Patent ID: 6424232
Filing Date: 2002-07-23
Classification: H01J,H03H

Abstract:
An impedance matching network coupling a radio frequency power generator (RFPG) to a load, comprising:a phase detector coupled to said RFPG, said phase detector to detect a phase shift in a voltage and a current provided by said RFPG; a magnitude detector coupled to said RFPG, said magnitude detector to detect a magnitude of an impedance of said load; a fixed capacitance in parallel to said load; a variable capacitance in parallel to said load; an inductance in series with said load; a fixed capacitance in series with said load; a switching circuit coupled to said magnitude detector to couple and decouple said variable capacitance in parallel to said load to said ground depending on said magnitude of said impedance of said load detected by said magnitude detector, further coupled to said phase detector for coupling and decoupling said variable capacitance in parallel to said load to said ground depending on the magnitude of said impedance of said load detected by said magnitude detector and the phase shift in a voltage and a current detected by said phase detector, when said phase shift in said voltage and said current is approximately zero as detected by said phase detector.