NRZ SIGNAL AMPLIFYING DEVICE AND METHOD, AND ERROR RATE MEASUREMENT DEVICE AND METHOD

摘要

To set an optimum offset voltage and detect an NRZ signal with a very small amplitude. An NRZ signal amplifying device 2 includes: input-side voltage detection means 13 for detecting a high-level voltage and a low-level voltage of an input signal to the main amplifier 12; output-side voltage detection means 14 for detecting the two signals inverted relative to each other; and offset voltage control means 15 for calculating a center voltage between the detected high-level voltage and low-level voltage, setting an offset voltage at which the center voltage is the center of an appropriate input range of the main amplifier 12 to the offset circuit 11, and finely adjusting the offset voltage, such that a voltage difference between the detected two signals inverted relative to each other and a polarity change point is close to 0.

主权项

1. An NRZ signal amplifying device comprising:
an offset circuit that applies an offset voltage to an NRZ signal which is input as a signal to be amplified and outputs the signal; a main amplifier that receives the output signal from the offset circuit, amplifies the output signal, and outputs the amplified signal as two signals which are inverted relative to each other; input-side voltage detection means for detecting a high-level voltage and a low-level voltage of an input signal to the main amplifier; output-side voltage detection means for detecting the voltages of the two signals inverted relative to each other which are output from the main amplifier; and offset voltage control means for calculating a center voltage between the high-level voltage and the low-level voltage detected by the input-side voltage detection means, calculating an offset voltage at which the calculated center voltage is the center of an appropriate input range of the main amplifier, setting the offset voltage to the offset circuit, and finely adjusting the offset voltage, such that a voltage difference between the two signals inverted relative to each other which are output from the main amplifier and are detected by the output-side voltage detection means is close to 0.