56 results about "Low gain" patented technology

The invention relates to the field of aeronautical material detection, and discloses an aeronautical material detection method and system.The method comprises the steps that an ultrasonic detection signal is obtained, and frequency characteristic analysis is conducted on the ultrasonic detection signal to obtain a frequency spectrum; based on the frequency spectrum, the system can judge the source information of the ultrasonic detection signals, so that the ultrasonic detection signals with background tendency and the ultrasonic detection signals with defect tendency are distinguished; aiming at signals from different sources, the invention innovatively adopts a differential gain processing strategy: low gain is applied to the signals with background tendency to effectively inhibit the intensity of the signals; high gain is applied to signals with defect tendency so as to ensure that even weak real defect signals can be fully amplified and identified; performing defect judgment on the ultrasonic detection signal subjected to gain processing; the problems that misjudgment is introduced by the signal gain compensation module due to probe sensitivity attenuation and normal background signals and real defect signals are difficult to distinguish can be effectively solved.

The invention provides a dual-conversion gain reading circuit, a reading method and an image sensor, and the circuit comprises a comparison module which carries out the pre-comparison of a high-gain photosensitive signal and a ramp signal, so as to obtain a pre-comparison result, comparing the low-gain reset signal, the high-gain reset signal, the high-gain photosensitive signal and the low-gain photosensitive signal with a ramp signal to output corresponding comparison signals; and the counting module selects a counting mode according to the pre-comparison result to count the comparison signals so as to output data signals. A comparison module is used for pre-comparing a high-gain photosensitive signal with a ramp signal, and a counting module is used for selecting a corresponding counting mode for counting quantization according to a pre-comparison result, so that the corresponding counting mode can be adaptively selected according to a voltage difference value between a high-gain reset signal and the high-gain photosensitive signal; therefore, the dynamic power consumption of the counting module is effectively reduced, the overall power consumption of the reading circuit is reduced, and the problem that an existing dual-conversion gain reading circuit is large in dynamic power consumption is solved.

The application discloses a terahertz biological tissue imaging system and method based on a metasurface antenna. The terahertz biological tissue imaging system comprises a terahertz signal generator, an intelligent system control device, a terahertz signal transmitter and a data acquisition module. The terahertz signal generator is used for generating an ultra-wideband terahertz wave signal. The intelligent system control device controls the terahertz signal generator to continuously generate the ultra-wideband terahertz wave signal. The terahertz signal transmitter is used for transmitting the ultra-wideband terahertz wave signal after programmable modulation to a biological tissue organ. The terahertz signal receiver is used for receiving terahertz biological signals scattered inside and around the biological tissue organ, and modulating the received terahertz biological signals. The data acquisition module is used for acquiring the terahertz biological signals. The intelligent sensing signal processing module is used for processing the terahertz biological signals to obtain a terahertz image of the biological tissue organ. The application solves the problems of narrow bandwidth and low gain in the corresponding technology.

The application discloses an image sensor readout circuit, an image sensor and a working method thereof, and belongs to the field of sensors. A switch selection circuit is connected with a pixel circuit of the image sensor. In a first state, a slope voltage is connected to a first node, and a reset signal and an image signal output by the pixel circuit under high conversion gain are connected to a second node in sequence. In a second state, the slope voltage and a coupling signal of the reset signal or the image signal output by the pixel circuit under low conversion gain are connected to the first node, and a reference voltage is connected to the second node. An analog-to-digital conversion circuit quantizes the high-gain reset signal and the high-gain image signal to obtain effective image signal quantization values under high gain, and quantizes the low-gain reset signal and the low-gain image signal to obtain effective image signal quantization values under low gain. While realizing high dynamic range of the image sensor, the cost is reduced and the volume is reduced.

The invention relates to the field of integrated circuit design, in particular to a burst mode trans-impedance amplifier circuit for a 50G PON (Passive Optical Network), which comprises a high-frequency signal main circuit and a quick response auxiliary circuit, and the high-frequency signal main circuit realizes high-sensitivity amplification of low-optical-power signals and low-gain amplification of high-optical-power signals through the variable-gain transimpedance-stage amplification circuit and the amplitude-limiting post-stage amplification circuit. The quick response auxiliary circuit realizes ordered quick gain control and quick direct current bias elimination through a quick average value detection circuit controlled by different reset signals generated by the two circuits, and realizes quick response to burst signals together with the high-frequency signal main circuit. The device has the characteristics of high bandwidth, quick response and the like, can stably convert and amplify 50Gbps burst signals, and is suitable for a 50G PON uplink burst mode optical receiver system.

This invention provides a real-time hardware high dynamic range (HDR) synthesis method and camera with dual-gain grayscale characteristics, relating to the field of optical imaging technology. The method acquires dual-gain image data using a deployed sensor with high and low gain channels; performs noise suppression processing on the acquired dual-gain image data and non-uniformity correction to obtain preprocessed image data; fuses the high-gain and low-gain images into a HDR image through image fusion, and enhances the image signal-to-noise ratio and readout speed by merging adjacent pixels; verifies the dynamic range, image quality, and processing speed of the synthesized HDR image through actual shooting tests. This invention provides a dual-gain channel foundation for HDR synthesis by simultaneously outputting high-brightness and low-brightness images through the sensor's multi-gain channels. By synthesizing images with different gains, the dynamic range of the image can be significantly improved while maintaining image detail and quality.

The invention relates to a D-band high-integration multi-channel transceiver assembly, the upper surface of a feed unit is provided with a plurality of bonding pad arrays used for flip-chip bonding connection with a radio frequency chip, and each bonding pad array corresponds to a transmitting / receiving channel and is connected to a coplanar waveguide port starting from the layer; the CPWG-SIW transition structure starts from a coplanar waveguide port, and signals are transmitted to a port of the SIW first vertical transition structure in the same layer; the SIW first vertical transition structure starts from a port of the SIW first vertical transition structure, a signal is transmitted downwards to the SIW second transmission line through the SIW first vertical transition structure, after phase adjustment of the SIW second transmission line, the signal is transmitted upwards to the SIW third transmission line, the SIW third transmission line ends in an SIW resonant cavity of the antenna unit, signal energy excites a resonant field in the SIW resonant cavity, and the signal energy is transmitted to the SIW second transmission line through the SIW first vertical transition structure. And the radiation is effectively radiated into the free space through the radiation gap. The targets of feed network broadband matching, low signal transmission loss, low antenna radiation sidelobe and high gain are achieved.

The invention discloses an avalanche photodetector structure with an adjustable receiving rate and an avalanche photodetector thereof, the avalanche photodetector structure comprises an APD, the APD is composed of a positive electrode layer, an absorption layer, a gain layer, a substrate layer and a negative electrode layer, the gain layer comprises a charge control region and an avalanche multiplication region, and the negative electrode layer only comprises a negative electrode; the amplifier further comprises a plurality of multiplication control regions, at least one added avalanche multiplication region and a negative electrode added corresponding to the avalanche multiplication region, the multiplication control regions and the added avalanche multiplication region are located in the gain layer, the avalanche multiplication regions are arranged independently, the negative electrodes are arranged independently, and the multiplication control regions, the avalanche multiplication regions and the negative electrodes are arranged in a one-to-one correspondence mode; the multiplication control region and the charge control region act independently or jointly to realize regulation and control of two or more avalanche multiplication regions. The APD has the advantages that the APD gain can be adjusted in a large range, two-gear adjustment of low bandwidth and high gain and high bandwidth and low gain is achieved, and the APD can be used for receiving optical signals with different rates.

The technology described herein is directed towards remotely controlling the direction and the signal strength of a beam reflected from a reconfigurable intelligent surface. A modular design of interconnected, communicatively coupled fundamental modules of unit cells facilitates a straightforward assembly process in which the aperture of the reconfigurable intelligent surface can be scaled by tiling together the modules. The reconfigurable intelligent surface aperture can be remotely fine-tuned with respect to gain and beam reflection direction upon receiving a control signal (e.g., a nine-bit digital code through infrared). Depending on a given scenario, the reflected beam be controlled to reflect an electromagnetic wave (e.g., mmWave) as a concentrated, high-gain coverage beam in a specified direction, a more expansive, low-gain coverage area beam in the specified direction, or something in between, e.g., medium signal strength and medium coverage area.

The invention discloses a high-dynamic-range imaging CMOS camera based on a K7 gigabit network. The high-dynamic-range imaging CMOS camera comprises a camera shell 9, and a high-dynamic-range imaging CMOS camera body is installed in the camera shell 9. The CMOS camera body comprises a CMOS sensor chip 1, an FPGA (Field Programmable Gate Array) programmable logic device 2, a DDR3 (Double Data Rate 3) high-speed memory 3, a FLASH memory chip 4, a gigabit Ethernet interface 5, a GPIO (General Purpose Input / Output) isolation interface 6 and a power supply module 7. The FPGA chip receives high-gain and low-gain 2048 * 2048 resolution image data from the CMOS sensor chip at the same time, data caching is carried out through the DDR3 high-speed memory, high-dynamic-range image synthesis is completed in real time, images with 46 frames per second (the resolution is 2048 * 2048) and the dynamic range reaching 70.3 dB are output through the gigabit Ethernet interface, and working parameters of the camera can be configured through a computer.

The invention provides a radio frequency power amplifier circuit, a radio frequency front-end chip and a radio frequency front-end module, and relates to the technical field of radio frequency power amplifiers. In the first gain mode, the biasing circuit can control all transistors in all power amplifiers to be switched on; and in the second gain mode, the biasing circuit can control all transistors between the cascade output ports and the grounding end in all the multiplexing power amplifiers to be switched on, and the switching circuit can control cascade connection among all the multiplexing power amplifiers and output a target radio frequency signal through the output matching circuit. Therefore, a high-gain first gain mode is realized by controlling all the transistors in all the cascaded power amplifiers to work, and a low-gain second gain mode is realized by controlling part of the transistors in the multiplexing power amplifiers to work, so that multi-gain mode work of the radio frequency power amplifier circuit is realized; the radio frequency power amplifier circuit is prevented from working in a deep rollback state, and high efficiency of the radio frequency power amplifier circuit in different gain modes is ensured.

The application relates to the technical field of ground penetrating radar antennas, and discloses an ultra-wideband high-gain Vivaldi antenna loaded with wave-absorbing materials, which comprises a dielectric substrate with a feeding end and a radiating end arranged oppositely and comprising a first plate surface and a second plate surface arranged oppositely; an antenna radiator arranged on the first plate surface and having two radiation arms, the two radiation arms each having a first radiation arm surface facing each other, the two first radiation arm surfaces extending in a direction away from each other from the feeding end to the radiating end so that a gradually expanding groove is formed between the two first radiation arm surfaces; a circular matching groove is arranged on the antenna radiator and close to the feeding end; a wave-absorbing module is arranged on each side end of the two radiation arms away from each other; a metal director is arranged on the first plate surface and located at the radiating end; a reflector is internally provided with a reflection cavity, at least part of the feeding end is inserted into the reflection cavity, and a spacing is formed between the feeding end and the side wall of the reflection cavity. The Vivaldi antenna can alleviate the defects of low gain at low frequency, insufficient impedance bandwidth and low front-to-back ratio of the conventional Vivaldi antenna.

The application discloses a variable gain amplifier applied to a high-speed optical receiver, comprising a high gain stage, a low gain stage and a common gain load; the high gain stage comprises a high differential input pair tube and a high gain adjusting tube group connected in sequence; the common gain load is connected to the output ends of the high gain stage and the low gain stage simultaneously and is used for synthesizing the output currents of the high gain stage and the low gain stage into an output voltage; the high gain adjusting tube group has a gain adjusting voltage V ctrl1 ; the low gain adjusting tube group has a gain adjusting voltage V ctrl2 ; by independently controlling V ctrl1 and V ctrl2 , the total gain and the linearity of the amplifier can be adjusted coordinately. The application adopts the high gain stage and the low gain stage to control the circuit gain, the high gain stage provides higher gain for the circuit, and the low gain stage provides better linearity for the circuit, so that the circuit can realize high gain, and the linearity and the gain change range of the circuit are improved.

An aspect of the disclosure relates to a method of reducing a third-order intermodulation component at a first terminal of a transistor, including: receiving an input radio frequency (RF) signal cycling with a first frequency at a control terminal of the transistor; generating a feedback RF signal cycling at a second frequency at a second terminal of the transistor, wherein the second frequency is substantially twice the first frequency; and generating a third-order intermodulation cancellation component at the first terminal including combining the input RF signal with the feedback RF signal, wherein the third-order intermodulation cancellation component has a magnitude and phase substantially equal to and opposite a magnitude and phase of the third-order intermodulation component at the first terminal of the transistor, respectively.

The present application relates to a kind of high dynamic range image fusion method and device of ToF system.The present application judges whether the four phase data of high gain / long exposure time image are all luminance non-saturation first, if all are luminance non-saturation, then high gain / long exposure time image is used to carry out luminance calculation, otherwise low gain / short exposure time image is used to carry out luminance calculation, can only need to calculate the image of ToF system infrared thermal imager, need not simultaneously calculate two images, save the ToF system MCU operation time, can quickly carry out high dynamic range image fusion, can increase the dynamic range of ToF system infrared thermal imager image, avoid the phenomenon that only use low gain / short exposure time image causes the noise of image to be large, improve the image quality of ToF system infrared thermal imager.

Disclosed are a high-linearity low-noise amplifier, a chip, and an electronic device. The low-noise amplifier comprises a primary-stage amplification unit, at least one secondary-stage amplification unit, a drive unit, a configurable load unit, an input impedance matching unit and an output impedance matching unit, and further comprises a switched capacitor branch; wherein the input end of the at least one secondary-stage amplification unit is connected via the switched capacitor branch to the input end of the primary-stage amplification unit, and the input end of the secondary-stage amplification unit is provided with an independent bias voltage; in a low-gain operating mode, the switched capacitor branch is closed, and at the same time, a secondary amplification unit path connected to the switched capacitor branch is opened.

The technology described herein involves remotely controlling the direction and signal strength of beams reflected from a reconfigurable smart surface. A modular design of interconnected, communicatively coupled building blocks in a cell facilitates a simple assembly process, where the aperture of the reconfigurable smart surface can be scaled by tiling the blocks together. Upon receiving a control signal (e.g., a nine-digit code over infrared), the reconfigurable smart surface aperture can be remotely fine-tuned with respect to gain and beam reflection direction. Depending on a given scenario, the reflected beams can be controlled to reflect electromagnetic waves (e.g., millimeter waves) as concentrated high-gain coverage beams in a specified direction, more extensive low-gain coverage area beams in a specified direction, or some beams in between, e.g., moderate signal strength and medium coverage area.

The application discloses an image sensor readout circuit, an image sensor and a working method thereof, and belongs to the field of sensors. An amplifier circuit amplifies and inverts a low-gain image signal and a low-gain reset signal to output an inverted low-gain amplified image signal and an inverted low-gain amplified reset signal. A switch selection circuit sequentially outputs a high-gain reset signal and a high-gain image signal according to a first control signal, and sequentially outputs the inverted low-gain amplified image signal and the inverted low-gain amplified reset signal according to a second control signal. An analog-to-digital conversion circuit quantizes the high-gain reset signal and the high-gain image signal to obtain high-gain effective image signal quantization values, and quantizes the inverted low-gain amplified image signal and the inverted low-gain amplified reset signal to obtain low-gain effective image signal quantization values. The application realizes a high dynamic range of the image sensor, saves hardware cost, reduces the volume and improves the readout speed.

The embodiment of the invention discloses a wide-range pre-amplification circuit with a temperature compensation function and photoelectric detection equipment. The wide-range pre-amplification circuit comprises a cross-group amplification module, a filtering module and a logarithmic amplification module which are connected in sequence; for a weak light current signal in a large dynamic range, a transimpedance amplification module is designed by using an operational amplifier to carry out I / V conversion circuit, so that signal distortion caused by parasitic capacitance and gain resistance of a photoelectric conversion device is avoided; a logarithmic amplification module and a temperature compensation module designed by using a cut-off and amplification region of a triode are used for performing piecewise linear amplification on a voltage signal output by a transimpedance amplification module, high gain is used for amplifying when a small signal is input, and low gain is used for amplifying when a large signal is input so as to meet the input range of a high-precision ADC; the problem of high-precision measurement of wide-range weak signals is solved, and the temperature stability of the double-slope logarithmic amplification circuit is improved by utilizing the temperature compensation module.

This invention discloses an avalanche photodetector structure with adjustable receiving rate and the avalanche photodetector thereof, including an APD. The APD is composed of a positive electrode layer, an absorption layer, a gain layer, a substrate layer, and a negative electrode layer. The gain layer includes a charge control region and an avalanche multiplication region, and the negative electrode layer includes only one negative electrode. It also includes multiple multiplication control regions, at least one additional avalanche multiplication region, and a corresponding additional negative electrode. The multiplication control regions and the additional avalanche multiplication region are all located within the gain layer. The avalanche multiplication regions and the negative electrodes are independently configured, and the multiplication control regions, avalanche multiplication regions, and negative electrodes are configured in a one-to-one correspondence. The multiplication control regions and the charge control regions can act individually or jointly to achieve modulation of two or more avalanche multiplication regions. Advantages: The gain of the APD of this invention can be adjusted over a wide range, achieving two levels of adjustment: low bandwidth high gain and high bandwidth low gain, which can be used to receive optical signals at different rates.

The application discloses a marine beam reconfigurable ultra-short wave communication antenna, which comprises a metal connecting frame, a plurality of metal reflecting plates, a plurality of wideband dipole radiators, a wideband matching network and a beam reconfigurable network. The metal connecting frame is sleeved and fixed on the circumferential side of a columnar installation main shaft outside a ship, and the plurality of metal reflecting plates are arranged uniformly around the outer side of the metal connecting frame. The plurality of wideband dipole radiators are arranged in groups in one-to-one correspondence with the plurality of metal reflecting plates, the metal reflecting plates and the wideband dipole radiators in the same group are connected through insulating supports, and the metal reflecting plates and the wideband dipole radiators in the same group are electrically connected through the wideband matching network. The beam reconfigurable network is electrically connected with the plurality of wideband dipole radiators and is used for controlling the opening / closing state of each wideband dipole radiator according to a control signal. The antenna realizes the reconfigurable switching of the omnidirectional low-gain and directional high-gain radiation pattern through the beam reconfigurable network, and gives consideration to the omnidirectional communication coverage and the directional communication distance improvement.

This invention relates to the field of analog front-end technology and discloses a multi-channel high common-mode rejection ratio (CMRR) signal acquisition system based on idle-phase common-mode cancellation technology. The system includes: a multi-channel presampler based on a floating dynamic operational amplifier and idle-phase common-mode cancellation technology, used to sample weak input signals. Simultaneously, the output signal is periodically short-circuited during idle phases at the presampler's output to eliminate common-mode signals and improve the CMRR; a multi-channel noise-shaping successive approximation analog-to-digital converter (ADC), which takes the weak signal acquired by the presampler as input and outputs a digital signal; and an ADC that provides a time-division multiplexed clock to drive the presampler, achieving phase-synchronized clock control. The presampler technology based on idle-phase common-mode cancellation proposed in this invention has advantages such as low power consumption and high CMRR, and is suitable for low-gain multi-channel neural signal acquisition systems, effectively eliminating common-mode interference during neural signal acquisition.

The application discloses a gain optical fiber which is composed of small numerical aperture and high doping concentration fiber sections and large numerical aperture and low doping concentration fiber sections which are alternately distributed in sequence. The small numerical aperture and high doping concentration sections of the gain optical fiber are used to restrain the generation of high-order modes, and the high gain makes the fundamental mode laser amplification. The large numerical aperture and low doping concentration sections of the gain optical fiber amplify the laser power, but generate low gain to the high-order modes, so that the generation and amplification of the high-order modes can be effectively restrained, the high-quality laser output is realized, the mode instability threshold is improved, and a new technical means is provided for further realizing high-power fiber laser output.

The present application relates to the field of infrared thermal imaging technology, and discloses an infrared image enhancement and pseudo-color mapping method and system for fire fighting, equipment and a storage medium. The method and system can effectively solve the problem of insufficient contrast of infrared images in low gain mode, and through scene adaptive dynamic segmentation processing, the details of high and low temperature regions are respectively optimized, and the temperature information is converted into intuitive color warning by using the pseudo-color mapping with uniform perception, which has strong scene adaptation capability, realizes real-time, adaptive and intuitive enhancement of infrared images in extreme fire environment, and effectively supports fire rescue decision-making.

This invention discloses a high-power, multi-segment, transmission-filtered vertical-plane emitting laser, comprising: a substrate; a DBR (Diverterless Laser Reflector) unit disposed on the substrate surface; a laser gain unit and a transmission-filtering unit disposed on the side of the reflector unit away from the substrate, wherein the laser gain unit and the transmission-filtering unit are stacked adjacently and alternately to form a multi-segment structure, the stacking direction being perpendicular to the substrate; each laser gain unit emits laser light after being powered on, the laser light emitted in the direction away from the reflector unit passes through multiple transmission-filtering units before being output, and the laser light emitted towards the reflector unit is reflected by the reflector unit and then passes through multiple transmission-filtering units before being output. This invention adopts an incident laser structure with a single DBR, long cavity, multiple segments, high gain, narrow spectral line, filtering, low reflectivity at the output end, and high power structure design, solving the problems of traditional VCSELs with two DBRs, short cavity, low gain, wide spectral line, high reflectivity and low transmission at the output end DBR, and low power.

This utility model discloses a 4G rod antenna, including an antenna housing and an RF coaxial cable. A PCB board is housed inside the antenna housing, and the PCB board contains a radiator, a tapered microstrip transmission line, and a choke sleeve. One end of the tapered microstrip transmission line is connected to the radiator, and the other end is electrically connected to the core pad of the RF coaxial cable. The tapered microstrip transmission line is located inside the choke sleeve, which is electrically connected to the ground pad of the RF coaxial cable. The radiator is configured to operate in the following three frequency bands: in the first band (824MHz to 960MHz), the average gain is not less than 1.47dBi; in the second band (1710MHz to 2170MHz), the average gain is not less than 4.79dBi; and in the third band (2300MHz to 2700MHz), the average gain is not less than 3.37dBi. This solves the problems of low gain and poor radiation efficiency of existing 4G antennas in multiple frequency bands.

The application relates to the field of aviation material detection, and discloses an aviation material detection method and system. The method obtains an ultrasonic detection signal, and performs frequency characteristic analysis on the ultrasonic detection signal to obtain a frequency spectrum. Based on the frequency spectrum, the system can judge the source information of the ultrasonic detection signal, thereby distinguishing background-tendency ultrasonic detection signals and defect-tendency ultrasonic detection signals. For signals of different sources, the application innovatively adopts a differentiated gain processing strategy. Low gain is applied to the background-tendency signals to effectively suppress the intensity of the background-tendency signals. High gain is applied to the defect-tendency signals to ensure that even weak real defect signals can be fully amplified and recognized. The gain-processed ultrasonic detection signals are subjected to defect determination. The application can effectively solve the problems of misjudgment caused by a signal gain compensation module due to probe sensitivity attenuation and difficulty in distinguishing normal background signals from real defect signals.

An imaging sensor (60) includes a first circuit (62) and a second circuit (64). The first circuit (62) acquires first pixel data and outputs the first pixel data from the imaging sensor (60) as conventionally processed image data, wherein the first pixel data is data of conventional gain pixels. The second circuit (64) acquires second pixel data and performs normalization processing on the second pixel data to obtain first normalized pixel data, wherein the second pixel data is data of low gain pixels; if the conventionally processed image data is not saturated, the first normalized pixel data is output from the imaging sensor (60) as conventionally processed image data, and if the conventionally processed image data is saturated, the second normalized pixel data is clipped from the first normalized pixel data and output from the imaging sensor (60) as conventionally processed image data.

Embodiments of the present disclosure relate to a method of reading pixels with charge / voltage dual conversion gains and a corresponding system. The mode control signal places the pixel in a high conversion gain (HCG) mode or a low conversion gain (LCG) mode. A conversion operation for a pixel includes: resetting a read node of a pixel placed in an LCG mode; subsequently, a first transition is made to the mode control signal to place the pixel in an HCG mode; then performing a first charge transfer from the photodiode to the read node with HCG; then performing a second transition on the mode control signal to place the pixel in an LCG mode; then performing a second charge transfer from the photodiode to the read node at the LCG; a third transition is then performed on the mode control signal to place the pixel back to the HCG mode. During the low gain transition, a pulse of a mode control signal is generated, the pulse of the mode control signal framing a pulse that triggers charge transfer. This enables only three ramps to be used.