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什么是无线电?无线电是对无线电波使用的通称。它通过电磁场的振荡在空中传送信号,不需要导线。无线电波和阳光一样都是电磁波的一种,只是它比阳光的波长更长,频率更低一些。它是频率在3000GHz以下的电磁波。无线电波既有天然产生的,如雷电、太阳黑子活动、宇宙天体产生的无线电波;也有人为产生的,如手机、微波炉、广播电视发射台、雷达等各种人造设备产生的无线电波。
What is a radio? Radio is a generic term used for radio waves. It transmits signals over the air through the oscillation of the electromagnetic field, without wires. Radio waves and the sun are the same kind of electromagnetic waves, but it is longer than the wavelength of sunlight, lower frequencies. It is the electromagnetic wave frequency below 3000GHz. Radio waves are both naturally occurring, such as lightning, sunspot activity, the radio waves generated by cosmic objects; there are also man-made, such as mobile phones, microwave ovens, radio and television stations, radars and other man-made equipment generated radio waves.