8results about How to "Lower input impedance" patented technology

The invention discloses an electronic circuit and a control method for improving electromagnetic ultrasonic transmitting power and receiving efficiency, an electromagnetic ultrasonic transducer adopts N sub-coils as an integral mother coil, and when high voltage is transmitted, the N sub-coils are connected in parallel by using the electronic circuit and are connected to a high-voltage power supply output network; when a signal is received, the electronic circuit connects the N sub-coils in series to form a large coil for receiving an electromagnetic ultrasonic echo signal so as to enhance an electromotive force signal received in the coil. According to the control circuit, the impedance of the transducer is reduced during high-voltage emission, the power of a power supply obtained by the transducer is improved, an ultrasonic echo signal output by the transducer is increased during receiving, differential symmetric output of a transducer signal is realized, common-mode noise of the transducer is suppressed, and the signal-to-noise ratio of a received signal is improved. The problem that the signal-to-noise ratio of electromagnetic ultrasonic echo signals is not high due to the fact that the conversion efficiency of the same transducer is difficult to further improve on the basis of an existing electromagnetic ultrasonic technology is solved.

The present invention discloses an ultra-low frequency integrated receiving device, which belongs to the field of wireless communication technology. The device of the present invention comprises a preamplifier module, a small signal amplification module, a large signal amplification module, an AD sampling module and a main control module which are electrically connected in sequence; the preamplifier module performs low-noise amplification and low-pass filtering on the input signal; the small signal amplification module performs ultra-low frequency bandpass filtering, a first program-controlled amplification and a power frequency trap on the input signal; the large signal amplification module performs a second program-controlled amplification, program-controlled attenuation, a second power frequency trap and an ultra-low frequency low-pass filtering on the input signal; then the signal is divided into two paths, one path is amplified and then sent to the AD sampling module, and the other path is sent to the main control module after effective value detection; the AD sampling module performs analog-to-digital conversion and down-conversion processing on the input signal; the main control module controls and manages the receiving device; the receiving device of the present invention can realize stable and reliable gain amplification of ultra-low frequency signals.

The invention discloses a centralized control type high-voltage isolating switch electric operating mechanism, and belongs to the field of high-voltage isolating switch electric operating mechanisms. Comprising an electrical control module and a motor auxiliary switch circuit which are separately arranged, the motor auxiliary switch circuit is reserved and arranged in a mechanism box of the electric operating mechanism, the mechanism box is located outdoors, the electrical control module is arranged in a control cabinet of the high-voltage isolating switch, the control cabinet is located indoors, and the motor auxiliary switch circuit is arranged in the control cabinet. The electrical control module is connected with the motor auxiliary switch circuit through a multi-core cable, and motor operation control and opening and closing position signal transmission of the electric operating mechanism multiplex the multi-core cable. The intelligent module has the advantages that the possibility that the intelligent module is serially connected with strong electromagnetic interference can be completely eradicated, and the problems of safety and reliability of the intelligent module possibly existing under the condition of strong electromagnetic interference are solved.

The invention discloses a preparation method of a high-gain photoelectric detector, and relates to the technical field of photoelectric detectors, and the method comprises the steps: S1, structural design: selecting a corresponding photoelectric material to manufacture an avalanche photodiode according to the application scene requirements and the working environment of the detector, the method comprises the following steps: S1, preparing a semiconductor wafer, S2, preparing the wafer, namely cleaning the semiconductor wafer by using an ultrasonic cleaning agent and a chemical solution, S3, treating the material, namely performing doping operation, and injecting ions containing phosphorus and boron elements into a semiconductor material by using an ion accelerator, S4, performing gain optimization, namely optimizing a circuit by using a Cascode technology, connecting circuits of two transistors, and performing gain optimization. S5, packaging and integrating: packaging the manufactured chip into a shell; according to the photoelectric detector, the circuit of the semiconductor is optimized by using a Cascode technology, the gain of the photoelectric detector can be improved by adjusting the bias voltage of the circuit, configuring the gain circuit and processing external signals, and meanwhile, the influence on output impedance is reduced, so that the high-frequency performance and the linearity of the whole circuit are improved.

The invention discloses an input current compensation circuit, an operational amplifier, a chip and an input current compensation method, and the input current compensation circuit comprises a current copying circuit and two compensation circuits. The current copying circuit is used for accessing a power supply voltage and a bias signal and generating a first current and a second current according to the bias signal and the power supply voltage; the compensating circuit is used for mirroring the first current so as to output a mirrored current of the first current to a first input end of the operational amplifier; the other compensation circuit is used for mirroring the second current so as to output the mirrored current of the second current to the second input end of the operational amplifier. According to the operational amplifier, the input current of the operational amplifier is sampled through the input current compensation circuit, and the compensation current input to the operational amplifier is generated, so that the input current of the operational amplifier is reduced or even eliminated, the input impedance of the operational amplifier is reduced, and the application range of the operational amplifier is widened.

The invention discloses a low noise amplifier for a nuclear magnetic resonance radio frequency receiving system, and relates to the technical field of amplifiers. Comprising two cascaded common-source amplifier circuits, the two stages of the common-source amplifier circuits are realized based on an ATF54143 transistor and a BGA616 amplifier respectively, and the common-source amplifier circuits comprise an input matching circuit, an inter-stage matching circuit, an output matching circuit, an output attenuation circuit, an input phase shift circuit and a single-power-supply direct-current biasing circuit; the low-noise amplifier has ultra-low input impedance, and the input impedance at a working center frequency point 64MHz is only 0.003-j * 0.263 which is far lower than the standard, so that the performance effect is excellent; according to the invention, the output noise is extremely low, the performance is more excellent under the working frequency band, the sensitivity is extremely high, the device is suitable for an MR I system and can reach-130dBm, and the whole structure is simple and reliable and is easy to realize.

The utility model discloses a kind of dual-path voice simultaneous transmission wireless transceiving systems, including transmitting part and receiving part, the transmitting part includes sequentially connected low-frequency amplification circuit, frequency synthesis oscillation circuit, resonant hybrid circuit and impedance matching transmitting circuit, the receiving part includes sequentially connected signal receiving circuit, frequency modulation circuit, mixing frequency discriminator circuit and power amplifier circuit, the impedance matching transmitting circuit is connected with the signal receiving circuit communication, the low-frequency amplification circuit receives dual-path voice input signal, the power amplifier circuit outputs dual-path voice signal;The utility model is characterized in that: the immediacy of communication is higher.

The present disclosure provides a terahertz wave imaging system and method, the system comprising: a terahertz detector (A) for detecting a terahertz modulated light signal and sampling the terahertz modulated light signal by using a demodulation signal to obtain a sampling signal; a CSA integration module (B) for sequentially integrating and amplifying the sampling signal to obtain a photocurrent signal; a signal processing module (C) for processing the photocurrent signal to obtain a sampling value, calculating the time of flight and depth information of the terahertz modulated light signal according to the sampling value, and imaging by using the time of flight and depth information; wherein the demodulation signal has a phase offset with the terahertz modulated light signal. The terahertz wave imaging system of the present disclosure can be made on the same CMOS chip, has simple design principle, high precision, low cost, and is easy to mass integrate.