Active Phase Target Illumination Radar any advantage?

What is the advantage of an active phase array missile fire control radar over the doppler radar varieties. Compare the Australian CEA-MOUNT active phase fire control radar for SM2 and ESSM and the THALES STIR HP X-band doppler fire control radar. Basically I just wanna know if the active phase one can direct more missiles than the doppler, so you can just buy 1 active instead of 2 doppler to direct 8-10 missile engagements.

I hope you guys can give me answers. Thanks in advance. 🙂 🙂