515 results about "Trans impedance amplifier" patented technology

A measurement system is provided that includes a probe device having an integrated amplifier. The integrated amplifier may be a transimpedence amplifier that amplifies input current to an output voltage.

The apparatus includes a case having a base member, two partial side members, and a lid member to provide a spatial volume with an opening at a back end of the base member. Additionally, the apparatus includes a PCB installed inside the spatial volume over the base member with a pluggable connector at the back end. The apparatus includes one or more optical transmitting devices in transmit-optical-sub-assembly package, each being mounted upside-down on the PCB and including a built-in TEC module in contact with the lid member and a laser output port aiming toward the back end. Furthermore, the apparatus includes a silicon photonics chip including a fiber-to-silicon attachment module, mounted on the PCB and coupled to a modulation driver module and a trans-impedance-amplifier module. Moreover, the apparatus includes an optical input port and output port being back connected to the fiber-to-silicon attachment module.

Disclosed herein is a monolithically integrated coherent receiver chip which has a geometric arrangement of the on-chip components that significantly improves the performance and the manufacturability of a coherent receiver module for Dual Polarization Quadrature Phase Shift Keyed (DP-QPSK) applications and other optical coherent detection systems. The coherent receiver chip comprises two optical hybrids, three optical inputs and eight electrical outputs with the two optical hybrids oriented perpendicular to the optical inputs and the electrical outputs which are widely spaced and arranged in a co-linear fashion that simplifies module design and assembly. The proposed geometric arrangement also replaces any optical waveguide crossings with vertical electrical-optical crossings and includes electrical transmissions which are used to minimize channel skew. The proposed configuration also has the additional benefit of improved thermal management by separating the module's trans-impedance amplifiers.

The invention provides an optical-receiver preamplifier for receiving analog or digital optical signals. The preamplifier comprises a high-gain amplifier A1, an input circuit, a negative-feedback impedor Zf, a low-gain amplifier A2 adjustable in gain and a feedback capacitor Cff, wherein the input circuit takes a photoelectric converter as a main component; the negative-feedback impedor Zf is connected with the reverse input end and the output end of the A1; the feedback capacitor Cff connects the output end of the A2 with the reverse input end of the A1; and the output end of the A1 can be directly connected with the input end of the A2 or can be connected with the input end of the A2 through a buffer. Output signals of the preamplifier are taken out from the output end of the A1 or the output end of the buffer, and can be directly subjected to subsequent signal processing or be further amplified and then subjected to subsequent signal processing.

The disclosed systems and methods utilize an advanced linearized trans-impedance amplifier (ATIA) that allows for the recovery and amplification of low amplitude analog and digital signals. This disclosure further describes unique approaches of addressing issues inherent in the transmission and reception of small amplitude multi-carrier signals used for distribution of voice, video, and data communications over both fiber optic cables and free space transmitters

The invention relates to a DC offset cancellation circuit for a trans-impedance amplifier, which is typically used for converting an input current from a photodiode into an output voltage. The DC offset cancellation circuit utilizes the monitor current from a photodiode monitoring device to cancel the DC offset from the photodiode input current, enabling the conventional feedback circuit in the trans-impedance amplifier to be fully integrated.

The invention provides a 400 Gbps hot-plug high-speed optical transceiver module which is suitable for the optical communication technical field. The 400 Gbps hot-plug high-speed optical transceiver module comprises an optical interface unit, a photoelectric transceiver unit and an electrical interface unit; the photoelectric transceiver unit is used for achieving the functions of photoelectric conversion and high-speed electrical signal processing through a photoelectric transceiver chip; the internal working process of the photoelectric transceiver chip comprises receiving an electrical signal input through the electrical interface unit by a transmitting terminal data clock recovery circuit, loading the electrical signal to a laser after the pretreatment through a driving circuit, converting the high-speed electrical signal into a high-speed optical signal through the laser, reusing the high-speed optical signal through a wavelength division multiplexer to be output, reusing the received optical signal into a 16-channel optical signal through a wavelength division demultiplexer to be transmitted to an optical detector and transmitting the 16-channel optical signal to a trans-impedance amplifier and a receiving terminal data clock recovery circuit after photoelectric conversion to be processed. According to the 400 Gbps hot-plug high-speed optical transceiver module, the factors such as the cost, the transmission loss, the chromatic dispersion and the size are considered to select different optical transceiver modules and accordingly the long-distance single-mode optical fiber transmission or the short-distance multimode transmission is implemented.

The invention provides a high-gain and low-noise differential trans-impedance amplifier. The high-gain and low-noise differential trans-impedance amplifier comprises a current mirror, an adjusting type common-emitter and common-base trans-impedance amplifier and an output common-source amplifier, wherein the adjusting type common-emitter and common-base tarns-impedance amplifier comprises a common-base amplifying unit and a negative feedback common-emitter amplifying unit; the negative feedback common-emitter amplifying unit is arranged between an emitter and a base of the common-base amplifying unit and serves as a negative feedback channel; input current is copied by the current mirror in an equal proportion manner; the current mirror provides bias voltage for the common-base amplifying unit and the negative feedback common-emitter amplifying unit; the output common-source amplifier is connected between an output end of the adjusting type common-emitter and common-base trans-impedance amplifier and an output end of the high-gain and low-noise differential trans-impedance amplifier; and trans-impedance gain is increased. By the high-gain and low-noise differential tarns-impedance amplifier, received weak signals are amplified in a high-gain and low-noise manner, bandwidth is large, and a dynamic range of inputted current signals are reasonably set; and the high-gain and low-noise differential tarns-impedance amplifier has the advantages of easiness in design and monolithic integration.

The invention discloses a terahertz quantum well photodetector (THzQWP)-based passive thermal imaging detection system and a method thereof. A photoconduction THzQWP is taken as a photodetector, a self-designed radiation signal denoising modulation method, a synchronous control module and a signal transmission-convergence light path are adopted, and THzQWP-based passive thermal imaging detection is finished; a thermal radiation signal is modulated by an adjustable aperture diaphragm and a wave chopper at an acquisition end of the thermal radiation signal, and the modulation frequency is set by the wave chopper; a photoconduction mode is adopted at a signal detection circuit end of the THzQWP, the THzQWP receives the radiation signal through an off-axis parabolic mirror group convergence light path and extracts a THz signal, stable bias voltage is applied, THzQWP photocurrent is converted into voltage by a transimpedance amplifier, the voltage is amplified by a low noise amplifier, anddata is read by a phase-locked amplifier; and the read signal is recorded and processed by the synchronous control module, and thermal image information is acquired finally.

The present invention provides a method for calculating APD breakdown voltage and a circuit thereof. The method comprises the following steps: 1, adding reserve voltage Vapd on an APD in a condition without light; 2, dark current (Idark) generated by the APD flows into a trans-resistance amplifier (3) after passing through a current mirror (2); 3, reversely calculating the dark current (Idark) through output voltage (Vo) of the trans-resistance amplifier (3); and 4, determining whether the dark current (Idark) of the APD is equal to 10 [Mu]A or not, if the dark current (Idark) of the APD is equal to 10 [Mu]A, allowing the APD at present to be the breakdown voltage of the APD, or else, repeatedly setting the Vapd, and returning back to the step 3. The method for calculating APD breakdown voltage and the circuit thereof can accurately find the Vbr of the APD so as to find reasonable reverse direction work voltage Vapd, are good in precision, efficiency and consistence, improve the yield rate of an optical module, improve production efficiency and reduce production cost.

The invention discloses a transresistance amplifier with a received signal strength indication (RSSI) function. The transresistance amplifier is characterized in that an image current source and a second current voltage switching circuit are additionally arranged in an existing transresistance amplifier, so that an image current signal is generated and then converted into an image voltage signal used as an RSSI signal for output, thus the power loss brought by a differential amplifier device is eliminated; simultaneously the transresistance value of the second current voltage switching circuit ranges from 200ohm to 600ohm, thus the condition that the accuracy requirement of optical power detection cannot be met due to RSSI signal saturation caused by overlarge optical power can be prevented; and a BJT (bipolar junction transistor) image current source of a high-speed bandwidth small-signal triode is also used, so that the industrial cost is low while the speed requirement of signal high-speed transmission can be met; and finally the transresistance of a first current voltage switching circuit with a resistance value ranging from 800ohm to 2000ohm ensures that the signal-to-noise ratio of the differential amplifier is higher.

The invention discloses a high-speed CMOS monolithic integration light receiver front end of a cross coupling structure. The high-speed CMOS monolithic integration light receiver front end comprises a photoelectric detector of a completely-symmetric structure, a trans-impedance amplifier of a difference structure, a direct current excursion eliminating unit, a three-stage sequence cascaded difference limiting amplifier and an output buffer stage; the trans-impedance amplifier of the difference structure is used for converting current signals output by the photoelectric detector into voltage signals and conducting preliminary amplification; the direct current excursion eliminating unit is used for eliminating direct current excursion led in by non-balanced signals at the input end of the trans-impedance amplifier and enables common mode levels at the output end of the trans-impedance amplifier to be coincident; the three-stage sequence cascaded difference limiting amplifier is used for amplifying the voltage signals output by the trans-impedance amplifier to be at the voltage level needed by a digital processing unit. Through the adoption of the cross coupling structure, the noise in-phase counteraction technology and the parallel type active inductor design, a high-speed and high-sensitivity standard CMOS monolithic integration light receiver can be achieved.

The present invention provides an optical receiver operable for optical signals each having different transmission speed. The optical receiver includes a light-receiving device, a pre-amplifier, a main amplifier, and a control circuit. The pre-amplifier, may be a trans-impedance amplifier, includes a parallel connection of a switching device and a resistor in a trans-impedance or a load element. By switching ON/OFF the switching device, the gain and the bandwidth of the pre-amplifier may be changed. By providing a filter circuit, whose cut-off frequency may be switched, in the main amplifier, the bandwidth of the optical receiver may be varied.

A device and method to immune an APD or SiPM optical receiver against photodetector voltage supply variation is presented. A differential trans-impedance amplifier includes one input connected to the photodetector and the other input connected to a high voltage supply variation sensing device. The sensing element includes a circuit replicating the impedance of the photodetector.

The invention discloses an LED display screen indoor wireless communication system based on LiFi technology The LED display screen indoor wireless communication system comprises indoor LED lamps and LED display screens disposed in the illumination range of the LED lamps. A LiFi optical signal transmitting module is disposed in each of the LED lamps, and a main control circuit, a communication signal detection circuit, a circuit for transceiving wireless signals in various wavebands, and a LiFi optical signal receiving circuit are disposed in each of the LED display screen. Each of the main control circuits is connected with the corresponding communication signal detection circuit, the corresponding circuit for transceiving the wireless signals in various wavebands, and the corresponding LiFi optical signal receiving circuit. Each of the LiFi optical signal transmitting modules is connected with a LiFi wireless communication Internet signal source. Each of the LiFi optical signal transmitting modules of the LED lamps comprises a photoelectric communication device, which comprises an LED driver, an LED lamp bead, a PIN photoelectric diode, and a trans-impedance amplifier. A LiFi base station comprises an optical link, and is used to establish connection between an access end and an Internet end, and can be used for processing the electric signals, receiving and/or transmitting the electric signals.