| 摘要 |
PURPOSE:To improve the distortion rate of a demodulated signal by providing a band stop filter having frequency characteristics, which cancel the gain difference in a band of the frequency characteristics which a tuning light reception part has, on the reception side. CONSTITUTION:A band stop filter 26 having the frequency characteristics which cancel the gain difference in the band of the frequency characteristic which a tuning light reception part 22 has is provided on the reception side. That is, when FM infrared rays subjected to space transmission are received on the reception side, the output signal of the tuning light reception part 22 is the FM signal including an AM component because the frequency characteristics of the tuning light reception part 22 has the gain difference in the band. This FM signal is inputted to the band stop filter 26, which has the characteristics which cancels the gain difference in the band, and has the AM component eliminated and is demodulated to a data signal by a demodulating part 23. Thus, the AM component of the reception FM signal is eliminated to improve the distortion rate of the demodulated signal. |
