25 results about "Impedance modulation" patented technology

Provided is a speaker, including: a diaphragm structure including first and second diaphragms, the first diaphragm is configured to push air to vibrate to generate initial sound wave, and a signal of which is modulated based on a signal within an audible sound frequency band; and a cover plate structure enclosing with the diaphragm structure to form sound-generating cavity, the cover plate structure has a sound outlet hole connecting the sound-generating cavity with outside, the initial sound wave in the sound-generating cavity is transmitted to the outside through the at least one sound outlet hole to form a sound signal, the second diaphragm and the cover plate structure generate an acoustic environmental impedance used to modulate the initial sound wave to change sound pressure of the sound signal. The speaker can modulate and output a sound signal covering the audible sound frequency band based on the acoustic environmental impedance.

A plasma processing system is disclosed. A very high frequency (VHF) generator delivers power to a plasma chamber, and a mid-frequency (MF) generator delivers power to the plasma chamber. The VHF generator includes a sensor configured to provide a signal indicative of an impedance of a plasma load that is presented to the VHF generator. The VHF generator further includes a frequency tuner configured to adjust a frequency of the VHF generator within a cycle of the MF generator based on the signal to mitigate impedance modulation caused by the MF generator. Impedance modulation may also be mitigated by a sync line between the VHF and MF generators that allows presetting the VHF generator frequency in synchronization with a cycle of the MF generator.

A sensor system configured to provide an indication of a sensed parameter, the sensor system comprising: a reader comprising a reader antenna configured to transmit a carrier signal; a tag comprising: a tag antenna configured to receive the carrier signal; power harvesting circuitry coupled to the tag antenna and configured to produce an operating voltage from the receiver carrier signal; the voltage-controlled oscillator, VCO, circuitry coupled to the power harvesting circuitry and configured to receive the operating voltage therefrom, wherein the VCO circuitry comprises a VCO configured to generate an output signal having a frequency which varies based on the sensed parameter, and wherein the VCO circuitry is configured to modulate an impedance of the tag antenna according to a timing parameter selected based on the frequency of the output signal from the VCO; a controller coupled to the reader antenna and configured to: (i) identify an indication of the timing parameter of the impedance modulation of the tag antenna based on detected changes in the reader antenna impedance, and (ii) determine an indication of the sensed parameter based on the identified indication of the timing parameter.

The present application provides a communication method and a communication apparatus. The method comprises: determining a first time domain symbol, wherein the first time domain symbol comprises N sub-symbols, first M sub-symbols among the N sub-symbols are null symbols, the sub-symbols following the first M sub-symbols among the N sub-symbols are periodically repeated sub-symbol sequences, and M and N are positive integers; and transmitting the first time domain symbol. On this basis, an impedance modulation transmitter can generate and transmit a first time domain symbol, and is compatible with an OFDM framework.

This application relates to an EEG signal transmission device and method based on event-driven backscattering. The device includes a neural signal input unit, an event triggering unit, an impedance modulation unit, and an antenna unit. The neural signal input unit acquires and outputs continuous analog EEG signals. The event triggering unit performs time integration on the continuous analog EEG signals and executes threshold decision to generate event pulses characterizing EEG events. The impedance modulation unit switches the load impedance state under the control of the event pulses. The antenna unit generates backscattered signals that change with the load impedance state switching under the action of an external radio frequency excitation signal. This application maps continuous neural electrical signals to event pulses and controls the load impedance switching in an event-driven manner, so that the antenna only participates in modulation when an event occurs. This achieves wireless transmission of neural information without analog-to-digital conversion and complex digital processing, significantly reducing the average power consumption of the system.

A plasma processing system is disclosed. A very high frequency (VHF) generator delivers power to a plasma chamber, and a mid-frequency (MF) generator delivers power to the plasma chamber. The VHF generator includes a sensor configured to provide a signal indicative of an impedance of a plasma load that is presented to the VHF generator. The VHF generator further includes a frequency tuner configured to adjust a frequency of the VHF generator within a cycle of the MF generator based on the signal to mitigate impedance modulation caused by the MF generator. Impedance modulation may also be mitigated by a sync line between the VHF and MF generators that allows presetting the VHF generator frequency in synchronization with a cycle of the MF generator.

The application provides an impedance modulation device and a signal receiving method, and relates to the technical field of communication.The device comprises an antenna unit, a modulation load selection unit, and a modulation load selection circuit for selecting a load unit connected with the antenna unit from a first load unit and a second load unit; wherein the impedance of the antenna unit is Za, the impedance of the first load unit is Zc1, and the impedance of the second load unit Zc2 satisfies: 0<|(Г0 / |Г0|)+(Г1 / |Г1|)|<γ, wherein represents taking an absolute value, γ is a preset threshold value, Γ0=(Zc2‑Za * ) / (Zc2+Za * ), Γ1=(Zc1‑Za * ) / (Zc1+Za * ) and the symbol is a conjugate operator.The scheme of the application can realize modulation of a backscatter signal according to a digital signal when a carrier CW signal is received at a low cost, and can be applied in a passive Internet of Things device.

The application discloses a kind of real-time monitoring impedance electric stimulation system, belong to medical electronic technical field;The system includes signal generation module, signal multiplexing module, signal acquisition module, impedance extraction module, impedance calculation module and intelligent feedback control module;Signal generation module simultaneously generates treatment stimulation signal and frequency orthogonal impedance monitoring signal;Signal multiplexing module is combined after two kinds of signals and is applied to human body by electrode;Signal acquisition module acquires mixed signal containing physiological response and impedance information;Impedance extraction module accurately extracts impedance modulation component from mixed signal using digital lock-in amplification technology;Impedance calculation module calculates electrode-tissue contact impedance in real time;Intelligent feedback control module carries out multistage threshold judgment according to impedance value, realizes alarm, parameter adjustment and safety protection function;The application realizes the synchronization of treatment and monitoring, improves the safety and reliability of system, is applicable to various electric stimulation medical equipment.

The present invention relates to the technical field of acoustic-electric conversion. Disclosed are a loudspeaker and an electronic device. The loudspeaker comprises: a diaphragm structure, the diaphragm structure comprising a first diaphragm and a second diaphragm, the first diaphragm being used for driving air to vibrate so as to emit an initial sound wave, and the signal of the initial sound wave being modulated on the basis of a signal of an audible sound frequency band; and a cover plate structure, wherein the cover plate structure and the diaphragm structure defines a sound production cavity, sound outlet holes are formed in the cover plate structure, the sound outlet holes communicate the sound production cavity with the outside, the initial sound wave in the sound production cavity is transmitted to the outside through the sound outlet holes to form a sound signal, the second diaphragm and the cover plate structure form an acoustic environment impedance, and the acoustic environment impedance is used for modulating the initial sound wave to change the sound pressure of the sound signal. The loudspeaker and the electronic device provided by the present invention can perform modulation on the basis of acoustic environment impedance, so as to output a sound signal covering an audible sound frequency band.

The invention discloses an impedance modulation antenna and an antenna beam control method and device, relates to the technical field of communication, and is used for realizing the reconfigurability of the impedance modulation antenna. The impedance modulation antenna comprises an antenna array, and each antenna unit in the antenna array comprises a transistor and metal patches arranged on the two sides of the transistor; and the feed source is arranged on the antenna array. Therefore, the impedance of the antenna can be modulated by regulating and controlling the impedance of the transistors in the different antenna units of the antenna array, so that the reconfigurability of the antenna is realized.

The invention belongs to the field of nuclear magnetic resonance logging, and particularly relates to an excitation subsystem of an in-situ split-direction imaging nuclear magnetic logging system, which comprises a four-path wide load impedance change adaptability E-type single-tube power amplifier device, a wide load impedance change adaptability four-path lossless combiner, four bridge arms, a four-path single-tube power amplifier device and a four-path lossless combiner, each bridge arm is connected with one path of wide-load impedance change adaptability E-type single-tube power amplifier device and is matched with the impedance modulation ratio of the wide-load impedance change adaptability E-type single-tube power amplifier device, and four paths of output voltages are integrated; and the controller generates an out-phase gating signal according to the out-phase modulation angle, inputs the out-phase gating signal to a gating electrode of the four-path wide load impedance change adaptability E-type single-tube power amplifier device, and adjusts the phase of the output power of the four-path wide load impedance change adaptability E-type single-tube power amplifier device according to an out-phase modulation strategy. The circuit can adapt to different load impedance conditions, and strong power output based on combination is realized.

This utility model discloses a millimeter-wave broadband impedance modulation power amplifier based on a bandpass structure, including a microwave composite board, signal input terminals VIN+ and VIN-, a first MOSFET 5XM1, a second MOSFET 5XM1, a first neutralizing capacitor CN, a second neutralizing capacitor CN, a first signal output terminal Vout-, and a second signal output terminal Vout+. The signal input terminals VIN+ and VIN- are electrically connected to the gates of the first MOSFET 5XM1 and the second MOSFET 5XM1, respectively. The two ends of the first neutralizing capacitor CN are electrically connected to the gate of the first MOSFET 5XM1 and the drain of the second MOSFET 5XM1. The two ends of the second neutralizing capacitor CN are electrically connected to the gate of the second MOSFET 5XM1 and the drain of the first MOSFET 5XM1. The first signal output terminal Vout- is electrically connected to the drain of the first MOSFET 5XM1, and the second signal output terminal Vout+ is electrically connected to the drain of the second MOSFET 5XM1. The technical solution of this utility model can achieve the goals of Ku / Ka band relative bandwidth ≥15%, 6dB backoff efficiency ≥25%, and cost reduction of more than 30%.

The present disclosure belongs to the field of nuclear magnetic resonance logging, and particularly relates to an excitation subsystem of an in-situ directional imaging nuclear magnetic logging system, which comprises: four wide-load impedance change adaptive class-E single-tube power amplifier devices, a four-way lossless combining device, four bridge arms, each bridge arm being connected with one wide-load impedance change adaptive class-E single-tube power amplifier device, and the impedance modulation ratio of the wide-load impedance change adaptive class-E single-tube power amplifier device being matched with the voltage integration of four-way output; and a controller, which generates a heterophase gate signal according to a heterophase modulation angle, and inputs the heterophase gate signal to a gate electrode of the four wide-load impedance change adaptive class-E single-tube power amplifier devices to adjust the phase of the output power of the four wide-load impedance change adaptive class-E single-tube power amplifier devices according to a heterophase modulation strategy. The present disclosure can adapt to different load impedance conditions and realize strong power output based on combining.

A system and method for hardware-interlocked identity succession utilize a hardware-rooted integrity sentinel and an analog audit engine to enforce state integrity in a 2 nm-class semiconductor. Voltage anomalies are detected via continuous-time monitoring using a differential propagation delay interferometer and an asynchronous glitch latch, and enforcement is applied by an analog impedance modulation network physically interposed on a processor signature-enable line. A vertical-stack inductive gradient sensor integrated within a BSPDN stack detects backside tamper via mutual inductance changes. An analog memristive crossbar audit engine performs stochastic challenge-response scoring, and a thermal-security via lattice stabilizes the audit engine while also providing a parallel discharge path for termination. Identity transfer is controlled by a hardware-interlocked state machine with a deadman timer that triggers zeroization absent a physical acknowledgment signal.

The application discloses a liquid cooling data center heat dissipation intelligent regulation and control method based on dynamic flow regulation, relates to the field of data center thermal management, and comprises the following steps: acquiring CPU power change data and temperature distribution data in real time; acquiring initialization flow parameters of each cooling branch; adapting and adjusting the initialization flow parameters to the temperature distribution data to generate a first group of adaptive hydraulic impedance; performing power jump prediction according to the CPU power change data, and adapting the first group of adaptive hydraulic impedance to the temperature distribution data as a starting point according to the jump prediction information to generate a second group of adaptive hydraulic impedance; and generating a digital control instruction through an impedance modulator, and issuing the digital control instruction to the opening degree of a digital potentiometer control electromagnetic flow valve of each cooling branch through a digital potentiometer control interface. The application solves the technical problem that the existing heat dissipation regulation and control cannot dynamically adjust the cooling flow according to the actual operation state of a server, and achieves the technical effect of adjusting the cooling flow in real time according to the heat dissipation demand.

The invention discloses a multichannel temperature sensor synchronous acquisition system and method for a meteorological metering system, and particularly relates to the technical field of meteorological metering and precise temperature measurement. The problem that in-phase system errors are generated due to the fact that a shared reference voltage source is modulated by common impedance due to synchronous and rapid change of sensor signals is solved; the method comprises the following steps: synchronously acquiring digital signals of multiple temperature sensors, monitoring output noise signals of a shared reference voltage source, analyzing high-frequency energy mutation of the noise signals to identify a current synchronization event, extracting reference disturbance characteristics corresponding to the event, performing spatial mode decomposition on the sensor signals during the event, performing spectral analysis on the reference disturbance, and obtaining a reference disturbance characteristic; and constructing a modal spectrum projection matrix associated with the two modes, calculating the error compensation amount of each path of sensor signal, and finally applying the compensation amount to the original data to obtain accurately compensated temperature data so as to realize effective suppression of the dynamic common-mode error.

The embodiment of the invention provides a power amplifier and a chip, the power amplifier comprises a first signal input end, a second signal input end, a first amplification link, a second amplification link and a target output end, the first amplification link comprises a first driving stage amplifier, at least one second driving stage amplifier and a first final stage amplifier; wherein the first driving stage amplifier and the at least one second driving stage amplifier are arranged in parallel. According to the implementation of the invention, the main driving branch and the auxiliary driving branch can work cooperatively, only the main branch is conducted to maintain high efficiency at low power, the auxiliary branch is started at high power, and the final-stage driving capability is enhanced through impedance modulation, so that the efficiency and the output power of a backoff point are remarkably improved.

The application provides a broadband impedance modulus index calculation method, comprising the following steps: S1, signal acquisition; S2, frequency band division; S3, calculation of sub-frequency band impedance; S4, stability index; the application breaks through the limitation of the traditional method through multi-dimensional parameter fusion and dynamic collaborative optimization; an improved wavelet packet decomposition algorithm is used to construct non-uniform frequency band division, and fine modeling of full-frequency band impedance characteristics is realized; the total impedance modulus is synthesized by fusing the regularization constraint, the sub-frequency band impedance and the phase data; the peak values of the total impedance modulus, the stability margin and the total impedance modulus curve are fused dynamically to construct a multi-dimensional stability evaluation model; and the multi-level response strategy is triggered based on the fusion index.

The application discloses a holographic metamaterial array antenna applied to an RFID reader-writer, which comprises an impedance modulation unit area and a planar monopole area, wherein the impedance modulation unit area is formed by periodically arranging impedance modulation units in a rectangular shape, the impedance modulation unit comprises at least two layers of rectangular metal patch layers and at least two layers of rectangular dielectric layers and is located above a layer of rectangular metal ground plate layers, and the rectangular metal patch layer farthest from the rectangular metal ground plate layer has a slit structure; the planar monopole area is arranged at a central position of the holographic metamaterial array antenna, the planar monopole area comprises a planar monopole, at least one layer of rectangular dielectric layers and a layer of rectangular metal ground plate layers, wherein the planar monopole is located at the same layer as the rectangular metal patch layer; and the thickness of the planar monopole area is less than or equal to the thickness of the impedance modulation unit area. The application has clear working area boundaries, can realize a powerful working area field type and uniform coverage, and further improves reading effect.

A phase-switched impedance modulation (PSIM) system for use within a tunable matching network is provided herein. The system comprises a primary port configured to receive an RF signal, at least one transformer having a primary side and a secondary side, wherein the primary port is connected to the at least one transformer at the primary side thereof, at least one submodule comprising a plurality of reactive elements coupled to the at least one transformer, a switch connected to each of plurality of reactive elements, and a controller configured to generate control signals for the plurality of switches to modulate an effective reactance seen at the primary port by controlling at least one selected from the group consisting of a duty cycle and a phase of each of the plurality of switches.

Dynamic impedance modulation in a power management circuit is provided. The power management circuit, which includes a power management integrated circuit (PMIC) and a power amplifier circuit, is configured to amplify a radio frequency (RF) signal for transmission. Herein, the PMIC is configured to generate a supply voltage in accordance with a time-variant power envelope of the RF signal and the power amplifier circuit is configured to amplify the RF signal based on the supply voltage. Specifically, an impedance modulation circuit is provided in the power amplifier circuit and configured according to various embodiments to perform a load modulation when an instantaneous power level of the RF signal falls within a defined power range. As a result, it is possible to reduce a dynamic voltage range (e.g., peak-to-peak voltage range) of the supply voltage to help improve efficiency of the power management circuit.

The invention relates to a synchronous rectification simulation backflow solving method, which relates to the technical field of synchronous rectification, and comprises the following steps: step 1, backflow risk pre-judgment: at a turn-off decision moment of a synchronous rectification switch tube, synchronously detecting instantaneous values of drain-source voltage Vds and flowing current Ids of the synchronous rectification switch tube, and judging a backflow risk of the synchronous rectification switch tube according to the instantaneous values of the drain-source voltage Vds and the flowing current Ids; if the conditions that the Vds is lower than a preset low-voltage threshold value and the Ids is higher than a preset current threshold value are met, it is judged that a high backward flow risk scene exists, pre-turn-off impedance modulation is started immediately, the modulation depth is enhanced in a self-adaptive mode, and otherwise, conventional turn-off logic is executed. According to the invention, through linkage of risk pre-judgment and pre-turn-off impedance modulation, the switching tube is arranged in a critical conduction region at the initial turn-off stage, so that the conduction resistance of the switching tube is naturally increased, the current change rate is mildly limited, violent voltage recoil and ringing caused by sudden current change are avoided from the source, and the switching tube is effectively protected.

Provided are a communication method and a communication device, the method comprising: determining a first time domain symbol, the first time domain symbol comprising N sub-symbols, the first M sub-symbols of the N sub-symbols being null symbols, the sub-symbols after the first M sub-symbols of the N sub-symbols being a periodically repeated sub-symbol sequence, and M and N being positive integers; and sending the first time domain symbol. Based on this, the impedance modulation transmitter can generate and transmit a first time domain symbol, while being compatible with an OFDM framework.