The spy aegis radar system has evolved as technology improves allowing more functionality in less space. The cruisers got the first versions, then were upgraded. The destroyers got spy-1d which was smaller and slightly shorter range. Spy-1f was put on Spanish f-100 frigates and is even smaller and shorter range. There are other versions as well.
Basically, as power requirements went down, and sensitivity went up and physical size went down, the antennae could be placed closer to each other. Also, larger ships still use air search radars like sps-49 to see up higher than the spy can.
Spy-6 is the next version to be installed on all the ships, but will take time as each ship goes through refit. It has a modular antenna system that can be scaled to fit the ship.
Global security.com has good info. Fas.com. Lockheed Martin. Just google spy-1 evolution.
I was wondering if anyone had any insight as to why the USN seems to have gone away from distributing the location of the AN/SPY-1 (and other similar radars) like is found on TICONDEROGA to the more compact installations we see on BURKE-class ships?
The 1960s/1970s Sea-based Anti-Ballastic Missile Intercept System (SABMIS) had their phased array radar split between the forward and aft part of the ship. TICONDEROGA cruisers were similar in their AN/SPY-1 was split 2 arrays forward and 2 aft, as did the proposed Guided Missile Cruiser Baseline and Strike Cruiser.
With the introduction of the BURKE-class, all the arrays are concentrated. A proposed ABM version of SAN ANTONIO (LPD-17) shows all the arrays concentrated forward, as well.
It appears the USN decided it as no longer worth the price to prevent a single hit from potentially mission-killing the ship. I suppose a single hit might do enough damage so that even those arrays are left intact they would still be inoperable due to other damage.
Does anyone have any documentation that explains the change?