The Ku-Band as defined by IEEE is a frequency range from 12 to 18 GHz. IEEE uses letters to signify a range of frequencies from 1 to 170 GHz. The Ku-band is mostly used for satellite TV and for VSAT systems on ships.
Some Key Applications of the Ku-Band:
Fixed Satellite Service (FSS) (11.7 to 12.7 GHz): This is the part of Ku-band spectrum is used for Fixed Satellite Services. Almost every antenna dish ranging from 1 meter to 1.7 meter size is used for FSS band reception. Free-To-Air (FTA) satellite systems also use the FSS band.
Direct Broadcast Satellite (DBS) (12.2 to 12.7 GHz): This is the part of Ku-band spectrum used for Direct Satellite Broadcasting. This band is reserved for high powered satellites intended for the delivery of digital television.
Key Points of the Ku band:
• The wide spacing between satellites allows for very high powered transmissions which results in the ability to use smaller dish antennas for VSAT applications.
• Ku band incurs lesser terrestrial interference.
• The wavelength of the Ku-Band from 16.7 to 25 mm starts to see some signal attenuation due to rain drops. This effect gets worse as you go above the Ku-Band wavelength to the K-Band.
Click here to see the other IEEE/Radar Letter Frequency Bands. 
Ku Band described by using NATO
NATO had a separate frequency band notation machine which is now obsolete. They additionally had a frequency band represented via the letter Ku. This band had a frequency vary from 10.9 to 20 GHz. “Ku” stands for “Kurz unten” – German for the band simply below the “short” or K-band (which begins at 20 GHz).
