Although I still remain fond of the idea of the original Daedalus being an attempt at using spatial distortion as a ship defence, I suppose shield projectors utilizing transporter tech are the favoured bits of kit. The shields they produce would then probably be based on something akin to a transport pattern that requires re-inforcement. Something "in between" pure energy and solid matter would be generated - maybe the great grand-daddy of holo-matter. I don't see some pure energy type gizmo being an effective shield anymore than sunlight shields against radio waves.
Something that was cooked up starting in 2147 would have a couple of decades or so of transporter development to draw from and wouldn't require any more matter-energy manipulation than "protein re-sequencers". They'd then have a couple of centuries of steady progress in manipulation of forcefields to cobble together holodecks and other related techno-flummery.
My main goal in all this supposition is to help create a trek tech history that sort of flows together. We used to have a Tuesday morning general seminar class in physics at the U. of Waterloo where they'd show James Burke's "Connections". I suppose it stuck with me.
