The EM-drive would not create thrust from nothingness

Image I

There are three types of theoretical EM-drives, that can take humans to stars. The problem with those rockets is weak thrust, the thrust of the photon rockets is maybe 0,000000001 or even fewer newtons. In the same way, the weak thrust is a problem with electron and radio wave-based propulsion. All EM systems require high-voltage electricity. So the use of large size solar panels or nuclear reactors is required in those systems.

And that means none of those EM-engines can even operate in the atmosphere. The use of EM-engines is reserved only to outer space, and the craft must accelerate near the speed of light by using some other power source. The thing is that the EM-engines are at the same time weapons. And that means that some research on electromagnetic engines is covering weapon research. 

1) Photon rockets. 

Those rockets shoot photons to backward for making specific impulses of the speed of light. There are two types of photon rockets. Laser photon rockets what are using coherent light for making thrust. And the photon rockets, which are using regular light. 

The light can make by using powerful lasers or antimatter annihilation reactions. There has been introduced an idea that the engines use laser-rays for ionizing air, and then the ionized air would pull through the engine. Also, laser engines are planned to use to detonate small lithium capsules behind the spacecraft. That gives it more punch than just photons.  

Image II

2) The microwave engines. 

The EM-drive can also be the weapon, which mission is to jam satellites or close the internal communication signals of drone swarms. It can use radio- or microwaves for that mission, and the last ones could be one of the deadliest weapons in the world. The microwaves are not harmless. The microwaves can cause fire, detonate ammunition dumps or cause burning injuries and even death to people who are in the affected area of those systems. 

The microwave engines are similar to photon engines. They are using magnetrons for creating microwaves. When the microwaves are traveling backward, the recoil will put the craft travel forward. The fact is that the thrust of that engine is also a similar class to the photon rocket. 

There is the possibility that the thrust of those systems is improved by injecting hydrogen or water into the chamber. And microwaves are boiling it. In this system, the burning in the rocket chamber is replaced by using microwaves, what is boiling the propellant.  

3) Electron or ion engines (Ion thrusters)

Ion and electron engines are similar systems. They are using ionized atoms or electrons for giving thrust. The ionized or electrically loaded particles can drive through the particle accelerators. Those accelerators can give extremely high speed and specific impulses for the particles like protons. 

Or some metal ions, or electrons that are traveling through them. Those systems are already used in the probes, which are operating in the asteroid belt. The ion and electron engines are also promising tools for traveling in the solar system, but the stars are a little bit too far away for those systems. 

There have been plans to make the cathode engine that is similar to the antimatter engine in Image II. The electrons will shoot to anode plate that is ahead of the craft, and that thing makes it possible to give thrust for spacecraft. The cathode system can use before the antimatter engine is started, but the fact is stars are far away. 

()https://en.wikipedia.org/wiki/EmDrive

()https://en.wikipedia.org/wiki/Ion_thruster

()https://en.wikipedia.org/wiki/Photon_rocket

The image I:()https://magictorch.com/bbc-focus-the-next-giant-leap-for-mankind

Image II:()https://www.centauri-dreams.org/2009/06/03/antimatter-propulsion-a-critical-look/