| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 398210000 | Amplitude | 17 |
| 20080310861 | PON Burst Mode Receiver with Fast Decision Threshold Setting - A receiver converts an analog signal, derived from light pulses in a GPON fiber optic system, to clean digital electrical signals. A photodetector and transimpedance amplifier (TIA) convert the light pulses to analog electrical signals. A reset signal generated by a media access controller (MAC) in the GPON system signifies the start of a new burst of data. The receiver has a switchable low pass filter that establishes the threshold voltage for determining whether the analog signal is a logical 1 or a logical 0. At the very start of a new burst, the low pass filter has a fast time constant to quickly establish the threshold voltage for the burst. At a later time during the burst, the low pass filter is switched to have a slow time constant to create a relatively stable threshold voltage. | 12-18-2008 |
| 20090003845 | Automatic Threshold Voltage Adjustment Circuit for Dense Wavelength Division Multiplexing or Packet Transport System and Method of Operating the Same - An automatic threshold voltage adjustment circuit, a method of automatically adjusting threshold voltage and an optical receiver for an optical communication system. In one embodiment, the circuit includes: (1) an amplitude detector configured to detect an amplitude of a received optical signal, (2) a variable resistor coupled to the amplitude detector and including a field-effect transistor configured to operate in a triad mode to provide a resistance that varies substantially linearly based on the amplitude and (3) an operational amplifier coupled to the variable resistor and configured to apply a variable gain based on the resistance to an input threshold voltage to yield an adapted threshold voltage. | 01-01-2009 |
| 20090175631 | Pulse signal demodulation device - In an optical transmission system in which a pulse signal is converted into an optical signal before transmission, a pulse signal demodulation device capable of correctly demodulating the pulse signal is provided. An optical-to-electrical conversion section ( | 07-09-2009 |
| 20100119242 | INFRARED COMMUNICATIONS RECEIVER - An objective of one embodiment of the present invention is to reduce abrupt noise derived from infrared light emitted by a light source from a data signal of infrared light received by an infrared communications receiver for use with a display device including a light source without reducing the strength of the data signal. A multiplication factor for the amplitude of abrupt noise outputted by a lamp light-receiving element disposed in the vicinity of lamps of a liquid crystal television is adjusted in order for the amplitude of abrupt noise derived from the lamps and outputted by the lamp light-receiving element to be equalized with the amplitude of abrupt noise derived from the lamps and included in a data signal outputted by a data light-receiving element. Then, the abrupt noise subjected to multiplication factor adjustment is subtracted from the data signal including the abrupt noise, so that only the data signal remains and is transmitted to the liquid crystal television. | 05-13-2010 |
| 20100135678 | OPTICAL RECEIVING DEVICE, OPTICAL RECEIVING CIRCUIT, AND METHOD FOR RECEIVING OPTICAL SIGNALS - There is provided an optical receiving device for deriving a signal using for data identification. The optical receiving device includes a demodulator for demodulating a modulated optical signal to an demodulated optical signal, a convertor for converting the demodulated optical signal to a first and a second electric signals, a generator for generating a complement signal by summing the first electric signal of a normal in phase component and the second electric signal of a reverse in phase component, and a suppressor for suppressing, by the use of the complement signal, a variation of potential which appears in a data signal at a time of phase changing of the modulated optical signal, the data signal being a difference of the normal in phase component and the reverse in phase component. | 06-03-2010 |
| 20100278542 | BURST MODE OPTICAL RECEIVER - A system and computer readable medium for a burst mode optical receiver that enables an optical receiver to receive signals from a plurality of optical network units at different optical power levels. In an exemplary embodiment, the system may include a memory that stores a received signal strength indication, and a media access controller communicably coupled to the memory. The media access controller receives a received signal strength indication of an upcoming data stream to an optical network unit, and asserts a signal control voltage during a guard time to an optical receiver to optimize reception of incoming data streams of the optical network unit based upon the received signal strength indication received from the upcoming data stream. | 11-04-2010 |
| 20100303474 | DIGITAL COHERENT OPTICAL RECEIVER - A digital coherent optical receiver provided with a 90-degree optical hybrid circuit for detecting an in-phase signal and a quadrature signal of an input optical signal, includes first through fourth circuits. The first circuit calculates a square of a sum of the in-phase signal and the quadrature signal. The second circuit subtracts a squared value of the in-phase signal and a squared value of the quadrature signal from the calculation result of the first circuit. The third circuit detects a phase error of the 90-degree optical hybrid circuit based on the calculation result of the second circuit. The fourth circuit corrects at least one of the in-phase signal and the quadrature signal according to the phase error detected by the third circuit. | 12-02-2010 |
| 20120076508 | JITTER REDUCTION OF ELECTRICAL SIGNALS FROM LIMITING OPTICAL MODULES - Jitter reduction of electrical signals from limiting optical modules is described. In one example, a process includes receiving an amplitude limited electrical signal that has been converted from an optical signal, applying a filter to the received electrical signal, measuring an indication of jitter of the filtered signal, and selecting parameters of the linear filter based on the measured indication. | 03-29-2012 |
| 20120141145 | DQPSK OPTICAL RECEIVER - According to an aspect of an embodiment, a DQPSK optical receiver, comprising: a first LPF connected to a line branching off from between a first optical-electrical converter and a first data recovery circuit; a second LPF connected to a line branching off from between a second optical-electrical converter and a second data recovery circuit; a first LIA for amplifying a signal output from the first LPF and also limiting an amplitude of an output signal thereof; a second LIA for amplifying a signal output from the second LPF and also limiting an amplitude of an output signal thereof; a first mixer for multiplying the output signal from the first LIA by a signal output from the second LPF; and a second mixer for multiplying the output signal from the second LIA by a signal output from the first LPF. | 06-07-2012 |
| 20120148266 | DIGITAL COHERENT OPTICAL RECEIVER, ADAPTIVE EQUALIZER, AND DIGITAL COHERENT OPTICAL COMMUNICATION METHOD - A digital coherent optical receiver includes a processor that is operative to separate electric signals obtained by converting an optical signal into a horizontal signal component and a vertical signal component; to generate a histogram of the horizontal signal component and the vertical signal component as outputs of the equalizing filter; and to determine a presence/absence of local convergence based on distribution of the histogram of the horizontal signal component and the histogram of the vertical signal component. | 06-14-2012 |
| 20130108280 | Data Signal Threshold Detection and/or Recovery in Optical and/or Optoelectronic Receivers and/or Transceivers | 05-02-2013 |
| 20130202316 | OPTOELECTRONIC DEVICE FOR DIFFERENTIAL PHOTORECEPTION, WITH AUTOMATIC COMPENSATION OF PHASE AND AMPLITUDE IMBALANCES - An optoelectronic device includes a photodetection means arranged for converting first and second complementary optical signals into first and second complementary currents, and a processing means arranged for processing these first and second complementary currents to output at least a first output voltage. This processing means includes i) a conversion means arranged for separately converting the first and second complementary currents into first and second operating voltages, ii) a balancing means arranged for balancing phase and amplitude of the first and second operating voltages, and iii) a differential amplification means arranged for applying a subtraction function to the first and second operating voltages with balanced phase and amplitude to produce at least the first output voltage, which is proportional to the difference between the first and second operating voltages with balanced phase and amplitude. | 08-08-2013 |
| 20140119746 | INTEGRATED CIRCUITS IN OPTICAL RECEIVERS - A circuit may include a photodiode configured to receive an optical signal and convert the optical signal to a current signal. The circuit may also include a transimpedance amplifier coupled to the photodiode and configured to convert the current signal to a voltage signal. The circuit may also include an equalizer coupled to the transimpedance amplifier and configured to equalize the voltage signal to at least partially compensate for a loss of a high frequency component of the optical signal. The equalizer and the transimpedance amplifier may be housed within a single integrated circuit. | 05-01-2014 |
| 20140193164 | OPTICAL RECEIVING CIRCUIT - An optical receiving circuit includes: a first non-feedback amplifier configured to convert a current signal, obtained from a light receiving element in response to an optical signal, into a first voltage signal; a second amplifier configured to convert an input current signal into a second voltage signal, the output signal not being directly fed back to an input side; a differential amplifier configured to perform differential amplification on the first voltage signal and the second voltage signal and to output an in positive signal and a negative signal obtained through the differential amplification; and an offset compensation circuit configured to input, on the basis of the in positive signal and the negative signal output from the differential amplifier, an offset current signal in accordance with an offset of a level of the in positive signal from a level of the negative signal to the second amplifier. | 07-10-2014 |
| 20140334831 | OPTICAL RECEIVER AND LIGHT RECEIVING METHOD - An optical receiver receives coherent light. The optical receiver includes an amplitude adjuster, a signal processor, and a controller. The amplitude adjuster adjusts amplitude of an input signal to output an analog signal. The signal processor receives a digital signal generated from the analog signal output from the amplitude adjuster, extracts clock components from the digital signal, and after establishing synchronization between the clock components and data components, extracts the data components from the digital signal to process the data components. The controller sets amplitude of the analog signal to first amplitude before establishment of synchronization by the digital signal, and changes the set amplitude to second amplitude that is smaller than the first amplitude after the establishment of synchronization. | 11-13-2014 |
| 20140356003 | OPTICAL RECEIVER HAVING A CHROMATIC-DISPERSION COMPENSATION MODULE WITH A MULTIBRANCH FILTER-BANK STRUCTURE - An optical receiver having an electronic dispersion-compensation module with two parallel signal-processing branches configured to provide a greater range of dispersion compensation than that provided by a prior-art device of comparable implementation complexity. In an example embodiment, each of the signal-processing branches includes a respective bank of finite-impulse-response filters that are configured in accordance with a different respective approximation of the group delay that needs to be compensated. The two group-delay approximations used by the filter banks rely on different respective step functions, each having a respective plurality of quantized steps, with the transitions between adjacent steps in one step function being spectrally aligned with the flat portions of the corresponding steps in the other step function. The filter banks may be further configured to apply different respective frequency-dependent phase-shift and/or amplitude-scaling profiles designed to reduce signal distortions associated with the transitions between adjacent steps in the step functions. | 12-04-2014 |
| 20160013869 | OPTICAL RECEIVER MODULE PROVIDING SEMICONDUCTOR OPTICAL AMPLIFIER | 01-14-2016 |
