Earlier quoted context omitted.
Expanding on that, for interest: * https://en.wikipedia.org/wiki/Phased_array * https://www.globenewswire.com/news-release/2003/02/11/294058... * https://en.wikipedia.org/wiki/Multi-role_Electronically_Scan... * https://en.wikipedia.org/wiki/Boeing_E-7_Wedgetail
> https://en.wikipedia.org/wiki/Boeing_E-7_Wedgetail Somewhat interesting in that the Pentagon did not want the E-7 (as a replacement to the E-3): * https://www.twz.com/air/e-2-hawkeye-replaces-usaf-e-3-sentry... nominally because it wanted to spend the money on more E-2s, which can operate on smaller and rougher airfields, which would be handy in (e.g.) the Pacific where tiny islands don't necessary 'fancy' runways…
it is a reasonable point that any airborne radar is an attractive target to long-range missile. and that if your radar is in space, it's a different, less available class of missile to attack it (and also that so far treating space as contested is taboo).
the recent loss of THAAD radar should also make people rethink how to make an emitter that survives the first round of missiles.