US Patent 9920737 Internal combustion engine

In an internal combustion engine that causes a predetermined gas flow in a combustion chamber, discharge plasma generated by a discharge device is caused to effectively absorb energy of an electromagnetic wave emitted from an electromagnetic wave emission device. At a time when a discharge operation and an emission operation are simultaneously performed so as to ignite a fuel air mixture, an emitting position of the electromagnetic wave on an antenna during the emission operation is located downstream of the discharge gap in a direction of the gas flow at the discharge gap so as to face toward the discharge plasma that has been drifted due to the gas flow.