Abstract: A matching circuit is provided for delivering radio frequency electromagnetic energy from a radio frequency power supply to a variable impedance load such as a gas plasma. The matching network couples and impedance matches the power supply to the load. The matching network includes a ratio circuit for establishing a voltage ratio between the power supply and the load and a tuning circuit for tuning out a complex portion of the reactance of the load. Separation and control of the ratio and tuning variables is achieved through provision of a ratio control circuit comprising a lumped quarter wave transformer and a tuning control circuit comprising a variable tuning capacitance and a tuning inductance electrically connected in parallel to the load.