Quick answer
Ka-band is the radio frequency range from roughly 26.5 to 40 GHz, prized in satellite communications for the enormous bandwidth it offers. It carries most modern satellite broadband — including mega-constellation user and gateway links — at the price of greater vulnerability to rain fade than lower-frequency bands.
📘 Full definition✓ Reviewed 2026-09-07
Ka-band ("K-above") spans approximately 26.5–40 GHz, sitting above Starlink-era workhorse Ku-band in the microwave spectrum. Higher frequency means more usable bandwidth per channel and smaller antennas for the same gain, which is why high-throughput satellites and mega-constellations lean on Ka-band for their highest-capacity links — typically the gateway connections between satellites and ground stations, with satcom downlinks around 17.7–21.2 GHz and uplinks around 27.5–31 GHz. The trade-off is atmospheric attenuation: at these wavelengths, rain, and even heavy cloud, absorb signal significantly (rain fade), so Ka-band systems build in link margin, adaptive coding and site diversity — routing traffic to a gateway where the weather is clear. Spectrum in the band is allocated internationally by the ITU and is among the most contested resources in the satellite industry.
Frequency range
26.5–40 GHz
IEEE band definition
Satcom use
≈18–31 GHz
downlink ~17.7–21.2 · uplink ~27.5–31
Strength
Very high bandwidth
more capacity per channel than Ku or C
Weakness
Rain fade
mitigated by margin + gateway diversity
Understanding Ka-Band
The satellite frequency ladder
| Band | Range | Typical use |
|---|---|---|
| L-band | 1–2 GHz | GNSS, mobile satcom, IoT |
| C-band | 4–8 GHz | Legacy TV distribution, rain-resilient links |
| Ku-band | 12–18 GHz | TV broadcast, VSAT, user broadband |
| Ka-band | 26.5–40 GHz | High-throughput broadband, gateways |
| V/E-band | 40–75+ GHz | Next-gen feeder links, inter-satellite |
| Optical | ~200 THz | Laser inter-satellite links |
Why constellations climb the spectrum
Each generation of satellite broadband needs more capacity, and capacity lives in bandwidth. Ku-band offers a few GHz; Ka-band several times that; V-band and E-band above it more still. Mega-constellations typically serve user terminals in Ku- or Ka-band while running gateway feeder links in Ka-band and above, and increasingly move backbone traffic onto laser inter-satellite links, which sidestep radio spectrum limits entirely.