There is nothing like "Low End" or "High End".
Before AESA/PESA, the radars used to be steered towards different directions to scan the area because of their limited field of view this mechanism of physically steering the antenna is Mechanical steering. But AESA/PESA changed this because the beams of radio waves can be electronically steered to point in different angle without moving the antenna, this is Electronic steering. Both are used to increase the field of view(FOV).
Electronic steering has a limitation, steering of more than about 60 degrees off the perpendicular causes a dropoff in performance and above that dropoff is quite drastic which leave it unusable. So to get the better coverage there are three approaches.
1-
Gimble Mount:
This is simple mechanical/hydraulic driven mount used on previous generations of radars. Just like its being used on KLJ-7(V2) right now.
This will increase the FOV to 240 Degrees and could maintain the best performance on most angles.
The downsides are; the delay in the scan of full FOV refresh based like previous generations, increase in weight, less reliable/increased failure points because of number of components involved, not as compact and maintaince intensive comparatively.
Irbis-E is devleoped following this route.
2-
Side/Cheek Arrays:
In this approach fornt got one fixed array and multiple smaller arrays are attached to the sides.
This increases the FOV to 300+ Degrees, FOV scan is instant, lest failure points and most reliable with graceful degradtion.
The downside are; side array's performance is not as good as fornt array so the increased angle will have lesser quality i.e. KLJ-7A front array got 1K+ TRMs and side arrays got ~600 TRMs so the quality of performance will not be equal on the sides. It like having a HD OLED screen in middle and non-HD LCD sides (i.e. resolution diffrence). This approch is power, cooling and processing power hungry, because as the number of TRMs increases so does the power consumption and require more cooling, more cooling needs more power. Also When TRMs are increased it produce more data which needs more processing power will require more time to refine data and this will need more power and cooling. So a single array will perform at its best quality with best speed in limited resourses rather then mutliple arrays.
F22, J20 and KLJ-7A etc are using this approch.
3-
Swach/Angled Array:
In this approach Array is attached to a plate which is angled(usually 45 Degrees) which rotates.
This increases the FOV to 210+ which is equilent to Gimble approach but its alot more reliable/lesser points of failure because their are lesser parts and rotaing can be extremly realiably for extened peroids of times. This approch decrease the need of maintaince. This approch is better than Side/Cheek array because it requires lesser power, cooling and processing. So the radar can work for longer duration on max performance with extreemly good quality while keeping up the speed. The performance will be also more uniform than Gimble and Side array approch. The scan refresh rate will be near instantaneous. Its more compact than the gimble. So this is the smartest approch which is being used by most of the new genration radrs.
This approch is being used by Typhoon, Gripen etc.
PAF has selected the best approach which will give the best performance with the best quality at all times reliably. So this is the best approach for JF-17. KLJ-7A is a generation ahead of other radars which have been previously developed just because of the advancement in technology. It's a GaN-based radar with compact modules of 20W power each and got 1K+ TRMs.
Essentially PAF has got there love back in form of JF17. PAF must go for in-house production as we gonna make at least 150 more aircrafts for our need.
