《电路》（英文版）14-4 Line spectrum

8 14-4 Line spectrum A plot showing each of harmonic amplitudes in the wave is called the line spectrum. f(t) +∑I a cos nat+Vn sinnat n=1 f( ●鲁 0+∑ Cn cos(nar-9n) n=1 1010.10 丌2丌3兀4丌 10 Example:(14-1) an=5 and C=Vn2+b2=10/n兀.(n≥1 Co=ao and Cn=a+b (n21) line spectrum 2 f(t)=5-10 10 10 10 sinat sinon sin 3ot sin 4ot 2丌 3兀 4丌

§14-4 Line spectrum A plot showing each of harmonic amplitudes in the wave is called the line spectrum. [ cos sin ] 2 1 ( ) 1 0 f t a a n t b n t n  n  n   = = + +   = = + − 1 0 cos( ) n C Cn nt n Example: (14-1) ( 1) 2 1 2 2 C0 = a0 and Cn = an + bn n  5 10/ . ( 1) 2 1 2 2 C0 = a0 = and Cn = an + bn = n n  f t t t t t        sin4 4 10 sin3 3 10 sin2 2 10 sin 10 ( ) = 5− − − − 0 1 4 f (t) n 2 3  10 5 2 10 3 10 4 10 line spectrum