Patent ID: 8638540

Claim:
A corona igniter ( 20 ) for providing a radio frequency electric field to ionize a portion of a fuel-air mixture and provide a corona discharge ( 24 ) in a combustion chamber ( 22 ), comprising: a housing ( 34 ) including a plurality of walls ( 40 , 42 , 44 ) presenting a total housing volume therebetween, a coil ( 26 ) disposed in said housing ( 34 ) for receiving energy at a first voltage and transmitting the energy at a second voltage higher than the first voltage, an electrode electrically coupled to said coil ( 26 ) for receiving the energy and providing the radio frequency electric field, a coil filler ( 36 ) formed of a resin material disposed on said coil ( 26 ), said coil filler ( 36 ) having a filler volume being a portion of said total housing volume, a capacitance reducing component ( 38 ) having a relative permittivity of less than 6 disposed in said housing ( 34 ), said capacitance reducing component ( 38 ) having a component volume being a portion of said total housing volume and being greater than said filler volume.