【文章內(nèi)容簡介】
wRdwRwXjdwXwRjwwwjXwRtUFthFwjXwRthFwH???????????????????????????????????)(1)(,)(1)(])(212/)([])(212/)([)1)((*)]()([21)]([*)]([21)()()]([)(???? dtftfH ? ?????)(1))((從而可知:希爾伯特變換與反希爾伯特變換只相差一個(gè)負(fù)號(hào)。 時(shí)域上有相同的定義: 模擬調(diào)制技術(shù) 18 6. 希爾伯特變換的性質(zhì) : (3) 若 f(t)的頻帶限于 cww ?||則有 )c o s ()())s i n ()(()s i n ()())c o s ()((twtftwtfHtwtftwtfHcccc???)c o s ())( s i n ()2()s i n ())( c o s ()1(???????????twtwHtwtwHcccc 模擬調(diào)制技術(shù) 19 )())((),())(()()()()()()(wRwXHwXwRHwjXwRwHtUthth???????證明: 頻域上: )())((),())(()()()()()()(tRtXHtXtRHtjXtRtwUww?????????? 模擬調(diào)制技術(shù) 20 )s i n ()())c o s ()(()s i n ()()c o s ()()()()()()()(twtftwtfHtwtjftwtfetfwUwwFwwFwwFwcccctjwcccc??????????令: 可知: 隱含條件 f(t)為實(shí)函數(shù) 模擬調(diào)制技術(shù) 21 ( 4) . 若 F(w)為 f(t)的付氏變換,則 f(t)的 希爾伯特變換的付氏變換為 )s g n ()())](([ wwjFtfHF ?????????0101)s g n (www 模擬調(diào)制技術(shù) 22 : ?????????ccU S BSSBD S BSSBwwwwwRwRwHthtStS||0||1)()(1)()(*)()(ttwtdwewRdwewHthcjw tjw tU S BU S B)s i n (1)())(1(21)(21)(??????? ?????????? 模擬調(diào)制技術(shù) 23 ttwtwtftwtfttwttwtfthtStScccccU S BD S BU S B)s i n (1*)]co s ()([)co s ()(])s i n (1)([*)]co s ()([)(*)()(???????????????????????????)co s (