Generating large-area uniform microwave field for plasma excitation

Abstract

This study proposes a distributed input system to generate large-area uniform microwave field for the applications of plasma excitation or material processing. A microwave source is divided into four equal-amplitude and equal-phase waves through cascaded H-plane and E-plane power dividers. The wave in rectangular TE 10 mode is subsequently converted into cylindrical TE 11 mode and then propagates through a slightly deformed waveguide to form a circularly polarized wave. The four circularly polarized waves with a 2 2 input array are led into a reaction chamber to excite plasma or an applicator to process materials. An experiment was conducted, which verified the simulated results. The idea of generating uniform microwave field can be scaled to a much larger area if an n n input array is used © 2012 American Institute of Physics.