Ku band, ranging from 12-18 GHz based on the formal definition of radar frequency band nomenclature in IEEE Standard 521-2002 in radar applications, directly below K band on the electromagnetic spectrum of the microwave range of frequencies, divided into multiple segments by geographical region based on the International Telecommunication Unit (ITU), is the primary device for satellite communications.
Fixed and broadcast services are the most notable users of this band, plus the more specific applications of NASA’s Tracking Data Relay Satellite, used for both space shuttle and ISS communications. Aside from that, Ku band is also being used for backhauls and for satellites from a distant location back to a TV network’s studio for editing and broadcasting. An American TV network, NBC, or the “Peacock Network,” is the first to uplink a majority of its affiliate feeds via Ku band in 1983.
Ku band is not just for TV transmissions, but also for digital data transmission via satellites, and voice/audio transmissions. And in Europe, more than any other places, Ku band is being used for vehicle speed detection by law enforcement.
However, with all of this uses, like any other things, the Ku band system also has its downside. On the frequencies higher than 10 GHz, heavy rain easily degrades the system caused by and proportional to the amount of rainfall, known as rain fade. The higher the frequency of the band, the higher its susceptibility to signal degradation.
Rain fade is primarily the absorption of a microwave radio frequency (RF) signal by atmospheric rain, snow or ice. Its losses are prevalently apparent at frequencies above 11 GHz. Aside from that definition, rain fade is also the degradation of a signal caused by the electromagnetic interference of the leading edge of a storm front.
Snow fade, on the other hand, defined as when snow and ice accumulates significantly changes the focal point of a dish during the winter precipitation, is also one of the problems. The Ku Band satellites will usually require more power to transmit than the other satellites.
Today, rain fade can be solved by setting out an appropriate link budget strategy on designing the satellite network and allocating a higher power consumption to compensate rain fade loss. Also, through the super-hydrophobic Lotus effect coatings, both rain fade and snow fade can be reduced. The lotus effect is the very high water repellence shown by the leaves of a lotus flower. |
| Remove Links
