Ðè¿í´ø·½ÃæÓëFMϵͳÓкβ»Í¬¡£
? ²é¿´²Î¿¼´ð°¸
o
5-8£®ÒÑ֪ijµ¥Æµµ÷Ƶ²¨µÄÕñ·ùÊÇ10V£¬Ë²Ê±ÆµÂÊΪ
f(t)?106
?10cos2??10t(Hz)43
ÊÔÇó£º
£¨1£©´Ëµ÷Ƶ²¨µÄ±í´ïʽ£»
£¨2£©´Ëµ÷Ƶ²¨µÄƵÂÊÆ«ÒÆ¡¢µ÷ƵָÊýºÍƵ´ø¿í¶È£»
3
£¨3£©Èôµ÷ÖÆÐÅºÅÆµÂÊÌá¸ßµ½2¡Á10Hz£¬Ôòµ÷Ƶ²¨µÄƵƫ¡¢µ÷ƵָÊýºÍƵ´ø¿í¶ÈÈçºÎ±ä»¯£¿
? ²é¿´²Î¿¼´ð°¸
o
5-9£®ÓÐ60·ģÄâ»°ÒôÐźŲÉÓÃÆµ·Ö¸´Ó÷½Ê½´«Êä¡£ÒÑ֪ÿ·»°ÒôÐÅºÅÆµÂÊ·¶Î§Îª0¡«4kHz (ÒÔ
º¬·À»¤Æµ´ø£©£¬¸±Ôز¨²ÉÓÃSSBµ÷ÖÆ£¬Ö÷ÔØ²¨²ÉÓÃFMµ÷ÖÆ£¬µ÷ÖÆÖ¸Êý
(1) ÊÔ¼ÆËã¸±ÔØ²¨µ÷ÖÆºÏ³ÉÐÅºÅ¿í´ø£»
(2) ÊÔÇóÐŵÀ´«ÊäÐźŴø¿í¡£
?
²é¿´²Î¿¼´ð°¸
mf?2¡£
o
5-10£®½«µ÷·ù²¨Í¨¹ý²ÐÁô±ß´øÂ˲¨Æ÷²úÉú²ÐÁô±ß´øÐźš£Èô´ËÂ˲¨Æ÷µÄ´«Ê亯ÊýH(w)Èçͼ5-3
Ëùʾ£¨Ð±Ïß¶ÎΪֱÏߣ©¡£µ±µ÷ÖÆÐźÅΪm£¨t£©=A£¨sin100t+sin6000t£©Ê±£¬ÊÔÈ·¶¨ËùµÃ²ÐÁô±ß´ø
Ðźŵıí´ïʽ¡£
ͼ5-3 ?
²é¿´²Î¿¼´ð°¸
o
ft5-11£®Ä³µ÷ÖÆÏµÍ³Èçͼ5-4Ëùʾ¡£ÎªÁËÔÚÊä³ö¶Ëͬʱ·Ö±ðµÃµ½f1?t?¼°2??£¬ÊÔÈ·¶¨½ÓÊÕ¶Ëc1?t?µÄ
ºÍc2?t?¡£
ͼ5-4 ?
²é¿´²Î¿¼´ð°¸
µÚÁùÕ Êý×Ö»ù´ø´«Êäϵͳ
±¾ÕÂÖ÷ÒªÄÚÈÝ£º
£¨1£©Êý×Ö»ù´øÐźÅÓëÆµÆ×
£¨2£©AMIÂë¡¢HDBÂë¡¢PSTÂ롢˫ÏàÂëµÄ±àÂëÔÀíºÍÖ÷ÒªÓŵã
3£¨3£©Âë¼ä´®Èż°ÄοüË¹ÌØµÚÒ»×¼Ôò £¨4£©ÎÞÂë¼ä¸ÉÈÅʱµÄ»ù´ø´«ÊäµÄ¿¹ÔëÉùÐÔÄÜ £¨5£©¸ÄÉÆÏµÍ³ÐÔÄܵÄÁ½ÖÖ´ëÊ©¡ª¡ª²¿·ÖÏìÓ¦ºÍ¾ùºâ £¨6£©Ö±¹Û¹À¼Æ½ÓÊÕÐźÅÖÊÁ¿µÄ·½·¨¡ª¡ªÑÛͼ
±¾ÕÂÖØµã£º 1£®ÕÆÎÕ
AMIÂëºÍHDBÂëµÄ±àÂë·½·¨
32£®ÕÆÎÕÄοüË¹ÌØµÚÒ»×¼Ôò£¬¼´»ù´ø´«ÊäÌØÐÔÎÞÂë¼ä¸ÉÈŵÄÅжϷ½·¨ 3£®ÄÎÊÏ´ø¿í¡¢ÄÎÊÏËÙÂÊ¡¢ÐŵÀ´ø¿í¡¢ÐŵÀÀûÓÃÂʵļÆËã 4£®ÕÆÎÕµÚÒ»ÀàºÍµÚËÄÀಿ·ÖÏìÓ¦±àÂë·½·¨ 5£®ÕÆÎÕʱÓò¾ùºâÆ÷µÄÉè¼Æ·½·¨
±¾ÕÂÁ·Ï°Ì⣺
6-1£®Éè¶þ½øÖÆ·ûºÅÐòÁÐΪ10010011£¬ÊÔÒÔ¾ØÐÎÂö³åΪÀý£¬·Ö±ð»³öÏàÓ¦µÄµ¥¼«ÐÔ¡¢Ë«¼«ÐÔ¡¢µ¥¼«ÐÔ¹éÁ㡢˫¼«ÐÔ¹éÁã¡¢¶þ½øÖƲî·Ö²¨ÐκÍËÄµçÆ½²¨ÐΡ£
?
²é¿´²Î¿¼´ð°¸
o