| 摘要 |
PURPOSE: An apparatus and method for removing a nonlinear distortion in an optical transmitter is provided to generate a signal in which a level is same and a phase is opposite with a nonlinear distortion signal and transmit only a main signal in which the nonlinear distortion signal is removed by using a pre-distortion type together with a feed-forward type. CONSTITUTION: An input matching unit(215) adjusts an input resistance of a transmitting main signal. A variable signal generating unit(210) generates a signal having a level and a phase corresponding to a uniform rate of the main signal which branches by the first coupling unit(205). An emitting unit(225) converts the main signal into an optical signal and emits an optical energy. An optical detecting unit(230) optically connects to the emitting unit(225) and couples the optical signal emitted from the emitting unit(225) and a signal including a nonlinear distortion component. A temperature sensing unit(235) optically connects to the emitting unit(225) and measures a peripheral temperature of the emitting unit(225). A microprocessor(240) receives a temperature value measured in the temperature sensing unit(235), reads level and phase change data corresponding to the measured temperature value from a memory unit, and corrects a coupling signal outputted from the optical detecting unit(230). The first gain adjusting unit(250) receives the coupling signal outputted from the optical detecting unit(230) and the level and phase change data provided from the microprocessor(240), amplifies the coupling signal to adjust a gain as a signal with a uniform amplitude, and inverts a phase of the adjusted signal at 180 degrees. The third coupling unit(255) combines the signal outputted from the variable signal generating unit(210) with the signal outputted from the first gain adjusting unit(250). The second gain adjusting unit(260) minutely adjusts the signal outputted from the third coupling unit(255) and adjusts a level and a phase for having a uniform amplitude. The second coupling unit(220) combines the signal matched in the input matching unit(215) with the signal outputted from the second gain adjusting unit(260) and provides the combined signal to the emitting unit(225).
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