C-band is not generally used for missile targeting guidance. Except for one missile --- Raytheon's Patriot missile and the MPQ-53 system.
Then when the Chinese air defense radars like HT-233 and the SJ-321 were revealed to be using C-band rather than the X-band the S-300's Flap Lid and Tombstone uses, analysts concluded that the HQ-9 and HT-233 were copying the Raytheon system, including the Patriot's guidance system using C-band illumination. This despite the HQ-9 rocket frame is more similar to the 5V55 missile frame of the S-300 system, and that the HT-233 has similarities to Flap Lid and Tombstone as well, in particular with their horn feeds.
When the naval versions of the HQ-9 were revealed, it is believed that it should follow the land version and use a C-band illumination and guidance. So it goes that there has to be, or needs to be a C-band illuminator within the Type 346 radar on the Type 052C, given the ship's absence of any external indication of such a device.
The danger to all this, is that this might be a myth in the making, and it doesn't help because of Jane's, white papers, and other defense media perpetuating the same narrative over and over again, that it seems passed as fact. The only thing that is officially revealed about the missile are information displayed with placards on defense exhibits for their export versions.
The second image shows that it is not the HQ-9B/FD2000B that is first mentioned with the active homing seeker, but the original HQ-9/FD2000 itself.
That is as far as the official information goes and the only bit of official information available.
Here is another example of how a misconception can happen. This involves the SJ-321, which is a copy of the HT-233 and used to support the HQ-12 missile, also known as KS-1.
Specifications (CASIC):
Operating band: C (G/X) band
Radar cross section: 2m2
Maximum detection range: ≥120km
Minimum detection range: 3km
Operational performance: Altitude: 0.05~27km
Slant range: 5~70km (120 km)
Maximum operational airspace: Azimuth: 0~360º (mechanical rotation range)
-30º~+30º (electrical scanning range)
Elevation: -1º~+70º (electrical scanning range)
Target capability:
Guide 4~8 missiles to intercept 4 targets at the same time
"The SJ-231 guidance station is an important constituent part and the operational command and control center of the KS-1A weapon system. It is used to detect and track the aerial target and control and guide the missile. The SJ-231 guidance station is an advanced guidance radar system and is developed according to the modern war characteristics and the modern air-defense combat requirements. During the development of the guidance station, many advanced techniques in the radar technique development since 1990s are applied to improve the technical performance of the SJ-231 guidance station to a new level."
Given this kind of language, this seems suggestive, or proof that the SJ-321 uses C-band for missile target illumination, like a semi active homing system or TVM. But one has to remember that these are written by people who are not native English speakers. The word "guidance" itself is very vague and can mean a lot of things.
The SJ-321 is used to guide the HQ-12/KS-1A missile, and it turns out this is how the missile really works as per official literature.
So guidance as it turns out, is command guidance for this particular missile and its radar set, a bit of a departure from MPQ-53 copy narrative. The radar set does not target illuminate for a seeker. Rather it tracks the target closely and tells the missile where to go at it.
The preoccupation that missile guidance = SARH illumination can be very misleading, especially when you are trying to form "Chinese Aegis" is going to work like AEGIS which has SARH illuminators.
