I stumbled across an image of what is supposedly the active electronically scanned array (AESA) radar for the J-10B and J-20 at the Asian Defence News site. I have no idea as to the image's provenance (it is very likely a model), but a similar set was photographed on a J-10B test aircraft at Chengdu last year (below).
The structure around the radar suggests this is the mounting for the J-10. The real radar probably has several more boxes - note the amount of fuselage space occupied by the guts of Raytheon's APG-79 AESA set for the F/A-18 E/F Super Hornet (below).
The radar is also not hinged. Representatives of Eurofighter
and Gripen NG like to talk about how the AESA mounts on their aircraft can swing
left or right. They claim this improves the set's field of regard, and is an
advantage over the fixed mounts on aircraft such as the Super Hornet and
Rafale. A two ship formation with hinged AESAs can scan further to the left and
right, they say, and it improves an aircraft's ability's to 'look sideways'
over borders (or enemy lines).