For high speed algorithmic trading, see high-frequency trading. HF's position in the electromagnetic spectrum. High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 MHz.It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred metres).Frequencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band.requencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band.