2006-06-29 07:38:01 · 7 answers · asked by ahamed kamil 1 in Science & Mathematics ➔ Engineering
Because one of the main reasons of modulation is to shift a signal from one frequency band to another. Multiplication by a sinusoidal does this shifting directly because multiplication by a sinusoid in time domain is equivalent to a shift in frequency domain, this is one of the properties of fourier transform. Any other periodic signal other than a sinusoid will, in addition to the shift you want, introduce other "waste" or rubbish components at other frequency bands which may harm your system or someone else's. Got the point?
2006-06-29 12:48:54 · answer #1 · answered by sheriefhalawa 2 · 1⤊ 1⤋
Modulation can be any waveshape depending on the source the signal. I think your question is not about the modulation signal but the carrier that is being modulated which is most often a sine wave. The reason for that is a sine-wave carrier will occupy the least bandwidth no matter what is modulating it. Any other shape wave can be used as a carrier (for example, a square wave), but additional bandwidth is occupied by the harmonics.
2006-06-29 18:51:12 · answer #2 · answered by gp4rts 7 · 0⤊ 0⤋
A sine wave looks so stylish and in a super variety of the actual techniques, the sign would not start up with an entire amplitude of one million whilst time is 0. So, a sine wave represents the real existence greater powerful than a cosine wave. A tan wave is going to infinity and so is perplexing to symbolize.
2016-12-14 02:55:47 · answer #3 · answered by live 4 · 0⤊ 0⤋
A sine wave is a representation of pure freqeuncy . A Sin / Cos has only one frequency component . According to the Fourier Series / Transform , most other signals can be shown to contain many frequencies . Since the aim is to shift to another band / frequency , a Sin wave is used .
Cheers !
2006-06-30 07:16:08 · answer #4 · answered by Harish 2 · 0⤊ 0⤋
Bcoz Sine wave is simple and easy for observation.We can easiliy generated it from oscillator with precise frequency.RMS value of sine wave is unity.so easy for power calculation.We can easily tuned the modulating frequency for radio and other trasmitting applications.
2006-06-29 14:04:40 · answer #5 · answered by Cherma 2 · 0⤊ 0⤋
Because it's the easiest one to do the calculations on. If you doubt it, try another wave form, look at the Laplace or Fourier transforms, and you'll be convinced I think.
2006-06-29 07:43:39 · answer #6 · answered by Alan F 1 · 0⤊ 0⤋
Sine waves can be modified to be any graph (fourier analysis).
2006-06-29 08:41:56 · answer #7 · answered by N M 1 · 0⤊ 0⤋