Would it be difficult for a drone to utilize a directional antenna that stays homed into and pointed in the direction of the controller on the ground?

Tracking directional antena is typicaly on the ground station , as its a bit to much weight and size to use on small drones.

Meawhile it seems Russians will be fielding 'Breakwater' drone jamers on tanks soon, as the jamming range is between 600-1000m it could protect from FPV drones not just individual tank but a groups of vehicles.

That's why I am wary of "DRONES ARE THE FUTURE!!!" hysteria. I wouldn't be surprised if the Russians can make and field this jamming system. If so, you'll need home-on-jam weapons, probably something like an updated SIDEARM. Which will be most likely launched from a manned platform.

Sword and shield in constant battle, jammers will shut down FPV and other remote-piloted drones very effectively,an this is not energy demanding EW is using about 70W per effector( it can easily drown out 2w transmission that is good for 100+km FPV are not even on 1W they are in 0.6 Watt transmitting power, but next-gen drones with AI will not care about jamming as they will not be under manual control when they enter jamming field,

The problem is how much do you allow AI to kill on its own , ethical limitations, not technological. As at one point AI might kill a lot of blue force on its own , then what? 

Not so wild guess? GPS + INS recon drones, keep the range short, download pictures with Best Estimated Coordinates of Enemy Forces, fire lots of dumb or preferably DPICM at those coordinates.

Mr. T (MrT4) said:

The problem is how much do you allow AI to kill on its own , ethical limitations, not technological

I suspect at least in the West, the limitation will be AI is allowed to target military vehicles autonomously, but not individual humans. 

Similar to the capability the Brimstone missile has now, as well as other past weapons that could distinguish from civilian vs military vehicles/ships. 

That said, this would need some sort of geofencing for Ukraine, as it fields a number of basically identical systems to Russia. 

Brimstone has no capability of IFF , particularly in Ukraine where both sides use much the same gear brimstone is of limited use. You would actually need IFF systems built into every platform to enable AI work past very narrow coordiantes. Even with IFF Western Ad shot down more blue force aircraft than the enemy in wars so far ,Ukraine AD vs aircraft ,more than 30+% of the shutdowns are blue on blue, 

Currently and for some time to come AI will locate targets, inform a human operator, who then decides the course of action an AI is only free to act on the command given by a human operator, but i wouldn't count on much ethical restraint once things get going, its easier to just spin the narrative to fit the desired effect propaganda machine is still unrivaled.

Mr. T (MrT4) said:

Tracking directional antena is typicaly on the ground station , as its a bit to much weight and size to use on small drones.

The drone-mounted receiver might  be the analog to the ground station, or, potentially the opposite, something that shields the receiver from signals coming from the wrong direction.  I am more of a mechanical thinker so I tend to picture a swiveling device, but there is probably an easier way to accomplish this electronically.

As you can imagine even with directional conection a FPV signal that is at 0.6W can easily be drowned by jammer that is 100+x its power

But yes you are correct there are ways to protect somewhat from jamming, interesting way on GPS is to have ring fences around the GPS receiver prevent the ground-based interference from spilling over the fence, but GPS is looking up , with drones that are mostly LOS its much harder to protect from jamming, for now typical approach is to use non-comercial frequencies that are mostly covered by all the off the shelf jammers.

I have seen Russians are now tinkering with adapting base targeting or search radar  antena on Pantsir and Tor to act as an extremely strong jammer against drones, some of the frequency's radar works one are close enough that they think they could add a directional jamming function of extreme power, able to jam a drone at 20km without building a new system just adding functionality to the existing system. (remember when F35 was advertised to be able to use its AESA radar as Jammer , this is similar)

One thing I have wondered about is if we're going to see the elimination of IFF for MANPADS. With the deployment of more countermeasures for aircraft, that would help reduce reaction time for the target.