114results about How to "Improve conversion gain" patented technology

A pixel cell with increased dynamic range is formed by providing a floating diffusion region having a variable capacitance, controlled by at least one gate having source and drain regions commonly connected to the floating diffusion region. The gate has an intrinsic capacitance which, when the gate is activated, is added to the capacitance of the floating diffusion region, providing a low conversion gain readout. When the gate is off, the floating diffusion region capacitance is minimized, providing a high conversion gain readout. The gate may also be selectively switched to mid-level. At mid-level, a mid-level conversion gain, which is between the high and low conversion gains, readout is provided, but the gate still provides some capacitance to prevent the floating diffusion region from saturating.

A pixel structure comprises a photo-sensitive element for generating charge in response to incident light. A first transfer gate is connected between the photo-sensitive element and a first charge conversion element. A second transfer gate is connected between the photo-sensitive element and a second charge conversion element. An output stage outputs a first value related to charge at the first charge conversion element and outputs a second value related to charge at the second charge conversion element. A controller controls operation of the pixel structures and causes a pixel structure. The controller causes the pixel structure to: acquire charges on the photo-sensitive element during an exposure period; transfer a first portion of the charges acquired during the exposure period from the photo-sensitive element to the first charge conversion element via the first transfer gate; and transfer a second portion of the charges acquired during the exposure period from the photo-sensitive element to the second charge conversion element via the second transfer gate.

The invention discloses a configurable multi-mode multi-band satellite navigation receiving method and a radio frequency front end module constructed by the method. The front end module can receive signals of satellite navigation and positioning systems such as a global positioning system (GPS), the Big Dipper, a Galileo positioning system and a global navigation satellite system (Glonass), and comprises a configurable low-noise amplifier (LNA) with a buffer and an active balun, a folding passive mixer with a configurable frequency synthesizer, a configurable multi-mode filter, an automatic gain control (AGC) amplifier, a direct-current bias circuit, and a multi-mode multi-band program controlled and coded on-off control word from a receiving system. The radio frequency front end module can meet the requirement of multi-band multi-mode work through the control word programmed by the receiving system, has a simple and reliable structure, does not need complicated time division multiplexing control system and off-chip module, has low cost and high flexibility, and improves the noise performance of the radio frequency front end of the whole receiver and multi-mode multi-band signal processing capacity; and a one-channel signal is input into the module, and the module outputs a two-channel differential signal. The receiver can be used for receiving and processing multi-mode satellite navigation signals asynchronously, and receiving and processing satellite navigation signals with the required mode in different time intervals according to the requirement.

A buffer layer made of i-GaAs not doped with impurities, and an n⁺ GaAs layer doped with a high-concentration of n-type impurities are stacked in the order named on a semi-insulating GaAs substrate. An n⁻ GaAs layer doped with a low-concentration of n-type impurities is partially located on the n⁺ GaAs layer. Cathode electrodes are located in opening regions in which the n⁻ GaAs layer is not present on the n⁺ GaAs layer. An anode electrode is located on the n⁻ GaAs layer. The n⁺ GaAs layer has a carrier concentration of 5×10¹⁸ cm⁻³, and is in ohmic contact with the cathode electrodes. The n⁻ GaAs layer has a carrier concentration of 1.2×10¹⁷ cm⁻³, and is in Schottky contact with the anode electrode.

A single-exposure high dynamic range (HDR) image sensor includes a first photodiode and a second photodiode, with a smaller full-well capacity than the first photodiode, disposed in a semiconductor material. The image sensor also includes a first floating diffusion disposed in the semiconductor material and a first transfer gate coupled to the first photodiode to transfer first image charge accumulated in the first photodiode into the first floating diffusion. A second floating diffusion is disposed in the semiconductor material and a second transfer gate is coupled to the second photodiode to transfer second image charge accumulated in the second photodiode into the second floating diffusion. An attenuation layer is disposed between the second photodiode and image light directed towards the single-exposure HDR image sensor to block a portion of the image light from reaching the second photodiode.

An integrated semiconductor image-rejection mixer having high linearity and high gain. In addition to the components of a classic image-rejection architecture, the present mixer has a high-frequency current-diverting stage that permits the operation of the output stage with high conversion gain and sufficient headroom for good linearity, even in cases where the supply voltage is relatively low (such as 3 V). The conversion gain of the mixer and its image-rejection performance can be changed by changing the load resistances and the elements of the output polyphase network, with minor effects on linearity and no change in power consumption or DC levels. The power consumption of the image-rejection mixer is low because no additional DC current is required for buffers or amplifier stages.

The invention provides a novel terahertz band broadband monolithic integrated subharmonic mixer comprising radio frequency and a local oscillation signal loading coupler, a diode pair composed of two diodes reversely connected in parallel, an intermediate frequency output amplifier circuit and a low pass filter, wherein a radio frequency signal is filtered by a first coplanar waveguide through a radio frequency band stop filter with a 1/2 radio frequency signal wavelength and is imported by a second coplanar waveguide onto an intermediate pin of the diode pair; and a local oscillation signal is filtered by a third coplanar waveguide through a local oscillation band-pass filter with a 1/4 local oscillation signal wavelength and is imported by the second coplanar waveguide onto the intermediate pin of the diode pair to be mixed with the radio frequency signal. By adoption of the scheme, the ultra wide working frequency range of the terahertz monolithic integrated subharmonic mixer is realized, and the scheme has the performance indexes of low frequency conversion loss, low manufacturing cost and high port isolation, and the like.

The invention belongs to the technical field of wireless communication, and relates to a mixer, in particular to a high-isolation broadband millimeter wave mixer applied to 5G communication, which comprises a transconductance stage unit 1, an electromagnetic coupling unit 2, a switch stage unit 3, a load stage unit 4 and a buffer stage unit 5. According to the electromagnetic coupling type common-gate structure mixer based on the CMOS technology, the common-gate input transconductance stage is adopted, system-level design is facilitated, and broadband matching can be achieved without an extramatching network; the transformer network and the standard inductor LP introduced in the middle can counteract the interstage parasitic capacitance, so that the noise is reduced, the gain is improved,the differential inductor LS can be matched with and form feedback requirements, and the gain is further improved; and meanwhile, the circuit structure is symmetrical, so that the circuit structure can be well symmetrical when an actual layout is implemented, thereby being beneficial to the isolation of the mixer.

The invention discloses a current reuse high linearity folding current mirror mixer. A double balanced frequency mixing switch pair is embedded into a current mirror, under common effect of the current mirror and the double balanced switch pair, radio frequency current of a transconductance grade generates an intermediate frequency current signal after frequency conversion, amplitude is consistent with the radio frequency current of the transconductance level, and output voltage is formed on a load resistor. According to the structure based on the current mirror, linearity deterioration of a traditional foldable Gilbert mixer caused by cascade is avoided, simultaneously, input and output static bias current of the current mirror are reused, and an inductance capacitor parallel network is used to realize isolation of a radiofrequency signal. According to the series connected gate tube, on one hand, isolation of an output terminal intermediate frequency signal from a radio frequency transconductance grade output terminal is realized, on the other hand, voltage fluctuation of a current mirror output terminal is stabilized, and accuracy of current mirror duplication is raised. The input and output static bias current of the current mirror is injected to the transconductance grade, current utilization efficiency is raised, and power consumption is reduced.

The invention discloses an ultralow consumption current multiplexing mixer based on substrate bias. The mixer comprises the following parts: a transconductance grade consisting of a pair of NMOS (N-channel Metal Oxide Semiconductor) pipes and a pair of PMOS (P-channel Metal Oxide Semiconductor) pipes, a switch grade consisting of two pairs of NMOS pipes, and a load grade consisting of resistors. The transconductance grade of the mixer utilizes a self-bias complementary transconductance structure and forms a folding structure with the switch grade to greatly reduce voltage of a power supply; substrates of all the MOS pipes in a circuit are additionally provided with fixed bias voltage to reduce threshold voltage of the MOS pipe and realize the design of ultralow voltage ultralow power consumption; and through a current multiplexing technique, the noise performance of the circuit is modified, and the conversion gain and the linearity are improved. The ultralow consumption current multiplexing mixer based on the substrate bias, disclosed by the invention, can be applied to deep submicron radio frequency CMOS (Complementary Metal Oxide Semiconductor) integrated circuits and can be widely applied to electronic systems in the aerospace field.

The invention discloses a current multiplying self-biasing current multiplexing passive frequency mixer which comprises a self-biasing input transconductance stage, a passive local oscillator switch and a low voltage transimpedance amplifier. The self-biasing input transconductance stage is provided with a self-biasing transconductance stage combined with a capacitive coupling current mirror. On one hand, transconductance current and the transimpedance amplifier are multiplexed. On the other hand, the bias current of the transimpedance amplifier can be precisely fixed. An additional differential pair is introduced in the low voltage transimpedance amplifier. The source of a common-gate tube is equivalent to virtual ground under a transconductance enhancement circuit. A transconductance tube in the differential pair replicates the current of the common-gate tube, and the current is injected into a load. Down-converted current is multiplied. Compared with a conventional passive frequency mixer, the current multiplying self-biasing current multiplexing passive frequency mixer provided by the invention has the advantages that the power supply voltage and bias current are reduced simultaneously; higher efficiency is realized; the conversion gain is improved; and the noise performance is improved.

The invention discloses a CMOS (complementary metal oxide semiconductor) image sensor column-sharing 2X2 pixel unit and a CMOS image sensor pixel array. Four pixels are arrayed to a 2X2 pixel array to serve as a pixel unit group, and two pixels in the front column and two pixels in the rear column of each pixel unit group respectively share a selective transistor, a source following transistor, a reset transistor and a drift active region in the same column. Metal wiring in a two-dimensional pixel array of a CMOS image sensor is achieved by metal wires in two layers, the metal wires in the zero layer and the metal wires in the first layer are used as device control wires to achieve an image information acquisition function, the metal wires in the second layer or the higher layer are unused as device control wires, and the dielectric height on the Si surface of a photodiode can be decreased to enable more light to be incident to the photodiode, so that light use efficiency and conversion gain of a small-area pixel sensor can be increased, and further, sensitivity is improved, and image quality of the small-area pixel image sensor can be effectively improved.

The invention discloses a data processing method for a THz-grade large-bandwidth laser synthetic aperture radar imaging system, which is composed of a linear tuning semiconductor, a 99:1 optical fiber coupler, a 90:10 optical fiber coupler, an emission collimating lens, a polarized beam splitter, a lambda/4 wave plate, a target displacement platform, a receiving collimating mirror, four 50:50 optical fiber couplers, two balancing detectors, a reference time delay optical fiber, a molecular wavelength reference device, an optical power meter, a data acquisition module and a data processing program module. The laser synthetic aperture radar imaging system disclosed by the invention is based on a large-range linear tuning laser pulse signal; and a target two-dimensional image is calculated according to the homodyne coherent detection technology, the balance detection technology, the synthetic aperture technology and the final special data processing procedure. The system has the advantages of short laser signal wavelength, large bandwidth, high imaging resolution, all-weather characteristic, high stability, simple structure, high detection sensitivity and long acting distance, and most of the system is based on the optical fiber device.