Hey Token,
re the active-radar seekers in Ukraine
I do not know much about the Russian based systems use by Ukraine, so cannot comment on their types of seekers.
However, all(?) the NASAMS use various Mods of the AMRAAM missile. The AMRAAM uses an active-radar seeker for the terminal phase, with mid-course guidance via SAR and/or TWS mid-course updates. Depending on the Mod of the AMRAAM it may use the launch aircraft's/or another data-linked aircraft's radar to indicate/help acquire the target during mid-course updates and the missile seeker's target acquisition phase. The latest NASAMS can use the AIM-9X (and possibly other AIM-9 Mods?) in place of the AMRAAM.
The Patriot has quite a few Mods for its radars and missiles. There are 3 basic 'Standard' missile blocks - Pac 1, 2, and 3. Pac3 all(?) have terminal active-radar seekers. There are also several 'hybrid' versions of the earlier Pac 1 and 2. Depending on the specific Mods incorporated (some are unique to the purchaser), a modified AMRAAM active-radar seeker may be fitted for terminal phase. For all but the earliest radars a change/update of software Mods (again, sometimes unique to the purchaser) will allow the operation of the 'hybrid' missiles.
The operation/launch profile of the Patriot when using the Pac 3 (or 'hybrid' Pac 1 and 2 with the modified AMRAAM active-radar seekers) can be similar to the AWG-9/Phoenix system as used by the (now retired) F-14 tomcat. In fact, some of the early Patriot hybrid systems systems used repackaged Phoenix active-radar seekers for the tests. How many and what specific Mods of the Pac 3 or 'hybrid' Pac 1 and 2 missiles have been supplied to Ukraine I cannot say. The same for the 'Standard' Pac 1 and 2 Mods. As with NASAMS, depending on the Mod the Patriot may use the launch Battery's radar or another data-linked radar to indicate/help acquire the target during mid-course updates and the missile seeker's target acquisition phase.
When using mid-course update mode (ie no continuous illumination/indicating) the Patriot radar (along with other similarly capable radars) are known to be particularly difficult to detect even in normal search mode, and there may be no detectable target lock-on signal when in TWS (Track-While-Scan) mode - especially if the target does not have updated RWR systems.
It should also be noted that various of the 'Standard' and 'Hybrid' Patriot missile Mods allow HOJ (Home-On-Jam) and HOE (Home-On-Emitter) for use vs airborne EW systems and radars. Some of the Mods would in effect act in a similar manner to ARMs (Anti-Radiation Missile) which are silent and give no warning of acquisition to the target.