Signal amplifier and optical signal receiver using the same

A signal amplifier comprising:

• a level detector for detecting a direct voltage level of either a normal phase signal or an inverse phase signal;
• a first adder for adding either said inverse phase signal or said normal phase signal to a detection output of said level detector;
• a second adder for adding said normal phase signal to said inverse phase signal;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said level detector includes:
• a peak detector for detecting the maximum value of either said inverse phase signal or said normal phase signal,
• a first bottom detector for detecting a relatively minimum value of either said inverse phase signal or said normal phase signal referenced from a detection level of said peak detector, and
• a voltage divider for dividing the voltages between detection outputs of said peak detector and said first bottom detector.

A signal amplifier comprising:

• a first level detector for detecting a direct voltage level of a normal phase signal;
• a first adder for adding an inverse phase signal to a detection output of said first level detector;
• a second level detector for detecting a direct voltage level of said inverse phase signal;
• a second adder for adding said normal phase signal to a detection output of said second level detector;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said first level detector includes:
• a first peak detector for detecting the maximum value of said normal phase signal;
• a first voltage divider for dividing the voltages between an output of said first peak detector and said normal phase signal;
• and
• a first bottom detector for obtaining a relatively minimum value of a voltage division signal from said first voltage divider being referenced from the output of said first peak detector;
• and
• wherein the second level detector includes:
• a second bottom detector for detecting the minimum value of said inverse phase signal;
• a second voltage divider for dividing the voltages between an output of said second bottom detector and said normal phase signal;
• and
• a second peak detector for obtaining a relatively maximum value of the voltage division signal from said second voltage divider being referenced from the output of said second peak detector.

A signal amplifier comprising:

• a level detector for detecting a direct voltage level of either a normal phase signal or an inverse phase signal;
• a first adder for adding either said inverse phase signal or said normal phase signal to a detection output of said level detector;
• a second adder for adding said normal phase signal to said inverse phase signal;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said level detector includes:
• a bottom detector for detecting the minimum value of said inverse phase signal;
• a voltage divider for dividing the voltages between an output of said bottom detector and said normal phase signal;
• and
• a peak detector for obtaining a relatively maximum value of the voltage division signal from said voltage divider being referenced from the output of said peak detector.

A signal amplifier comprising:

• a first level detector for detecting a direct voltage level of a normal phase signal;
• a first adder for adding an inverse phase signal to a detection output of said first level detector;
• a second level detector for detecting a direct voltage level of said inverse phase signal;
• a second adder for adding said normal phase signal to a detection output of said second level detector;
• and
• a different amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein each of said first level detector and said second level detector includes:
• a peak detector for detecting the maximum value of an input signal;
• a bottom detector for detecting the minimum value of said input signal;
• and
• a voltage divider for dividing the voltages between the outputs of said peak detector and said bottom detector.

A signal amplifier having a plurality of amplifiers configured with a multi-stage cascade connection, wherein an amplifier in at least one stage among said plurality of amplifier stages comprises:

• a first level detector for detecting a direct voltage level of a normal phase signal;
• a first adder for adding an inverse phase signal to a detection output of said first level detector;
• a second level detector for detecting a direct voltage level of said inverse phase signal;
• a second adder for adding said normal phase signal to a detection output of said second level detector;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said first level detector includes:
• a first peak detector for detecting the maximum value of said normal phase signal,
• a first bottom detector for detecting a relatively minimum value of said normal phase signal referenced from a detection level of said first peak detector, and
• a first voltage divider for dividing the voltages between detection outputs of said first peak detector and said first bottom detector;
• and
• wherein said second level detector includes:
• a second bottom detector for detecting the minimum value of said inverse phase signal,
• a second peak detector for detecting a relatively maximum value of said inverse phase signal referenced from a detection level of said second bottom detector, and
• a second voltage divider for dividing the voltages between detection outputs of said second bottom detector and said second peak detector.

A signal amplifier having a plurality of amplifiers configured with a multi-stage cascade connection, wherein an amplifier in at least one stage among said plurality of amplifier stages comprises:

• a level detector for detecting a direct voltage level of either a normal phase signal or an inverse phase signal;
• a first adder for adding either said inverse phase signal or said normal phase signal to a detection output of said level detector;
• a second adder for adding said normal phase signal to said inverse phase signal;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said level detector includes:
• a peak detector for detecting the maximum value of either of said inverse phase signal or said normal phase signal,
• a first bottom detector for detecting a relatively minimum value of either said inverse phase signal or said normal phase signal referenced from a detection level of said peak detector, and
• a voltage divider for dividing the voltages between detection outputs of said peak detector and said first bottom detector.

An optical signal receiver comprising:

• an optical signal detector;
• a pre-amplifier for converting a voltage signal having been converted by said optical signal detector to a corresponding voltage signal to amplify;
• and
• a signal amplifier to which a normal phase signal and an inverse phase signal being output from said pre-amplifier are input,
• wherein said signal amplifier includes:
• a first level detector for detecting a direct voltage level of a normal phase signal;
• a first adder for adding an inverse phase signal to a detection output of said first level detector;
• a second level detector for detecting a direct voltage level of said inverse phase signal;
• a second adder for adding said normal phase signal to a detection output of said second level detector;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said first level detector includes:
• a first peak detector for detecting the maximum value of said normal phase signal,
• a first bottom detector for detecting a relatively minimum value of said normal phase signal referenced from a detection level of said first peak detector, and
• a first voltage divider for dividing the voltages between detection outputs of said first peak detector and said first bottom detector;
• and
• wherein said second level detector includes:
• a second bottom detector for detecting the minimum value of said inverse phase signal,
• a second peak detector for detecting a relatively maximum value of said inverse phase signal referenced from a detection level of said second bottom detector, and
• a second voltage divider for dividing the voltage between detection outputs of said second bottom detector and said second peak detector.

An optical signal receiver comprising:

• a light receiving element;
• a pre-amplifier for converting a voltage signal having been converted by said light receiving element to a corresponding voltage signal to amplify;
• and
• a signal amplifier to which a normal phase signal and an inverse phase signal being output from said pre-amplifier are input,
• wherein said signal amplifier includes:
• a level detector for detecting a direct voltage level of either a normal phase signal or an inverse phase signal;
• a first adder for adding either said inverse phase signal or said normal phase signal to a detection output of said level detector;
• a second adder for adding said normal phase signal to said inverse phase signal;
• and
• a differential amplifier for differential-amplifying outputs of said first adder and said second adder,
• wherein said level detector includes:
• a peak detector for detecting the maximum value of either said inverse phase signal or said normal phase signal,
• a first bottom detector for detecting a relatively minimum value of either said inverse phase signal or said normal phase signal referenced from a detection level of said peak detector, and
• a voltage divider for dividing the voltages between detection outputs of said peak detector and said first bottom detector.