Radio frequency: the abbreviation of radio frequency. Radio frequency is radio frequency current, which is a kind of high-frequency alternating electromagnetic wave, so it is called radio frequency for short, which means the electromagnetic frequency that can be radiated into space, and the frequency range is between 300 kHz and 300 GHz. Alternating current that changes less than 1000 times per second is called low-frequency current, and that that changes more than 10000 times is called high-frequency current, and radio frequency is such high-frequency current. High frequency (greater than10k); Radio frequency (300K-300G) is the higher frequency band of high frequency; Microwave band (300M-300G) is the higher frequency band of radio frequency. Radio frequency technology is widely used in wireless communication field, and cable TV system adopts radio frequency transmission mode.