The Ka band is an electromagnetic frequency range which covers 26.5 – 40 GHz. The Ka band is a portion of the K microwave band, which ranges from around 18 to 40 GHz. ‘Ka’ is short for ‘K-above,’ denoting that this range approximately covers the upper third of the entire K band. The term ‘Ka’ frequently refers to the band with the recommended operating frequency of the WR-28 waveguide (within 26.5 – 40 GHz) .
The IEEE K band is segmented into three secondary bands:
- Ka (K-above) band – ranging from 26.5–40 GHZ, which is primarily used in experimental communications and radar
- K band – ranging from 18–27 GHz
- Ku (K-under) band – ranging from 12–18 GHz, mainly for radar, satellite communications, and terrestrial microwave transmissions
Downlink within the 18.3–18.8 or 19.7–20.2 GHz bands, communications satellites, and high-resolution close-range targeting radar (aboard military aircraft) use the 30/20 GHz band. The uplink for the 30/20 systems are around 30 GHz. This radar range is used for vehicle speed identification required by law enforcement.
The Ka band uplink frequencies are within 27.5–31 GHz, while the downlink frequencies are within 18.3–18.8 and 19.7–20.2 GHz.
Ka band satellites usually transmit using more power than C band satellites, although C band dishes are bigger than Ka band satellites. Ka band dishes range from 2 feet to 5 feet in diameter, while C band dishes range from 7 feet to 12 feet.
C band dishes are also known as BUDs (Big Ugly Dishes) due to their relative size. Conversely, due to the higher frequency range and smaller dish size, the signals are more prone to signal disruptions and quality problems caused by adverse weather conditions such as rainfall (recognized as rainfade).