Patent ID: 7755451
Filing Date: 2010-07-13
Classification: H01P

Abstract:
1. A directional coupler for an HF plasma process excitation configuration, the directional coupler comprising: a transmission line; a first coupling line configured for detecting reflected power by electrical coupling with the transmission line, the first coupling line being spaced apart from the transmission line and being terminated at least at one end with a termination resistance; and a second coupling line configured for detecting forward power by electrical coupling with the transmission line, the second coupling line being spaced apart from the transmission line and being terminated at least at one end with a termination resistance; wherein each coupling line has a predetermined and adjusted characteristic impedance, and the termination resistance of each of the coupling lines has a resistance value that corresponds within a tolerance to the characteristic impedance of the associated coupling line and further comprising a first ground reference member at ground potential and being defined by a ground surface, the transmission line is disposed in the same plane as the ground surface and the transmission line is electrically insulated from the ground surface, and wherein the forward power and the reflected power, or quantities describing the forward power and the reflected power, are decoupled from the transmission line with different coupling factors.