The Starship Voyager was designed by Rick Sternbach over the course of almost a year, starting in September 1993, when Star Trek: The Next Generation entered its final season.
Forgotten Trek has detailed Sternbach’s design process here. But there were other designers who contributed to the new ship.
Doug Drexler, who was working on Deep Space Nine at the time, submitted several ideas. So did Jim Martin. Their concepts give us a glimpse at what might have been.
Drexler’s were low-resolution computer-generated images. One shows a long, dart-like primary hull that matched Sternbach’s thinking. Another — the one with the ring-shaped warp drive — would become his starting point for the design of the Vulcan Suurok-class cruiser of Star Trek: Enterprise almost a decade later.
Martin’s hand-drawn sketches are reminiscent of the Defiant, which he had designed for Deep Space Nine. One looked like an updated version of the Oberth class. Another appears to have influenced the design of Chakotay’s Maquis raider, which appeared in the Voyager pilot “Caretaker”.