Why not? It’s a phased array, and the bandwidth is high, so you need a decent amount of RF power. The amplifiers aren’t very efficient at the kind of frequencies it operates at so that makes it worse!

For reference, a company I worked at produced a Ka-band (27.5-31GHz) block upconverter that produced 25W (this was used for geostationary mostly, usually with a 1m dish), and it could draw something like 200 W or more when saturated.