To my knowledge there isn’t something like this in Dead Rising but it smells of it. The Sci-Fi in CDDA is based off realistic things with just a touch of “Because” logic.
Demons? Depending on your religion of choice that’s one flavor of because or another, either-way it (sorta) works out
Zombies? It’s a zombie game, kinda need this “because” Besides, ask the right conspiracy groups and it’s not a “because” to them.
Teleportation? Another because that’s sorta paved over by the game’s science
Caseless ammo? It exists, has for awhile The H&K G11 (Why don’t we have this in game?)
Laser weapons? …Sorta exist, currently they’re not man portable (hell I think the only one that “works” requires a large building for it’s inner workings)
Powered Armor? Also exists, I’m sure you’ve seen the video on youtube and it’s not too unbelievable to see it in later years.
Mini-Nuclear Reactors & Advanced (Extremely Efficient) Solar Panels? We’re already on the edge of a fuel crisis, it’s not unbelievable to see this kinda tech being devloped in CDDA.
Just because it’s the future doesn’t justify something like your giant microwave. That said, this tech… KINDA exists as is… But not in the way you described:
Directed-energy weapon (DEW) - Microwave Weapons