The KJ-500 is the newest version of China's airborne early warning aircraft based on the An-12/Y-8/Y-9 series of transport aircraft. It's main radar antenna is housed in a .circular fairing on top of the aircraft. This does not house a rotating antenna, as earlier AEW types with a similar-looking "rotodome" do, but a triangle of antennae with electronically scanned beams.
The similar ZDK-03 has been exported to Pakistan, with a different radar.
has more information about the original.