free-electron
free-running
free-space
freeze
freezing
freight
FREJID
French
freq
FREQMULT
  frequency
frequency-amplitude
frequency-converting
frequency-dependent
frequency-division
frequency-hopping
frequency-identification
frequency-measuring
frequency-modulated
frequency-response
frequency-selective

    frequency mixer stage

    каскад смесителя частоты, каскад преобразователя частоты