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频率变了就是非线性了...
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# A8 g' V7 A- j$ H# C举个例子x(t) = cos (2pi*f*t)$ L' [& V8 T U* s
非线性变换(平方律) y(t) = x(t)^2 = 1/2 + cos(4pi*f*t)/29 |% |1 f3 a; V/ q6 o7 s
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线性是指 x(t) = acos(2pi*f*t)
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会加大线性失真,减小非线性失真。: {0 H: L9 }! q
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Freq(out) = k x Freq(in) 就是线性,不满足就是非线性。9 h) x) r4 L2 P* b" Z+ ^
Timme 发表于 2008-12-31 22:39 ![]() |
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