A system for plasma ignition and maintenance of an atmospheric pressure plasma. The system has a variable frequency alternating current (AC) power source, a transformer, a cable connected to a secondary winding of the transformer, a programmed microprocessor for control of power to the atmospheric pressure plasma. The microprocessor is configured to a) at pre-ignition, power the AC power source at an operational frequency f.sub.op higher than the resonant frequency f.sub.r, b) decrease the operational frequency f.sub.op of the AC power source until there is plasma ignition, and c) after the plasma ignition, further decrease the operational frequency f.sub.op of the AC power source to a frequency lower than the resonant frequency f.sub.r.

A low-voltage plasma ionizer is proposed. The ionizer may include a resonator module comprising a metal plate and configured to generate plasma by using an electric field, wherein the metal plate comprises a long side extending in a longitudinal direction, a short side crossing the long side, and a slot extending in the longitudinal direction. The ionizer may also include a source generator connected to the resonator module, and configured to supply a signal to the resonator module to generate plasma including plasma ions around the metal plate. The ionizer may further include a fan placed in an XY plane, and configured to move the plasma ion in a direction crossing the XY plane.

A plasma-generation system is provided that includes a variable-frequency microwave generator configured to generate microwave power and a plasma applicator configured to use the microwave power from the microwave generator to (i) ignite a process gas therein for initiating a plasma in a plasma ignition process and (ii) maintain the plasma in a steady state process. The system also includes a coarse tuner connected between the microwave generator and the plasma applicator. At least one physical parameter of the coarse tuner is adapted to be set to achieve coarse impedance matching between the microwave generator and the plasma generated during both the plasma ignition process and the steady state process. A load impedance of the plasma generated during the plasma ignition process and the steady state process is adapted to vary. The microwave generator is configured to tune an operating frequency at the set physical parameter of the coarse tuner.

A method of providing spark ignition for an engine or other equipment having a combustion chamber. A radio frequency wave or a microwave (RF/microwave) generator delivers radio frequency waves or microwaves to a transmit antenna inside the combustion chamber. At least one RF/microwave receive antenna is attached to an internal surface of the combustion chamber and comprises two or more RF/microwave focusing features with a spark gap between them. The transmit antenna wirelessly energizes the receive antenna, which generates a spark between the two focusing features.

Embodiments disclosed herein include a high-frequency emission module. In an embodiment, the high-frequency emission module comprises a solid state high-frequency power source, an applicator for propagating high-frequency electromagnetic radiation from the power source, and a thermal break coupled between the power source and the applicator. In an embodiment, the thermal break comprises a substrate, a trace on the substrate, and a ground plane.

A method of providing spark ignition for an engine or other equipment having a combustion chamber. A radio frequency wave or a microwave (RF/microwave) generator delivers radio frequency waves or microwaves to a transmit antenna inside the combustion chamber. At least one RF/microwave receive antenna is attached to an internal surface of the combustion chamber and comprises two or more RF/microwave focusing features with a spark gap between them. The transmit antenna wirelessly energizes the receive antenna, which generates a spark between the two focusing features.

Described is an apparatus for guiding an electromagnetic microwave, having: antenna surrounding walls, which define an interior space so as to surround therein at least an end region of an antenna of a microwave source, in particular laterally annularly as well as frontally; waveguide boundary walls, at least two of which are arranged in parallel to each other, wherein the waveguide boundary walls form a, in particular cuboid-shaped, waveguide having a substantially rectangular cross-section, wherein a cross-sectional plane is defined by a first direction that extends along a longitudinal direction of the antenna and a second direction that extends perpendicularly to the first direction, wherein it holds: 25>a/b>3, wherein a: is a width of the waveguide along the second direction, b: is a height of the waveguide along the first direction, wherein the apparatus is designed to let proceed a microwave from the interior space of the antenna surrounding walls into the waveguide.

An array antenna radiates an electromagnetic wave into a chamber of a plasma processing apparatus. The array antenna includes antennas and coupling prevention elements arranged at intervals between the antennas. Each of the coupling prevention elements includes a first member connected to a ceiling wall which is a ground surface in the chamber and a second member connected to a tip end of the first member or a vicinity of the tip end of the first member.

A high-frequency wave applicator for producing a plasma, including an inner conductor, and an outer conductor forming a coaxial structure, and a propagation medium of a high-frequency wave in a main propagation direction (x), including a passage dielectric of the wave having a sealing solid body disposed between the inner conductor and the outer conductor. Advantageously, the inner conductor has a first outer dimension d.sub.1 in a transverse direction (y), perpendicular to the main propagation direction (x), and the outer conductor has an inner dimension d.sub.2 in the transverse direction (y), such that 0.2<(d.sub.2−d.sub.1)/d.sub.2<0.55 allows improvement of the dissipation of the energy flows on the surface of the applicator.

Provided is a pipe holding connection structure configured so that the width of the entire structure is reduced and so that the number of parts and the number of assembly work processes are reduced. This pipe holding connection structure is provided with: a housing affixed so as to air-tightly close the opening of a vacuum container; a first pipe having a portion near an end portion thereof extending through both the opening and the housing; and a second pipe having a female thread part engaging with a male thread part located at the end portion. The pipe has a locking part. Fluid is caused to flow through both the pipes. Pieces of packing are provided between the pipe and the housing and between the pipe and an end portion of the pipe, respectively. This pipe holding connection structure can be used for a high-frequency antenna device.