Methods and systems for a narrowband, non-linear optoelectronic receiver are disclosed and may include amplifying a received signal, limiting a bandwidth of the received signal, and restoring the signal utilizing a level restorer, which may include a non-return to zero (NRZ) level restorer. The NRZ level restorer may include a pulse-triggered bistable circuit, which may include two parallel inverters, with one being a feedback path for the other. The inverters may be single-ended or differential. A photogenerated signal may be amplified in the receiver utilizing a transimpedance amplifier and programmable gain amplifiers (PGAs). A received electrical signal may be amplified via PGAs. The bandwidth of the received signal may be limited utilizing one or more of: a low pass filter, a bandpass filter, a high pass filter, a differentiator, or a series capacitance on the chip. The signal may be received from a photodiode integrated on the chip.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

Per-port performance optimization may be provided. First, performance data may be received corresponding to each of a plurality of ports. Then it may be determined that performance of at least one of the plurality of ports can be improved based on the received performance data corresponding to the least one of the plurality of ports. Next, in response to determining that the performance of the at least one of the plurality of ports can be improved, at least one of a plurality of components may be adjusted corresponding to the at least one of the plurality of ports to improve performance of the least one of the plurality of ports.

The present disclosure relates to an optical repeater system for 5th generation (5G) mobile communication. The optical repeater system does not require an additional optical wavelength for a plurality of remote units and can increase the transmission capacity by adding a remote unit without incurring an unnecessary cost, thereby facilitating high-speed and large-capacity data transmission. In addition, the optical repeater system can transmit/receive both a high-speed and large-capacity service signal, as an analog optical signal, and a management control signal, as a digital optical signal, between a master unit and a plurality of remote units. Also, the optical repeater system can selectively and differently compensate for propagation delay times of multiple paths between a terminal and a base station in a mobile communication system, especially, in the 5G mobile communication system.

In an optical receiver, a control unit determines an SOA current set value such that an SOA current becomes a maximum value I.sub.SOA_MAXwhen a VOA voltage is smaller than a first threshold value V.sub.VOA_LOW, determines the SOA current set value such that the SOA current becomes smaller than the maximum value I.sub.SOA_MAX and larger than a minimum value I.sub.SOA_MIN when the VOA voltage is equal to or larger than the first threshold value V.sub.VOA_LOW and is smaller than a second threshold value V.sub.VOA_HIGH, and determines the SOA current set value such that the SOA current is fixed to the minimum value I.sub.SOA_MIN when the VOA voltage is equal to or larger than the second threshold value V.sub.VOA_HIGH.

In optical receivers, extending the transimpedance amplifier's (TIA) dynamic range is a key to increasing the receiver's dynamic range, and therefore increase the channel capacity. Ideally, the TIA requires controllable gain, whereby the receiver can modify the characteristics of the TIA and/or the VGA to process high power incoming signals with a defined maximum distortion, and low power incoming signals with a defined maximum noise. A solution to the problem is to provide TIA's with reconfigurable feedback resistors, which are adjustable based on the level of power, e.g. current, generated by the photodetector, and variable load resistors, which are adjustable based on the change in impedance caused by the change in the feedback resistor.

A transimpedance amplifier (TIA) structure includes an input node with a variable inductance component serving to reduce variation in peak amplitude over different gain conditions. According to certain embodiments, an inductor at the TIA input has a first node in communication with a Field Effect Transistor (FET) drain, and a second node in communication with the FET source. A control voltage applied to the FET gate effectively controls the input inductance by adding a variable impedance across the inductor. Under low gain conditions, lowering of inductance afforded by the control voltage applied to the FET reduces voltage peaking. TIAs in accordance with embodiments may be particularly suited to operate over a wide dynamic range to amplify incoming electrical signals received from a photodiode.

An optical receiver includes a transimpedance amplifier that converts a current signal corresponding to an optical signal into a voltage signal. The transimpedance amplifier includes an input terminal receiving the current signal, an output terminal outputting the voltage signal, an inverting circuit including a pull-up device that pull-up drives the voltage signal of the output terminal according to the current signal, and a pull-down device that pull-down drives the voltage signal of the output terminal according to the current signal, a feedback resistor electrically connected between the input and output terminals, a first resistor electrically connected between the input terminal and the pull-up device, and a second resistor electrically connected between the input terminal and the pull-down device.

The present disclosure relates to an optical repeater system for 5th generation (5G) mobile communication. The optical repeater system does not require an additional optical wavelength for a plurality of remote units and can increase the transmission capacity by adding a remote unit without incurring an unnecessary cost, thereby facilitating high-speed and large-capacity data transmission. In addition, the optical repeater system can transmit/receive both a high-speed and large-capacity service signal, as an analog optical signal, and a management control signal, as a digital optical signal, between a master unit and a plurality of remote units. Also, the optical repeater system can selectively and differently compensate for propagation delay times of multiple paths between a terminal and a base station in a mobile communication system, especially, in the 5G mobile communication system.

An amplifier typically exemplified by a TIA is realized that provides an optimal band characteristic, that reduces the possibility of the oscillation, and that achieves a reduced dispersion of the band characteristics. An amplifier for amplifying an electric signal, comprising: a first buffer for amplifying the electric signal; a filter that is connected to an output of the first buffer and that includes a parallel circuit consisting of an inductor and a first capacity; and a second buffer connected to an output of the filter.