Why limit yourself to 20mm-40mm when obviously all turrets, be it small RWS or up to tank turrets, are following the same trends?
2 decades ago, turrets would consist of usually just 3 key components:
3)FCS for ballistic calculations only.
In 2006, the paradigm changed when APS started maturing and were about to enter service. By 2019 there are already hundreds of turrets in service with an integrated APS.
But that's not all.
APS are revolutionary not only because of the massive added protection, but because they turn the previously sight-heavy sensory suit to a hybrid one consisting of radars as well.
In 2016 the next paradigm change came with the introduction of revolutionary, instead of evolutionary, sighting systems that give crews the capacity to receive substantially more data, and along with that, removes some of the key advantages of manned turrets, in a time where unmanned turrets already had a substantial edge. The key arguments for unmanned turrets are greatly increased internal volume for IFVs, increased safety for MBTs (no crew deaths in catastrophic kills), and ease of communication between the crew members.
The key argument for manned turrets is the ability to fight with open hatches and see the battlefield for better situational awareness. That argument is basically gone with modern sight systems such as Elbit's IronVision or BAE's BattleView 360.
Yet another paradigm change is being pushed by the American NGCV program's OMFV, and Israel's Carmel.
This one includes sensor fusion, autonomous driving, and vastly reduced task load via assistive or completely autonomous processes.
The radars no longer merely detect a threat after a projectile is launched, but are used to scan the terrain.
Other sensors like LIDAR, optics, and acoustics, will scan the terrain as well, and detect targets both before firing and after firing.
All these, together with the radar and other potential sensors I haven't listed, will simultaneously scan the terrain and detect targets via sensor fusion algorithms in order to increase reliability and resolution, and reduce false alarms.
If you want to stay ahead of the competition, all these are a must to integrate on modern turrets. Some of this tech is not yet mature for immediate implementation, but feasibility was demonstrated very clearly.
You want my opinion on what should be the NEXT paradigm change? Multi-layered, multi-effector APS.
Imagine in 2030 when tech allows ground vehicles to operate systems with huge power output requirements.
The top layer APS would be a high powered laser that would be able to defeat missiles and artillery projectiles from a long range, capable of dealing with fairly high saturation.
The next layer would involve a Quick-Kill style missile launcher that would send small missiles to defeat KEPs/LRPs.
Next layer is an Iron Fist style system to defeat all target types at the short-medium range.
Final layer is an ADS/RAP or Trophy Lite style system (static interceptors) to defeat projectiles in the terminal stage.
Overburdened platform you say? Well not at all. The rotating launchers can be placed on the turret, i.e the laser and Iron Fist style APS.
The rest, Quick Kill and static interceptors, placed on the hull.
They will share effectors with other systems, for example the MGs will be able to try and shoot the target projectiles, even if the probability of hitting is not very high it can still help. Or in case of nearby hostile infantry, VBIEDs, or other immediate hazards, some APS effectors could be activated if the main weapon systems are either busy or would not respond quickly enough.
But the more important aspect is the fact that with longer range APS, it will be possible for AFVs to increase their ability to protect convoys of unprotected vehicles like logistics.
It will provide a full new layer of defense for such vehicles, that previously had to rely on evasive maneuvers as their last line of defense, which was greatly mitigated by their almost nonexistent ability to detect attacks.
And another thing I want to add, is exportation of sensors. Every AFV should be able to deploy sensors via any means available. Importation of data is already enabled via BMS, but exportation of sensors, whether via tethered or untethered drones, is still only being talked about.
And finally, it's not just about the turret, but what layers of weapon systems, defensive systems, sensors, and data analysis tools you have.