[Goose]

How much of a radar return is there from a quad copter carrying say a 20 kg weapon load? I have always assumed that these weapons would be flown and target on local targets.  Is there any kind or real radar return off these smaller drones?

Not much, but "enough" in many cases. An AWACS in general won't see it at any reasonable range. It isn't so much that it is a very small target (which it is), but rather it is too slow. The Doppler shift due to target velocity will be at too low a frequency to filter it out from ground clutter. However, the relatively short range of such weapons does mean that simple and "low" power radars looking "up" at a say 15 degree elevation can see these targets, because they are "close" and the free space path loss is small. This type of detection can direct both kinetic weapons (guns) and directed energy weapons (lasers and high power microwave transmitters) at these types of targets. It turns out that there are also some ultra-wide-band (UWB) radars that work very well on these types of targets. The trick is to build an antenna that will support the bandwidth. Work is ongoing.

[Goose]

How much of a radar return is there from a quad copter carrying say a 20 kg weapon load? I have always assumed that these weapons would be flown and target on local targets.  Is there any kind or real radar return off these smaller drones?

Not much, but "enough" in many cases. An AWACS in general won't see it at any reasonable range. It isn't so much that it is a very small target (which it is), but rather it is too slow. The Doppler shift due to target velocity will be at too low a frequency to filter it out from ground clutter. However, the relatively short range of such weapons does mean that simple and "low" power radars looking "up" at a say 15 degree elevation can see these targets, because they are "close" and the free space path loss is small. This type of detection can direct both kinetic weapons (guns) and directed energy weapons (lasers and high power microwave transmitters) at these types of targets. It turns out that there are also some ultra-wide-band (UWB) radars that work very well on these types of targets. The trick is to build an antenna that will support the bandwidth. Work is ongoing.