When the signal spectrum falls into two or more channels, a method of spectrum assembling in frequency domain is used to obtain the positive or negative half spectrum.
在频域中当信号频谱处于两个或更多个滤波器通道时，通过频谱组合办法直接得到实信号的正半谱或负半谱。
2
The spectrum of amplitude modulated signal are two half magnitude spectrums of base band signal positive and negative shifted by a carrier or R. F. frequency.