(+)Frequency correction

(+)Frequency-offset locked loop

(light-)frequency modulation

(Ultra) high frequency time series

~(87)Rb atomic frequency standard

10 kV frequency converter

2 GHz microwave frequency-changing

2-D optical frequency-time coding

2nd harmonic frequency

3060 day low-frequency oscillation

3D frequency domain potential theory

3-phase low frequency

4D time-frequency volume

4-level frequency modulation (4-level FM)

50hz Frequency Interference

50Hz power frequency interference

95% spetral edge frequency

A C frequency modulator speed govornor

A Frequency Distribution Table

a high frequency and efficiency regeneration syste