An RF device is provided. The RF device includes a vibratile carbon nanotube having a nanotube natural frequency (f0), a negative electrode fixed to a first end of the carbon nanotube, a vibratile tuning electrode having a variable resonance frequency and facing a second end of the carbon nanotube, and a positive electrode electrically connected to a first end of the tuning electrode. A second end of the tuning electrode is adjacent to the second end of the carbon nanotube, and the carbon nanotube vibrates at a carrier frequency according to an external electromagnetic wave having the carrier frequency, and the tuning electrode having variable resonance frequency characteristics amplifies distance variation between the second end of the carbon nanotube and the second end of the tuning electrode to increase an electron emission sensitivity according to field emission.