Yes, and I believe the "ramjet" intake rings behind the nacelle caps use this kind of technology (maybe the three thingies at the underside of the nacelles' front?).
This is a possibility as much as the ramscoop being the dome, as the rings are another feature commonly but not universally found in Starfleet nacelles. They are somewhat less common than the forward domes or windows, though, and disappear altogether from the most modern nacelles, those introduced in the various TNG movies. The domes stay, and are explicitly identified as the scoops on two designs: one with the rings (E-D), another without (E-E).
because it would be blocked by the forward deflector shield
Why? The nacelle forward ends are in rather prominent view from forward angles; a device for shielding the rest of the ship would not need to be blocking the path to the nacelles.
Interesting how the two hero ship types that do not have obvious nacelle domes are also the only two to have the nacelles at least partially hidden in forward view: the TMP variant of the Constitution
, and the Excelsior