US Patent 9359990 Plasma generating device and internal combustion engine

The size of the plasma produced by a plasma-generating device that generates plasma using electromagnetic (EM) radiation is enlarged. The plasma-generating device has an EM-wave-generating device that generates EM radiation, a radiation antenna that emits the EM radiation supplied from the EM-wave-generating device to a target space, and a receiving antenna located near the radiation antenna. The receiving antenna is grounded such that an adjacent portion that is close to the radiation antenna has a higher voltage while the EM radiation is emitted from the radiation antenna. The plasma-generating device generates plasma in the target space near the radiation antenna and the adjacent portion by emitting EM radiation from the radiation antenna.