They can be jammed, but they’re not as likely to be. I would have them remote-piloted, not completely autonomous. That way the drone only needs enough brain to manage flight surfaces and tactical-level maneuvering. That also allows for the remote pilot to have at their disposal an array of programmed “evasive” maneuvers, like a video game “combo”, that can be executed during combat, with the onboard logic system available to execute the actual maneuver and regain aerodynamic control afterwards.
Additionally, a remote-piloted UCAV with guns and bombs is easier to destroy if compromised, and will not yield anything of true value to an opponent possessing the technology necessary to bring one down intact.
Definitely. Two complimentary solutions to that. One, anti-radiation missiles. You emit (to jam), you die. Second, autonomous control. Have enough smarts on board the UAVs to complete the mission, or at least RTB, without active control.
However, I think piloted aircraft are a long way from gone. No UAV operator can match the reflexes and situational awareness of the guy with his but in the seat.