Fiber-to-the-home (FTTH) optical receiver with distributed gain control

In a fiber-to-the-home (FTTH) system for transmitting forward and reverse optical signals via optical fiber, the FTTH system including a plurality of home network units, the plurality of home network units including an optical receiver for receiving at least one of video, voice, and data signals, and for providing the at least one of the video, voice, and data signals to a connected device via coaxial cable, the optical receiver comprising:

• a photodiode for converting an optical signal into an RF signal;
• a plurality of gain stages for amplifying the RF signal throughout the optical receiver,
• wherein the plurality of gain stages comprises a preamplifier and a postamplifier stage and a first and second interstage amplifier coupled between the preamplifier and postamplifier stages,
• whereby positioning the plurality of gain stages throughout the optical receiver provides a postamplifier output signal having a desired level with a low output noise signal;
• a first gain control network for receiving the RF signal from the photodiode, wherein the RF signal comprises an input power level of the at least one optical signal, and for providing an optical control signal;
• a first attenuator coupled between the preamplifier stage and the first interstage amplifier, the first attenuator for receiving the optical control signal and attenuating the RF signal when the input power level of the optical signal is beyond a predetermined range;
• a second attenuator coupled between the first and second interstage amplifiers;
• and
• a second gain control network coupled to an output of the postamplifier stage, the second gain control network for providing an RF control signal that is indicative of a level associated with the postamplifier output signal.

A method of providing an amplified RF output signal, the method performing the steps of:

• receiving an input optical signal at an optical receiver;
• converting the input optical signal into an RF signal;
• amplifying the RF signal with a plurality of gain stages located throughout the optical receiver to provide an RF output signal having a desired level,
• wherein the plurality of gain stages comprise a preamplifier stage, a first interstage amplifier, a second interstage amplifier, and a postamplifier stage;
• attenuating the RF signal with a first attenuator at an output of the preamplifier stage when an input level of the RF signal is beyond a predetermined threshold;
• and
• attenuating the RF signal with a second attenuator positioned between the first and second interstage amplifiers;
• providing the second attenuator an RF control signal that is indicative of a level associated with the RF output signal, wherein the second attenuator attenuates the RF signal based on the RF control signal to maintain the output RF signal at the desired level.

A communications system comprising an optical receiver, the optical receiver for receiving an optical input signal and providing an RF output signal, the optical receiver comprising:

• a photodiode for converting an optical signal having an optical level into an RF signal having an RF level, where the RF level is equivalent to the optical level;
• a preamplifier stage coupled to the photodiode for receiving the RF signal and for providing an amplified signal;
• a first attenuator coupled to the preamplifier stage for attenuating the RF level in accordance with an optical control signal;
• a first and second interstage amplifier coupled to the first attenuator for amplifying the RF signal;
• a second attenuator coupled to the second interstage amplifier for further attenuating the RF level in accordance with an RF control signal;
• a postamplifier stage coupled to the second attenuator for final amplification of the RF signal,
• wherein the RF level of the RF signal provided by the postamplifier stage is at the predetermined level;
• a first gain control network for receiving the RF signal from the photodiode and for providing the optical control signal indicative of the level of the RF signal from the photodiode;
• and
• a second gain control network for receiving the RF signal from the postamplifier stage and providing the RF control signal to the second attenuator indicative of the level of the RF output signal.