Patent ID: 9526160
Filing Date: 2016-12-20
CPC Classification: H01J,H01P,H05H

Claim Text:
1. A cavity resonator incorporated in an apparatus for generating a plasma by microwave excitation, the cavity resonator comprising: an electrically conducting, resonator body having upper and lower walls spaced apart along a longitudinal axis, and a tubular side wall extending along the longitudinal axis to connect to the upper and lower walls at open ends thereof, the tubular side wall having an opening, the upper and lower walls and the tubular side wall bounding an interior cavity in communication with the opening; a waveguide coupled to the opening of the tubular side wall through an adjustable window and extending along a waveguide axis that is generally perpendicular to the longitudinal axis, for supplying a microwave at a resonant frequency to the interior cavity; an electrically insulating, reaction tube for conveying a gas to be ionized by the supplied microwave to generate the plasma within the reaction tube, the reaction tube extending longitudinally through the upper and lower walls in the interior cavity; and one or more electrically conducting elements spaced away from the tubular side wall, extending along the longitudinal axis in the interior cavity, and electrically connected to the upper and lower walls to correct fluctuations in the resonant frequency, the elements also being remote from, and not blocking, the opening to enable the supplied microwave to freely enter the interior cavity.