| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve a prescribed processing to a high-frequency signal of two frequency bands demodulated from an optical signal by a simple constitution, and inexpensively. <P>SOLUTION: A photodiode 2 light-receives the optical signal modulated by a mixed signal of the high-frequency signals of a first and a second frequency bands, and a signal corresponding to the mixed signal runs to tap-having high-frequency blocking coils 4 and 10 connected in series holding the photodiode 2. A high-pass filter 18 connected to the tap-having high-frequency blocking coil 4 extracts the high-frequency signal of the first frequency band from the mixed signal. The high-frequency signal of the second frequency band is extracted from the mixed signal generated in the tap-having high-frequency blocking coil 10. An amplification and frequency characteristic adjusting circuit 20 connected to the high-pass filter 18 processes the high-frequency signal of the first frequency band from the high-pass filter 18. The amplification and frequency characteristic adjusting circuit 36 connected to a low-pass filter 34 processes the high-frequency signal of the second frequency band from the low-pass filter 34. <P>COPYRIGHT: (C)2007,JPO&INPIT |
