input port of a Mach-Zehnder modulator (MZM); loading a direct current bias voltage into upper and lower arms of the MZM, and loading data requiring nonlinear calculation into the upper and lower arms of the MZM as an alternating current voltage after the data are converted into an electrical analog signal; adjusting a voltage difference of the direct current bias voltage loaded into the upper and lower arms, so that the MZM is in a bias point in different states; and obtaining a nonlinear calculation result according to output optical signals of the bias points in different states of the MZM. The application utilizes different forms corresponding to different bias points of the MZM to realize the nonlinear calculation with fast response time and low energy consumption, and reduces the dependence on electrical devices.

The invention discloses a laser gyroscope based on polarization beam splitting RAM noise suppression. The laser gyroscope comprises an electro-optical modulator which converts linear polarization laser into modulated light; the half-wave plate converts the modulated light into a composite light beam; the annular resonant cavity reflects the P polarization component and the S light sideband; the polarization splitting prism transmits the S light sideband to the first photoelectric detector and transmits the P polarization component to the second photoelectric detector; the first frequency mixer adopts a radio frequency signal to carry out frequency mixing on the first AC signal to obtain a PDH locking error signal; the first servo system adjusts the laser frequency of the laser according to the PDH locking error signal; the radio frequency signal source and the second frequency mixer demodulate the second AC signal to obtain an RAM noise error signal; and the second servo system adjusts the direct current bias voltage of the electro-optical modulator according to the RAM noise error signal. Therefore, double closed-loop control of frequency locking and RAM noise suppression can be realized through a polarization separation technology.

This invention discloses a reconfigurable electromagnetic metasurface unit integrating transmission, reflection, and absorption functions. The metasurface unit includes two identical polarized resonant patches connected by a central metal via. Four positive intrinsic negative PIN diodes are integrated into the tunable patch layer, and the state of the four PIN diodes is dynamically controlled by a DC bias voltage. This invention can flexibly switch the operating mode of the metasurface by a DC bias voltage, and control the electromagnetic wavefront in real time in absorption mode (low RCS), transmission mode, and reflection mode. Through array coding, it can realize functions such as high-gain beamforming, beam scanning, beam focusing, RCS reduction, beamforming, and vortex beam generation. It has the advantages of simple design, low cost, and excellent performance, and has great potential in fields such as smart skin, electronic countermeasures, and wireless communication systems.

The application provides an electro-optical modulator, belonging to the technical field of electro-optical modulation. The electro-optical modulator comprises a Mach-Zehnder interference optical path and an electrode assembly. The Mach-Zehnder interference optical path comprises a first branch waveguide and a second branch waveguide. The electrode assembly comprises a radio frequency electrode and a direct current bias electrode. The radio frequency electrode and the direct current bias electrode are integrally formed or separately arranged. Because the first direct current bias voltage V1 and the second direct current bias voltage V2 with the same electric field direction and different voltages are respectively loaded on the first branch waveguide and the second branch waveguide, the phase change caused by the direct current drift generated on the first branch waveguide and the second branch waveguide is mutually offset after the beam combining waveguide of the Mach-Zehnder interference optical path, and the generated direct current drift is inhibited.

The application discloses a bipolar square wave excitation generation and conductivity detection circuit, a direct current bias square wave generation circuit can generate direct current bias square wave excitation signals with different frequencies; a direct current bias generation circuit generates a direct current voltage excitation; the direct current bias of the direct current bias square wave is equivalent to the size of the direct current voltage, and two signals are superposed to form a bipolar square wave excitation signal. An internal reference voltage output by an ADC is used as a voltage source of the direct current bias square wave generation circuit and the direct current bias voltage generation circuit; a node voltage of an ADC acquisition circuit is collected, so that the conductivity and temperature of a medium to be measured are obtained. The excitation and detection mode provided by the application ensures that all circuit voltages are positive voltages, simplifies the structure of the excitation and sampling circuit, is high in measurement accuracy, stable in measurement, low in power consumption and capable of meeting long-term online monitoring requirements.

A pulse current signal amplification circuit and its operating method are disclosed, comprising an APD module, a transimpedance amplifier module, an AC coupling module, and a reverse current cancellation module. The APD module is connected to the AC coupling module, the AC coupling module is connected to the transimpedance amplifier module, and the reverse current cancellation module is connected to the input and output terminals of the transimpedance amplifier module as its input terminals. To ensure that the DC bias voltage at the signal input terminal of the APD is adjustable and does not interfere with the DC bias voltage of the receiving circuit, AC coupling is used at the input. When a large signal is input, the AC coupling capacitor charges; after the signal ends, the AC coupling capacitor discharges, generating a reverse current that affects the circuit's operating state. This invention accelerates the recovery of the circuit from abnormal operating states. The reverse current cancellation circuit of this invention is configured to open an internal current path to compensate for the reverse current when the output potential of the transimpedance amplifier module is lower than that at the input terminal, thereby reducing the reverse current flowing through the transimpedance amplifier module and thus reducing the potential change at the output terminal of the transimpedance amplifier module.