2011年11月24日星期四
What is the principle of radio?
Radio is in free space (including air and vacuum) electromagnetic wave propagation, the frequency 300GHz or less (lower frequency than the non-uniform, in a variety of RF specifications book, the common three 3KHz ~ 300GHz, 9KHz ~ 300GHz, 10KHz ~ 300GHz). Radio signal by radio wave propagation techniques.
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