| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a PON system in which burst signals with different transmission speed are mixed and which has high receiving sensitivity, wide dynamic range characteristics, and high-speed responsiveness. <P>SOLUTION: An optical receiver includes: a light receiving element 10; a preamplifier 11 which converts a current signal into a first voltage signal to perform gain control based on transmission speed; a control circuit 12 which varies a time constant based on the transmission speed to continuously control a gain of the preamplifier 11 by first average voltage which is average voltage of the first voltage signal; a LPF 13 which varies a pass band based on the transmission speed to output a second voltage signal using the first voltage signal as input; a second detection circuit 14 which varies the time constant based on the transmission speed to detect average voltage of the second voltage signal to be output as second average voltage; and a limiting amplifier 15 which amplifies difference voltage between the second voltage signal and the second average voltage and outputs it. <P>COPYRIGHT: (C)2010,JPO&INPIT |
