The repetition rate of a periodic signal, expressed in cycles per second. The units of frequency are Hertz (Hz).

common multipliers include:

Hz (hertz):  1 cycle per second
kHz (kilohertz):  10³ Hz
MHz (megahertz) : 10⁶ Hz
GHz (gigahertz): 10⁹ Hz
THz (terahertz): 10¹² Hz
PHz (petahertz): 10¹⁵ Hz
EHz (exahertz): 10¹⁸ Hz

Most Agilent Technologies products are designed to operate in the MHz to GHz frequency range.

see also: Frequency Bands
U.S. frequency allocation table published by the FCC, March 1996
European frequency allocation table for 950 MHz to 150 GHz published by CEPT, March 1995